tag:theconversation.com,2011:/uk/topics/brain-1544/articlesBrain – The Conversation2024-03-27T14:52:40Ztag:theconversation.com,2011:article/2260902024-03-27T14:52:40Z2024-03-27T14:52:40ZAphantasia: ten years since I coined the term for lacking a mind’s eye – the journey so far<p>Words are powerful things. In 2015, with the help of a friend versed in the classics and two psychologist collaborators, I coined the term “aphantasia” to refer to the absence of a mind’s eye. We borrowed Aristotle’s word for the mind’s eye, “phantasia”, adding the prefix “a” to denote its absence. </p>
<p>The term was needed because we had encountered 21 people who, so far as they knew, had never been able to visualise things. Since then I have heard from over 10,000 people who recognised this feature of their psychological makeup in our description – and from several thousand at the opposite end of the spectrum, with “hyperphantasia”, imagery so vivid that it rivals “real seeing”. </p>
<p>It was clear from the start that, while intriguing, aphantasia was not disabling. Early contacts included Ed Catmull, the president of Pixar Disney, and Blake Ross, co-creator of the Mozilla Firefox internet browser, who described the moment he identified his aphantasia in a <a href="https://www.independent.co.uk/tech/aphantasia-software-engineer-blake-ross-writes-mindblowing-post-about-being-unable-to-imagine-things-a7000216.html">spirited Facebook post</a>.</p>
<p>We learned from the 21 participants in our original group that people usually discover they are aphantasic in their teens or twenties, often when sharing memories or trying to follow instructions to visualise. They had typically assumed, until then, that talk of the “mind’s eye” was metaphorical: suddenly they appreciate that when others speak of “seeing” a memorable moment from their past, or an absent loved one’s face, they actually can.</p>
<p>This original data hinted at some additional conclusions: in the absence of visual imagery, people with aphantasia often have a thin “autobiographical memory” of their personal past. They also frequently lack other forms of “sensory imagery”, like the ability to imagine the contrasting feel of velvet and satin. And more surprisingly, they often dream visually despite their lack of wakeful imagery.</p>
<p>Coining the term aphantasia unlocked a surge of popular and scientific interest: since 2015, <a href="https://pubmed.ncbi.nlm.nih.gov/?term=Aphantasia">over 50 papers</a> have been published exploring aphantasia. The enthusiasm of many of our participants, glad that a puzzling feature of their psychology has finally been named and studied, has been a heart-warming aspect of this work. </p>
<p>I have recently reviewed this new field of research in <a href="https://doi.org/10.1016/j.tics.2024.02.007">Trends in Cognitive Sciences</a>. What are the main conclusions to date?</p>
<h2>Not a hindrance</h2>
<p>In defiance of Aristotle’s view that the “soul never thinks without an image”, people with aphantasia think clearly and effectively. </p>
<p>A wide range of standard tests of memory and thinking – “cognition” – show only borderline changes, if any, in aphantasia. But one aspect of memory does appear to be affected, as our initial work had suggested: the richness of autobiographical memory is generally reduced in aphantasia, together with the linked ability to conjure up vivid future scenarios. </p>
<p>Recent studies have also supported our initial suspicions that imagery in other senses is often affected in aphantasia, and visual dreaming is often preserved.</p>
<p>Other associations have come to light. A subgroup of people with aphantasia describe difficulty in recognising faces, and aphantasia may, more generally, be linked to subtle alterations in the way the world is perceived. </p>
<p>Aphantasia occurs with autistic spectrum disorder in some of our participants, while people with hyperphantasia are more likely to experience synaesthesia, in which, for example, hearing sounds gives rise to seeing colours. </p>
<p>Aphantasia appears to nudge people in the direction of science and technology professions, while traditionally “creative” trades are over-represented among those with hyperphantasia, though there are many exceptions.</p>
<h2>A genetic trait?</h2>
<p>Aphantasia occurs in around 4% of the population. If you are aphantasic, your siblings are ten times more likely to share this trait than would be expected by chance.</p>
<p>We hope to identify a possible genetic basis for imagery vividness extremes with the help of large biobanks (studies, like UK Biobank, enrolling large numbers of participants from whom many forms of data, including genetic details, have been gathered). The likelihood that aphantasia is not one “thing” but rather occurs in a range of subtypes, will complicate this hunt. </p>
<p>You may be wondering whether an experience as subjective as the vividness of imagery can be relied on at all as a target for science. The patterns in the results I have just described suggest that reports of imagery vividness are meaningful. But, reassuringly, other lines of objective evidence point in the same direction.</p>
<p>If you have imagery, and you imagine looking into the Sun, your pupils will constrict – not so in people with aphantasia. Listening to scary stories alters skin conductance in those with imagery (we sweat!) – not so in people with aphantasia. </p>
<p>Work directly examining brain activity suggests that differences in brain connectivity between people with aphantasia and hyperphantasia help to explain why thought translates into image more readily for some of us than others. </p>
<p>Why did our modest coinage of a term excite so much interest? One of the most distinctive features of our human lives is that we spend much of them in our heads. We are, therefore, bound to be intrigued by one another’s inner lives. </p>
<p>Visual imagery is the most frequently reported conscious experience. Those of us with imagery are therefore startled to discover that others inhabit quite different mental worlds. Those of us who lack it are glad to have met a word capturing that difference.</p><img src="https://counter.theconversation.com/content/226090/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Zeman receives funding from:
Arts & Humanities Research Council
Tibore Foundation </span></em></p>Around 4% of the population are unable to see things in their mind’s eye. Except when they are dreaming.Adam Zeman, Professor of Cognitive and Behavioural Neurology, University of ExeterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2254122024-03-19T16:12:24Z2024-03-19T16:12:24ZThe middle-aged brain changes a lot – and it’s key to understanding dementia<p>Our brains change more rapidly at various times of our lives, as though life’s clock was ticking faster than usual. Childhood, adolescence and very old age are good examples of this. Yet for much of adulthood, the same clock seems to tick fairly regularly. One lap around the Sun; one year older. </p>
<p>However, there may be a stage of life when the brain’s clock starts speeding up. The brain starts changing without you necessarily noticing it. It may even be caused (partly) by what’s in your blood. This stage of brain ageing during your 40s to 50s, or “<a href="https://doi.org/10.1016/j.tins.2024.02.001">middle-ageing</a>”, may predict your future health.</p>
<p>Psychologists studying how our mental faculties change with age find that they decline gradually, starting in our <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6367038/">20s and 30s</a>. However, when assessing people’s memory of everyday events, the change over time appears to be especially <a href="https://pubmed.ncbi.nlm.nih.gov/28798624/">rapid and unstable during middle age</a>. That is, even among healthy people, some experience rapidly deteriorating memory, while for others, it may even improve.</p>
<p>This suggests that the brain may be going through accelerating, as opposed to gradual, change during this period. Several structures of the brain have been found to change in midlife. The hippocampus, an area critical for forming <a href="https://www.sciencedirect.com/science/article/pii/S0197458013001590?via%3Dihub">new memories</a>, is one of them. </p>
<p>It shrinks throughout much of adulthood, and this shrinkage seems to accelerate around the time of middle age. Abrupt shifts in the size and function of the hippocampus during middle age could underlie memory changes like the ones <a href="https://www.nature.com/articles/s41598-020-64595-z">mentioned above</a>.</p>
<p>Ultimately, what allows the brain to carry out its functions are the connections between brain cells – the white matter. These connections mature slowly throughout adulthood, especially the ones connecting areas of the brain that deal with cognitive functions such as memory, reasoning and language. </p>
<p>Interestingly, during middle age, many of them go through a turning point, from <a href="https://www.nature.com/articles/ncomms5932">gaining volume to losing volume</a>. This means that signals and information cannot be <a href="https://doi.org/10.1038/s41593-023-01272-0">transmitted as fast</a>. Reaction time starts <a href="https://www.frontiersin.org/articles/10.3389/fnagi.2021.661514/full">deteriorating </a> around the same time.</p>
<p>Through the white matter connections, brain areas talk to each other and form interconnected networks that can perform cognitive and sensory functions, including memory or vision. While the sensory networks deteriorate gradually throughout adulthood, the cognitive networks start deteriorating <a href="https://www.pnas.org/doi/10.1073/pnas.1415122111">faster during middle age</a>, especially those involved in memory.</p>
<p>Much like how highly connected people in society tend to form cliques with each other, brain regions do the same through their connections. This organisation of the brain’s communication allows us to perform some of the complex tasks we might take for granted, such as planning our days and making decisions. </p>
<p>The brain seems to peak in this regard by the <a href="https://onlinelibrary.wiley.com/doi/10.1111/psyp.14159">time we hit middle age</a>. Some have even referred to middle age as a “<a href="https://www.psychologicalscience.org/observer/financial-decision-making-and-the-aging-brain">sweet spot</a>” for some types of decision-making, but then the network “cliques” start to break up.</p>
<p>It’s worth stating at this point why these subtle changes matter. The global population aged 60 and over is set to roughly <a href="https://www.nature.com/articles/nature06516">double by 2050</a>, and with this, unfortunately, will come a considerable increase in <a href="https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(21)00249-8/fulltext">dementia case numbers</a>. </p>
<figure class="align-center ">
<img alt="A blurry photo of an elderly couple." src="https://images.theconversation.com/files/582395/original/file-20240317-22-pddnzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/582395/original/file-20240317-22-pddnzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=417&fit=crop&dpr=1 600w, https://images.theconversation.com/files/582395/original/file-20240317-22-pddnzn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=417&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/582395/original/file-20240317-22-pddnzn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=417&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/582395/original/file-20240317-22-pddnzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=524&fit=crop&dpr=1 754w, https://images.theconversation.com/files/582395/original/file-20240317-22-pddnzn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=524&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/582395/original/file-20240317-22-pddnzn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=524&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">As the population ages, dementia cases will inevitably rise.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/old-couple-man-woman-still-together-225478723">oneinchpunch/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Focus has been too much on the brain in old age</h2>
<p>Science has long focused on very old age, when the detrimental effects of time are most obvious, but, by then, it can often be too late to intervene. Middle age could be a period when we can detect early risk factors of future cognitive decline, such as in <a href="https://www.thelancet.com/article/S0140-6736(20)30367-6/fulltext">dementia</a>. Critically, the window of opportunity to intervene may also still be open.</p>
<p>So, how do we detect changes without having to give everyone an expensive brain scan? As it turns out, the contents of blood may cause the <a href="https://www.nature.com/articles/s41593-022-01238-8">brain to age</a>. With time, our cells and organs slowly deteriorate, and the immune system can react to this by starting the process of inflammation. Inflammatory molecules can then end up in the bloodstream, make their way to the brain, interfere with its <a href="https://www.nature.com/articles/nature10357">normal functioning</a> and possibly impair cognition.</p>
<p>In a fascinating study, scientists from Johns Hopkins and the University of Mississippi analysed the presence of inflammatory molecules in the blood of middle-aged adults and were able to predict future cognitive change <a href="https://www.neurology.org/doi/10.1212/WNL.0000000000007094?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed">20 years down the line</a>. This highlights an important emerging idea: age in terms of biological measures is more informative about your future health than age in terms of years lived. </p>
<p>Importantly, biological age can often be <a href="https://www.nature.com/articles/s43587-021-00044-4">estimated</a> with readily available and cost-effective tests used in the clinic.</p>
<p>“Middle ageing” may be more consequential for our future brain health than we think. The hurried ticking of the clock could be slowed from outside the brain. For example, physical exercise confers some of its beneficial effects on the brain through <a href="https://www.nature.com/articles/s41593-022-01238-8">blood-borne messengers</a>. These can work to oppose the effects of time. If they could be harnessed, they might steady the pendulum.</p><img src="https://counter.theconversation.com/content/225412/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span><a href="mailto:y.nolan@ucc.ie">y.nolan@ucc.ie</a> receives funding from Science Foundation Ireland. She s affiliated with APC Microbiome Ireland. </span></em></p><p class="fine-print"><em><span>Sebastian Dohm-Hansen Allard does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Middle age could be a period when we can detect early risk factors of future cognitive decline.Sebastian Dohm-Hansen Allard, PhD Candidate, Anatomy and Neuroscience, University College CorkYvonne Nolan, Professor in Neuroscience, University College CorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2256032024-03-15T17:15:03Z2024-03-15T17:15:03ZTapeworm larvae found in man’s brain – how did they get there?<figure><img src="https://images.theconversation.com/files/582158/original/file-20240315-24-ctqzsd.jpg?ixlib=rb-1.1.0&rect=40%2C0%2C6669%2C4476&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/study-tapeworm-infection-caused-by-ingesting-1273229722">Rattiya Thongdumhyu/Shutterstock</a></span></figcaption></figure><p>We have all found ourselves in a place we would rather not be, a school reunion, the never-ending work meeting or a distant relative’s wedding reception. In such situations, it is often a good option to make the best of it. Well, this isn’t just the case for people, it is also an occurrence in the world of parasites – those lifeforms that live in and on us. This was the case for <em>Taenia solium</em>, or pig tapeworm which <a href="https://amjcaserep.com/abstract/index/idArt/943133">found itself</a> in an unlikely place. </p>
<p>A middle-aged man from Florida with a history of migraines went to the doctor as his headaches were becoming worse and weren’t responding to his usual drugs. The 52-year-old was sent for a CT scan, which revealed something alarming: his brain was infested with tapeworm cysts.</p>
<p>The most common route of infection is eating undercooked infected pork that contains tapeworm cysts, known as cysticercus. </p>
<p>When the parasite senses the digestive juices of your small intestine, it then knows it is time to use its curled hooks and four suckers and attach to your gut. Once here, the tapeworm is living its best life; growing to around two metres long and potentially making a home in you for up to five years. </p>
<p>During this time, the parasite will release thousands of eggs, either individually or via releasing segments of its body packed full of eggs, which all pass out in your faeces. This form of infection is largely symptomless and easily treated with antihelminthics (anti-parasite drugs) with minimal complications. </p>
<p>Although the reported patient acknowledged a habit of eating undercooked bacon, this would not explain the parasite being found in his brain, as consuming cysticercus in undercooked pork would only result in an intestinal infection. </p>
<h2>Poor hygiene is the likely cause</h2>
<p>The authors of this new study therefore hypothesised that the patient may have been infected with the intestinal form of the parasite and re-infected himself with eggs passed in his faeces through poor hygiene. </p>
<p>In countries with limited sanitation and where faeces can be used as fertiliser, the eggs people pass are usually eaten by pigs. Once in the pig, they hatch and make their way to the pig’s muscle to form cysticercus, waiting to be consumed again by humans. </p>
<p>In this case, the parasite has reverted to the cysticercus form and while seeking out muscle has accidentally made its way into the brain via the blood stream resulting in a condition called <a href="https://www.cdc.gov/parasites/resources/pdf/npis_in_us_neurocysticercosis.pdf">neurocysticercosis</a>. The parasite has still made the best of the situation, as it could carry on its lifecycle if scavenged following the death of the host.</p>
<p>Neurocysticercosis is also treated with antihelminthics, but the resulting immune response in the brain can cause more harm than good and needs to be turned down with anti-inflammatory drugs. </p>
<p>The reported patient opted for this dual treatment and is recovering with reduced brain lesions and headaches. </p>
<p>If untreated, neurocysticercosis can lead to seizures and is a <a href="https://onlinelibrary.wiley.com/doi/10.1111/epi.14068">leading cause</a> of epilepsy in developing nations with poor sanitation where cases are prevalent. With increased immigration from countries where the tapeworm is endemic, there is also an increase in cases even in countries where reports in livestock are rare.</p>
<p>The best way to avoid this unwanted guest in your intestine, or brain where neither host nor parasite are happy, is good personal hygiene. </p>
<p>Pigs are traditionally a host for many parasites – after all, there is a reason pork was forbidden in many cultures, and I personally avoid the <a href="https://www.theguardian.com/lifeandstyle/2013/sep/21/chefs-pork-pink">current fashion</a> for “rare” pork, even in the fanciest restaurants. Take a cue from the parasite: make the best of the situation and opt for fully cooked pork and you will be fine.</p><img src="https://counter.theconversation.com/content/225603/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Worthington works for Lancaster University. He receives funding from DSTL, the Wellcome Trust and the Royal Society. </span></em></p>A man from Florida was found to have tapeworm cysts in his brain.John Worthington, Senior Lecturer in Infection Biology, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2228542024-02-29T21:48:23Z2024-02-29T21:48:23ZBetter sleep is a protective factor against dementia<figure><img src="https://images.theconversation.com/files/573581/original/file-20240117-23-vqzz7m.jpg?ixlib=rb-1.1.0&rect=60%2C0%2C6720%2C4456&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lack of sleep, or poor quality sleep, is one of the risk factors for developing Alzheimer's disease. Fortunately, there are ways to improve sleep.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Dementia is a progressive loss of cognitive abilities, such as memory, that is significant enough to have an impact on a person’s daily activities. </p>
<p>It can be caused by a number of different diseases, including <a href="https://alzheimer.ca/en/about-dementia/what-alzheimers-disease">Alzheimer’s</a>, which is the most common form. Dementia is caused by a loss of neurons over a long period of time. Since, by the time symptoms appear, many changes in the brain have already occurred, many scientists are focusing on studying the risk and protective factors for dementia. </p>
<p>A risk factor, or conversely, a protective factor, is a condition or behaviour that increases or reduces the risk of developing a disease, but does not guarantee either outcome. Some risk factors for Alzheimer’s disease and dementia, such as age or genetics, are not modifiable, but there are several other factors we can influence, <a href="https://www.thelancet.com/article/S0140-6736(20)30367-6/fulltext">specifically lifestyle habits and their impact on our overall health</a>.</p>
<p>These risk factors include depression, lack of physical activity, social isolation, high blood pressure, obesity, diabetes, excessive alcohol consumption and smoking, as well as poor sleep.</p>
<p>We have been focusing our research on the question of sleep for over 10 years, particularly in the context of the <a href="https://www.nhlbi.nih.gov/science/framingham-heart-study-fhs">Framingham Heart Study</a>. In this large community-based cohort study, ongoing since the 1940s, the health of surviving participants has been monitored to the present day. As researchers in sleep medicine and epidemiology, we have expertise in researching the role of sleep and sleep disorders in cognitive and psychiatric brain aging. </p>
<p>As part of our research, we monitored and analyzed the sleep of people aged 60 and over to see who did — or did not — develop dementia. </p>
<h2>Sleep as a risk or protective factor against dementia</h2>
<p>Sleep appears to play an essential role in a number of brain functions, such as memory. Good quality sleep <a href="https://jamanetwork.com/journals/jamaneurology/fullarticle/2793873">could therefore play a vital role in preventing dementia</a>.</p>
<p>Sleep is important for maintaining <a href="https://www.science.org/doi/10.1126/science.1241224">good connections in the brain</a>. Recently, research has revealed that sleep seems to have a function similar to that of a garbage truck for the brain: <a href="https://doi.org/10.1016/j.mad.2023.111899">deep sleep could be crucial for eliminating metabolic waste from the brain</a>, including clearing certain proteins, such as those known to accumulate in the brains of people with Alzheimer’s disease. </p>
<p>However, the links between deep sleep and dementia still have to be clarified.</p>
<h2>What is deep sleep?</h2>
<p>During a night’s sleep, we go through several <a href="http://ceams-carsm.ca/en/a-propos-du-sommeil/">sleep stages</a> that succeed one another and are repeated. </p>
<p>NREM sleep (non-rapid eye movement sleep) is divided into light NREM sleep (NREM1 stage), NREM sleep (NREM2 stage) and deep NREM sleep, also called slow-wave sleep (NREM3 stage). The latter is associated with several restorative functions. Next, REM sleep (rapid eye movement sleep) is the stage generally associated with the most vivid dreams. An adult generally spends around 15 to 20 per cent of each night in deep sleep, if we add up all the periods of NREM3 sleep. </p>
<p>Several sleep changes are common in adults, such as going to bed and waking up earlier, sleeping for shorter periods of time and less deeply, and waking up more frequently during the night.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/579041/original/file-20240229-16-efo9mx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/579041/original/file-20240229-16-efo9mx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/579041/original/file-20240229-16-efo9mx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=279&fit=crop&dpr=1 600w, https://images.theconversation.com/files/579041/original/file-20240229-16-efo9mx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=279&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/579041/original/file-20240229-16-efo9mx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=279&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/579041/original/file-20240229-16-efo9mx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=350&fit=crop&dpr=1 754w, https://images.theconversation.com/files/579041/original/file-20240229-16-efo9mx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=350&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/579041/original/file-20240229-16-efo9mx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=350&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sleep stages, and the role of deep sleep for brain health.</span>
<span class="attribution"><span class="source">(Andrée-Ann Baril)</span></span>
</figcaption>
</figure>
<h2>Loss of deep sleep linked to dementia</h2>
<p>Participants in the <a href="https://jamanetwork.com/journals/jamaneurology/fullarticle/2810957">Framingham Heart Study</a> were assessed using a sleep recording — known as polysomnography — on two occasions, approximately five years apart, in 1995-1998 and again in 2001-2003. </p>
<p>Many people showed a reduction in their deep slow-wave sleep over the years, as is to be expected with aging. Conversely, the amount of deep sleep in some people remained stable or even increased. </p>
<p>Our team of researchers from the Framingham Heart Study followed 346 participants aged 60 and over for a further 17 years to observe who developed dementia and who did not. </p>
<p>Progressive loss of deep sleep over time was associated with an increased risk of dementia, whatever the cause, and particularly Alzheimer’s type dementia. These results were independent of many other risk factors for dementia.</p>
<p>Although our results do not prove that loss of deep sleep causes dementia, they do suggest that it could be a risk factor in the elderly. Other aspects of sleep may also be important, such as its duration and quality. </p>
<h2>Strategies to improve deep sleep</h2>
<p>Knowing the impact of a lack of deep sleep on cognitive health, what strategies can be used to improve it? </p>
<p>First and foremost, if you’re experiencing sleep problems, it’s worth talking to your doctor. Many sleep disorders are underdiagnosed and treatable, particularly through behavioural (i.e. non-medicinal) approaches. </p>
<p>Adopting good sleep habits can help, such as going to bed and getting up at consistent times or avoiding bright or blue light in bed, like that of screens. </p>
<p>You can also avoid caffeine, limit your alcohol intake, maintain a healthy weight, be physically active during the day, and sleep in a comfortable, dark and quiet environment.</p>
<p>The role of deep sleep in preventing dementia remains to be explored and studied. Encouraging sleep with good lifestyle habits could have the potential to help us age in a healthier way.</p><img src="https://counter.theconversation.com/content/222854/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrée-Ann Baril received funding from the Sleep Research Society Foundation, the Alzheimer Society of Canada, the Canadian Institutes of Health Research, Banting Postdoctoral Fellowships, the Fondation de l'Hôpital du Sacré-Coeur de Montréal, the Université de Montréal and speaking fees from Eisai.</span></em></p><p class="fine-print"><em><span>Matthew Pase received funding from the National Health and Medical Research Council of Australia, National Institute on Aging, Dementia Australia, Alzheimer's Association, National Heart Foundation of Australia, Australian Research Council, Stroke Foundation, Brain Foundation, Alzheimer's Drug Discovery Foundation, Rebecca L Cooper Medical Research Foundation, and Bethlehem Griffiths Research Foundation.</span></em></p>Sleep appears to play an essential role in a number of brain functions, such as memory. So good quality sleep could play a vital role in preventing dementia.Andrée-Ann Baril, Professeure-chercheure adjointe au Département de médecine, Université de MontréalMatthew Pase, Associate Professor of Neurology and Epidemiology, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2242162024-02-28T22:42:24Z2024-02-28T22:42:24ZMounting research shows that COVID-19 leaves its mark on the brain, including with significant drops in IQ scores<figure><img src="https://images.theconversation.com/files/577796/original/file-20240226-16-yg36tj.jpg?ixlib=rb-1.1.0&rect=7%2C7%2C4985%2C3585&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Research shows that even mild COVID-19 can lead to the equivalent of seven years of brain aging.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/brain-fog-conceptual-illustration-royalty-free-illustration/1740384064?phrase=brain+fog&adppopup=true">Victor Habbick Visions/Science Photo Library via Getty Images</a></span></figcaption></figure><p>From the very early days of the pandemic, <a href="https://www.everydayhealth.com/emotional-health/brain-fog/guide/">brain fog</a> <a href="https://www.health.harvard.edu/blog/what-is-covid-19-brain-fog-and-how-can-you-clear-it-2021030822076">emerged as a significant health condition</a> that many experience after COVID-19. </p>
<p>Brain fog is a colloquial term that describes a state of mental sluggishness or lack of clarity and haziness that makes it difficult to concentrate, remember things and think clearly.</p>
<p>Fast-forward four years and there is now abundant evidence that being infected with SARS-CoV-2 – the virus that causes COVID-19 – <a href="https://doi.org/10.1038/s41591-022-02001-z">can affect brain health in many ways</a>.</p>
<p>In addition to brain fog, COVID-19 can lead to <a href="https://doi.org/10.1038/s41591-023-02521-2">an array of problems</a>, including headaches, seizure disorders, strokes, sleep problems, and tingling and paralysis of the nerves, as well as <a href="https://www.bmj.com/content/376/bmj-2021-068993">several mental health disorders</a>. </p>
<p>A large and growing body of evidence amassed throughout the pandemic details the many ways that <a href="https://doi.org/10.1126/science.adl0867">COVID-19 leaves an indelible mark</a> on the brain. But the specific pathways by which the virus does so are still being elucidated, and curative treatments are nonexistent.</p>
<p>Now, two new studies published in the New England Journal of Medicine shed further light on the <a href="https://doi.org/10.1056/NEJMe2400189">profound toll of COVID-19 on cognitive health</a>. </p>
<p>I am a <a href="https://scholar.google.com/citations?user=DtuRVcUAAAAJ">physician scientist</a>, and I have been devoted to studying <a href="https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects/index.html">long COVID</a> since early patient reports about this condition – even before the term “long COVID” was coined. I have testified before the U.S. Senate as <a href="https://www.help.senate.gov/hearings/addressing-long-covid-advancing-research-and-improving-patient-care">an expert witness on long COVID</a> and have <a href="https://scholar.google.com/citations?view_op=search_authors&hl=en&mauthors=label:long_covid">published extensively</a> on this topic.</p>
<h2>How COVID-19 leaves its mark on the brain</h2>
<p>Here are some of the most important studies to date documenting how COVID-19 affects brain health: </p>
<ul>
<li><p>Large epidemiological analyses showed that people who had COVID-19 were at an <a href="https://doi.org/10.1038/s41591-022-02001-z">increased risk of cognitive deficits</a>, such as memory problems.</p></li>
<li><p>Imaging studies done in people before and after their COVID-19 infections show <a href="https://doi.org/10.1038/s41586-022-04569-5">shrinkage of brain volume</a> and <a href="https://theconversation.com/even-mild-cases-of-covid-19-can-leave-a-mark-on-the-brain-such-as-reductions-in-gray-matter-a-neuroscientist-explains-emerging-research-178499">altered brain structure after infection</a>. </p></li>
<li><p>A study of people with mild to moderate COVID-19 showed significant prolonged inflammation of the brain and <a href="https://doi.org/10.1073/pnas.2217232120">changes that are commensurate with seven years of brain aging</a>. </p></li>
<li><p>Severe COVID-19 that requires hospitalization or intensive care may result in cognitive deficits and other brain damage that are <a href="https://doi.org/10.21203/rs.3.rs-3818580/v1">equivalent to 20 years of aging</a>. </p></li>
<li><p>Laboratory experiments in human and mouse brain <a href="https://hsci.harvard.edu/organoids">organoids</a> designed to emulate changes in the human brain showed that SARS-CoV-2 infection triggers the <a href="https://doi.org/10.1126/sciadv.adg2248">fusion of brain cells</a>. This effectively short-circuits brain electrical activity and compromises function. </p></li>
<li><p>Autopsy studies of people who had severe COVID-19 but died months later from other causes showed that <a href="https://doi.org/10.1038/s41586-022-05542-y">the virus was still present in brain tissue</a>. This provides evidence that contrary to its name, SARS-CoV-2 is not only a respiratory virus, but it can also enter the brain in some individuals. But whether the persistence of the virus in brain tissue is driving some of the brain problems seen in people who have had COVID-19 is not yet clear.</p></li>
<li><p>Studies show that even when the virus is mild and exclusively confined to the lungs, it can still provoke inflammation in the brain and <a href="https://doi.org/10.1016/j.cell.2022.06.008">impair brain cells’ ability to regenerate</a>.</p></li>
<li><p>COVID-19 can also <a href="https://doi.org/10.1038/s41593-024-01576-9">disrupt the blood brain barrier</a>, the shield that protects the nervous system – which is the control and command center of our bodies – making it “leaky.” Studies using imaging to assess the brains of people hospitalized with COVID-19 showed disrupted or leaky blood brain barriers in those who experienced brain fog.</p></li>
<li><p>A large preliminary analysis pooling together data from 11 studies encompassing almost 1 million people with COVID-19 and more than 6 million uninfected individuals showed that COVID-19 <a href="https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4716751">increased the risk of development of new-onset dementia</a> in people older than 60 years of age.</p></li>
</ul>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/7RjItCm_YpU?wmode=transparent&start=6" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Autopsies have revealed devastating damage in the brains of people who died with COVID-19.</span></figcaption>
</figure>
<h2>Drops in IQ</h2>
<p>Most recently, a new study published in the New England Journal of Medicine <a href="https://doi.org/10.1056/NEJMoa2311330">assessed cognitive abilities</a> such as memory, planning and spatial reasoning in nearly 113,000 people who had previously had COVID-19. The researchers found that those who had been infected had significant deficits in memory and executive task performance. </p>
<p>This decline was evident among those infected in the early phase of the pandemic and <a href="https://theconversation.com/delta-variant-makes-it-even-more-important-to-get-a-covid-19-vaccine-even-if-youve-already-had-the-coronavirus-164203">those infected when the delta</a> and <a href="https://theconversation.com/will-omicron-the-new-coronavirus-variant-of-concern-be-more-contagious-than-delta-a-virus-evolution-expert-explains-what-researchers-know-and-what-they-dont-169020">omicron variants</a> were dominant. These findings show that the risk of cognitive decline did not abate as the pandemic virus evolved from the ancestral strain to omicron.</p>
<p>In the same study, those who had mild and resolved COVID-19 showed cognitive decline equivalent to a three-point loss of IQ. In comparison, those with unresolved persistent symptoms, such as people with persistent shortness of breath or fatigue, had a six-point loss in IQ. Those who had been admitted to the intensive care unit for COVID-19 had a nine-point loss in IQ. Reinfection with the virus contributed an additional two-point loss in IQ, as compared with no reinfection.</p>
<p>Generally the average IQ is about 100. An IQ above 130 indicates a highly gifted individual, while an IQ below 70 generally indicates a level of intellectual disability that may require significant societal support.</p>
<p>To put the finding of the New England Journal of Medicine study into perspective, I estimate that a three-point downward shift in IQ would increase the number of U.S. adults with an IQ less than 70 from 4.7 million to 7.5 million – an increase of 2.8 million adults with a level of cognitive impairment that requires significant societal support.</p>
<p>Another study in the same issue of the New England Journal of Medicine involved more than 100,000 Norwegians between March 2020 and April 2023. It <a href="https://doi.org/10.1056/NEJMc2311200">documented worse memory function</a> at several time points up to 36 months following a positive SARS-CoV-2 test. </p>
<h2>Parsing the implications</h2>
<p>Taken together, these studies show that COVID-19 poses a serious risk to brain health, even in mild cases, and the effects are now being revealed at the population level. </p>
<p>A recent analysis of the <a href="https://www.census.gov/programs-surveys/cps.html">U.S. Current Population Survey</a> showed that after the start of the COVID-19 pandemic, an <a href="https://www.nytimes.com/2023/11/13/upshot/long-covid-disability.html">additional 1 million working-age Americans</a> reported having “serious difficulty” remembering, concentrating or making decisions than at any time in the preceding 15 years. Most disconcertingly, this was mostly driven by younger adults between the ages of 18 to 44. </p>
<p>Data from the European Union shows a similar trend – in 2022, 15% of people in the EU <a href="https://ec.europa.eu/eurostat/en/web/products-eurostat-news/w/ddn-20240129-1">reported memory and concentration issues</a>.</p>
<p>Looking ahead, it will be critical to identify who is most at risk. A better understanding is also needed of how these trends might affect the educational attainment of children and young adults and the economic productivity of working-age adults. And the extent to which these shifts will influence the epidemiology of dementia and Alzheimer’s disease is also not clear. </p>
<p>The growing body of research now confirms that COVID-19 should be considered a virus with a significant impact on the brain. The implications are far-reaching, from individuals experiencing cognitive struggles to the potential impact on populations and the economy. </p>
<p>Lifting the fog on the true causes behind these cognitive impairments, including brain fog, will require years if not decades of concerted efforts by researchers across the globe. And unfortunately, nearly everyone is a test case in this unprecedented global undertaking.</p><img src="https://counter.theconversation.com/content/224216/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ziyad Al-Aly receives funding from the U.S. Department of Veterans Affairs. </span></em></p>Two new high-profile studies add to the increasingly worrisome picture of how even mild cases of COVID-19 can have detrimental effects on brain health.Ziyad Al-Aly, Chief of Research and Development, VA St. Louis Health Care System. Clinical Epidemiologist, Washington University in St. LouisLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2202672024-02-28T12:34:47Z2024-02-28T12:34:47ZLow-level blasts from heavy weapons can cause traumatic brain injury − 2 engineers explain the physics of invisible cell death<figure><img src="https://images.theconversation.com/files/574230/original/file-20240207-24-4417vk.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3500%2C2331&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Low-level blasts can cause physical changes in the brain.</span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/RussiaUkraineWarFrenchWeapons/0b650af49a654704a4bef82ae8a4bc93">Libkos/AP Photo</a></span></figcaption></figure><p>When the force of a blast shoots a round out of a large-caliber rifle, howitzer or M1 Abrams tank gun, the teams of people operating these weapons are exposed to <a href="https://health.mil/Reference-Center/Fact-Sheets/2023/07/18/Low-Level-Blast-Service-Members-Fact-Sheet">low-level blasts</a> that can cause <a href="https://www.brainline.org/qa/what-do-blast-injuries-do-your-brain">traumatic brain injuries</a>.</p>
<p>Low-level blasts do not cause visible trauma, such as bleeding from ruptured eardrums, and they don’t cause injury through violent head motion, such as a concussion. Yet, these blasts can cause <a href="https://pubmed.ncbi.nlm.nih.gov/27291520/">physical changes in the brain</a> that lead to a host of neuropsychiatric symptoms.</p>
<p>The link between the force of a blast and the resulting changes in the brain is not completely understood. So our team of <a href="https://scholar.google.com/citations?user=VlzdxcEAAAAJ&hl=en">engineers and</a> <a href="https://scholar.google.com/citations?user=aIl1GHoAAAAJ&hl=en">scientists in</a> the <a href="https://www.panther.engr.wisc.edu/">PANTHER program</a>, funded by the Department of Defense, is using physics to elucidate how blasts cause traumatic brain injury.</p>
<h2>What is a blast?</h2>
<p>When a weapon like a rifle <a href="https://www.hunter-ed.com/national/studyGuide/Video-How-a-Cartridge-Is-Fired/201099_92813/">is fired</a>, the round is initially in its barrel. Pulling the trigger engages a primer that produces a flame, igniting the propellant. This chemical reaction releases stored energy and creates high-pressure, rapidly expanding gas. This is the blast.</p>
<p>The rate and magnitude of gas expansion are often so extreme that they <a href="https://www.americanscientist.org/article/high-speed-imaging-of-shock-waves-explosions-and-gunshots">create a shock wave</a>, where high-pressure air molecules travel outward faster than the speed of sound. This invisible pulse of high pressure carries a tremendous amount of energy. It’s the same force that can propel a 24-pound warhead out of the muzzle of a howitzer to hit a target 19 miles (30.6 kilometers) away. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/574231/original/file-20240207-29-yowd6.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Cross-section of a cartridge" src="https://images.theconversation.com/files/574231/original/file-20240207-29-yowd6.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/574231/original/file-20240207-29-yowd6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/574231/original/file-20240207-29-yowd6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/574231/original/file-20240207-29-yowd6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/574231/original/file-20240207-29-yowd6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/574231/original/file-20240207-29-yowd6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/574231/original/file-20240207-29-yowd6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This cross-section shows: 1. bullet; 2. case; 3. gunpowder; 4. rim; and 5. primer.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Cartridge_cross_section.svg">Glrx/Quadrell via Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>After the blast leaves the gun’s muzzle, it dissipates quickly because it is free to expand in the open air. This is when the high pressure washes over the bodies of nearby people. </p>
<p>The blast from the muzzle of a large gun like the <a href="https://youtu.be/1anCHKq6ESg?feature=shared">M777 howitzer</a> does not pulverize rocks or knock someone off their feet. But some of the blast pressure enters the body, passing through the skin and rigid skull bone and into the soft tissue of the brain. </p>
<h2>Linking blast to brain injury</h2>
<p>As blast pressure enters the brain, it is initially compressive, meaning it squeezes the tissue equally from all sides. Because brain tissue is <a href="https://doi.org/10.1007/s11831-019-09352-w">largely composed of water molecules</a>, which are difficult to compress, this type of pressure <a href="https://link.springer.com/article/10.1007/s10439-019-02437-4">tends to cause little known harm</a> to cells. </p>
<p>An initially compressive wave, or positive pressure wave, that squeezes brain tissue changes when it bounces off the inside of the skull. It is reflected as a tensile wave, or negative pressure wave, which tends to pull brain tissue apart. With low enough pressures, <a href="https://doi.org/10.2217/cnc-2017-0011">micron-sized bubbles can form</a> in a process called cavitation. These bubbles can grow 10 to 50 times their initial size over the course of less than a tenth of a millisecond, rapidly stretching the adjacent brain tissue.</p>
<p>Experiments from our lab have shown that the deformation caused by cavitation bubbles happens so rapidly – like the speed of a bullet – that cells tend to <a href="https://www.sciencedirect.com/science/article/pii/S2666522021000149">get torn apart</a>. The extreme speed of stretching and squeezing causes nearby brain cells to die immediately. Afterward, we see only fragments where healthy cells used to be.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/577687/original/file-20240223-20-xi71p2.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram showing blast pressure creating microbubbles in the brain after reflecting off surfaces, stretching and destroying cells in a process called cavitation." src="https://images.theconversation.com/files/577687/original/file-20240223-20-xi71p2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577687/original/file-20240223-20-xi71p2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=361&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577687/original/file-20240223-20-xi71p2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=361&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577687/original/file-20240223-20-xi71p2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=361&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577687/original/file-20240223-20-xi71p2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=454&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577687/original/file-20240223-20-xi71p2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=454&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577687/original/file-20240223-20-xi71p2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=454&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This diagram depicts how blast pressure from a gun can result in brain trauma.</span>
<span class="attribution"><span class="source">Alice Lux Fawzi and Manik Bansal</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Cell death is the physical root cause of brain injury. In the lab, when the cells that make up brain tissue are deformed at a magnitude and rate beyond what they can withstand, they die – either immediately, as in the case of blast-induced cavitation, or slowly over six to 24 hours, as in most brain injuries from blunt impacts such as concussions. </p>
<p>In low-level blast exposure, the cavitation bubbles are very small, and the trauma is contained to the small area around them. However, repeated exposure to blasts can lead to an accumulation of these microtraumas, eventually reaching a volume large enough to cause significant and irreversible neurological symptoms. </p>
<p>Although evidence is mounting, it has yet to be fully proven that cavitation directly causes blast-induced traumatic brain injury. The hypothesis fits with <a href="https://pubmed.ncbi.nlm.nih.gov/27291520/">post-mortem analyses</a> of the brains of service members with a history of blast exposure. It also fits with the physics that link blast exposure to injury from tissue deformation. </p>
<p>Understanding the connection between blasts and cellular damage in the brain will help researchers develop better ways to protect against repetitive blast-induced traumatic brain injury.</p><img src="https://counter.theconversation.com/content/220267/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alice Lux Fawzi receives funding from the U. S. Office of Naval Research under the PANTHER Program.</span></em></p><p class="fine-print"><em><span>Christian Franck receives funding from the U.S. Office of Naval Research under the PANTHER program. </span></em></p>The people manning the guns are also at risk of injury from the force of the weapon.Alice Lux Fawzi, PANTHER Engineering Project Manager and Associate Director of the Center for Traumatic Brain Injury, University of Wisconsin-MadisonChristian Franck, Bjorn Borgen Professor of Mechanical Engineering and Director of the Center for Traumatic Brain Injury, University of Wisconsin-Madison, University of Wisconsin-MadisonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2241312024-02-26T17:24:36Z2024-02-26T17:24:36ZInsomnia: how chronic sleep problems can lead to a spiralling decline in mental health<figure><img src="https://images.theconversation.com/files/577722/original/file-20240224-24-su6ra5.jpg?ixlib=rb-1.1.0&rect=21%2C142%2C3629%2C2310&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/man-insomnia-cannot-sleep-hand-drawn-1965734296">APIMerah/Shutterstock</a></span></figcaption></figure><blockquote>
<p>I’ll often lie awake until three or four in the morning, before drifting off for just a few hours. Then comes the dreaded alarm clock. My mind and body are exhausted all the time – there’s always this knot of anxiety in my chest, doing away with any hope of a good night’s sleep.</p>
</blockquote>
<p>Simon* is a NHS mental health nurse who, like millions of people in the UK, suffers from insomnia: a sustained difficulty in initiating and maintaining sleep. His job is to support the recovery of people with severe mental illness, but his own sleep problems have had a profoundly negative impact on his mental health.</p>
<p>Most of us experience a bad night’s sleep from time to time, but can usually get back on track within a night or two. People suffering from insomnia, by contrast, have sleep problems that last for months or years at a time, taking a major toll on their health and wellbeing.</p>
<p>Around <a href="https://jcsm.aasm.org/doi/10.5664/jcsm.26929#:%7E:text=a%20cognitive%20system.-,CONCLUSION,%2C%20social%2C%20and%20physical%20domains.">a third</a> of people will experience insomnia at some point in their life, with women and older people more often affected. Nearly 40% of sufferers <a href="https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2772563">fail to recover within five years</a>. People with insomnia have an increased risk of diabetes, high blood pressure and <a href="https://www.sciencedirect.com/science/article/abs/pii/S1556407X22000182?via%3Dihub">cardiovascular disease</a>. Insomnia is also a major risk factor for <a href="https://onlinelibrary.wiley.com/doi/10.1111/jsr.13628">mental illness</a>, and often co-occurs with mood disorders such as depression and anxiety.</p>
<hr>
<p><em>Across the world, we’re seeing unprecedented levels of mental illness at all ages, from children to the very old – with huge costs to families, communities and economies. <a href="https://theconversation.com/uk/topics/tackling-the-mental-health-crisis-147216?utm_source=TCUK&utm_medium=ArticleTop&utm_campaign=MentalHealthSeries">In this series</a>, we investigate what’s causing this crisis, and report on the latest research to improve people’s mental health at all stages of life.</em></p>
<hr>
<p>Many different life events can increase your chances of sustained sleep deprivation. Both the financial burden and confinement arising from the COVID-19 pandemic were associated with <a href="https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-022-14048-1">greater risk</a> of insomnia, which is in turn likely to have led to a <a href="https://www.sciencedirect.com/science/article/pii/S1389945721004196?via%3Dihub">rise in mental health problems</a>.</p>
<p>And yet, very little is known about why and how a prolonged absence of sleep gives rise to mental illness. Our team at the University of York has pioneered research into whether sleep deprivation <a href="https://www.sciencedirect.com/science/article/pii/S1364661321000577">disrupts the brain’s ability to suppress intrusive memories</a> and distressing thoughts – classic symptoms of psychiatric disturbance. </p>
<p>It has also led us to ask whether it might one day be possible to treat mental illness while patients are sleeping – for example, by using sounds to normalise irregular patterns of brain activity during rapid eye movement (REM) sleep.</p>
<h2>Why are some people so badly affected?</h2>
<blockquote>
<p>They put their hand over my face so I couldn’t breathe. Now I can’t wear anything that covers my mouth or nose for fear of reliving [that experience]. Mask wearing was a big problem for me during the pandemic – and it was always worse when I slept badly. Just the sight of other people wearing masks could bring it all back.</p>
</blockquote>
<p>Helen* is a domestic abuse survivor who suffers from post-traumatic stress disorder (PTSD), a debilitating condition characterised by flashbacks, nightmares and severe anxiety. She told us her symptoms would always get worse after a bad night’s sleep – a pattern reported by other PTSD sufferers we spoke to.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/577724/original/file-20240224-26-m8ngfp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of woman in bed covering her face with her hands" src="https://images.theconversation.com/files/577724/original/file-20240224-26-m8ngfp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577724/original/file-20240224-26-m8ngfp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=439&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577724/original/file-20240224-26-m8ngfp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=439&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577724/original/file-20240224-26-m8ngfp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=439&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577724/original/file-20240224-26-m8ngfp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=552&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577724/original/file-20240224-26-m8ngfp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=552&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577724/original/file-20240224-26-m8ngfp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=552&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/insomnia-concept-young-woman-sitting-her-625713866">Randoms/Shutterstock</a></span>
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</figure>
<p>We can all sometimes encounter intrusive and unwanted thoughts, usually in response to reminders – for example, seeing a former partner and being reminded of an unpleasant breakup. While unsettling, these thoughts are infrequent, short-lived and, usually, quickly forgotten. This is in stark contrast to the highly lucid, distressing thoughts experienced by people with PTSD. Sufferers often engage in avoidant behaviour, such as not leaving home to reduce the likelihood of having to confront reminders of their trauma. </p>
<p>However, the symptoms of PTSD can also partly be explained by a breakdown of the brain mechanisms we rely on to push such intrusive thoughts out of conscious awareness. Because intrusive thoughts arise from unpleasant memories, another way people ward them off is by suppressing the offending content from their memory. But PTSD sufferers often <a href="https://journals.sagepub.com/doi/10.1177/0956797615569889">exhibit a deficit</a> in their ability to engage in this process of memory suppression, resulting in persistent unwanted patterns of thinking.</p>
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<img alt="" src="https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><strong><em>This article is part of Conversation Insights</em></strong>
<br><em>The Insights team generates <a href="https://theconversation.com/uk/topics/insights-series-71218">long-form journalism</a> derived from interdisciplinary research. The team is working with academics from different backgrounds who have been engaged in projects aimed at tackling societal and scientific challenges.</em></p>
<hr>
<p>And what if lack of sleep reduces our ability to suppress unwanted thoughts and memories? This could lead to a downward spiral of more persistent and frightening intrusive thoughts, severe anxiety, and chronic sleeplessness – culminating in psychiatric disturbance.</p>
<p>Although a <a href="https://www.nature.com/articles/nrn.2017.55">wealth of research</a> has shown that sleep deprivation leads to psychological instability, <a href="https://journals.sagepub.com/doi/10.1177/2167702620951511">our study</a> was the first study to examine how an inability to control intrusive thoughts might underpin this relationship. For this reason, we worked with young adults without a diagnosed mental health disorder, allowing us to determine how even healthy brain processes go awry when people do not get enough sleep.</p>
<h2>How sleep deprivation affects our brain</h2>
<p>Our group of young adults (aged 18–25) were asked to memorise face-image pairs, comprising a male or female face with a neutral expression next to a unique scene. They would memorise each pair over and over again, so that any face presented in isolation would serve as a powerful reminder of the scene it was paired with – in the same way a reminder of an unpleasant event in the real world can trigger a distressing thought.</p>
<p>The face-scene learning took place late in the evening – after which half the participants went to sleep in our laboratory, and the other half stayed awake for the entire night – watching movies, playing games and going for short walks outside. They could eat and drink, but psychological stimulants such as caffeine were strictly prohibited. We would wake anyone in this group who nodded off.</p>
<p>Next morning, all participants were shown the faces only, in random order, with the following instructions. If the face was inside a green frame, the participant should allow the associated scene to come into their mind. A red frame meant they should engage in memory suppression to block out the scene – in the same way we sometimes purge unwanted thoughts from our conscious experience.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/577966/original/file-20240226-24-8ldt9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Explanation of face-image sleep and memory suppression experiment." src="https://images.theconversation.com/files/577966/original/file-20240226-24-8ldt9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577966/original/file-20240226-24-8ldt9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=445&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577966/original/file-20240226-24-8ldt9l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=445&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577966/original/file-20240226-24-8ldt9l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=445&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577966/original/file-20240226-24-8ldt9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=560&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577966/original/file-20240226-24-8ldt9l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=560&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577966/original/file-20240226-24-8ldt9l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=560&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sleep and memory suppression experiment.</span>
<span class="attribution"><a class="source" href="https://www.epoc-york.com/research">Scott Cairney/University of York</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
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<p>Our sleep-deprived participants reported having more “intrusions” (failed memory suppression attempts) than those who had slept normally. And only well-rested participants got better at suppressing the unwanted memories over time. This suggests that sleeplessness does long-term harm to our ability to suppress intrusive memories and, hence, unwanted thoughts.</p>
<p>What’s going wrong inside a sleep-deprived person’s brain? To address this question, we <a href="https://www.biorxiv.org/content/10.1101/2023.11.07.565941v1">repeated our study</a>, but this time with participants undergoing <a href="https://www.ndcn.ox.ac.uk/divisions/fmrib/what-is-fmri/introduction-to-fmri">functional magnetic resonance imaging</a> (fMRI) – a powerful neuroimaging technique that allows us to determine which brain regions are engaged during particular cognitive operations (in this case, keeping intrusive memories at bay).</p>
<p>Memory suppression <a href="https://www.sciencedirect.com/science/article/pii/S1364661314000746?via%3Dihub">relies on a brain region</a> known as the right <a href="https://en.wikipedia.org/wiki/Dorsolateral_prefrontal_cortex">dorsolateral prefrontal cortex</a> (rDLPFC). When a reminder triggers retrieval of an unwanted memory, the rDLPFC inhibits activity in the brain’s memory processing centre, the <a href="https://en.wikipedia.org/wiki/Hippocampus">hippocampus</a>, to push that memory out of the person’s mind.</p>
<p>Our fMRI study showed that, when participants were attempting to suppress unwanted memories, activity in rDLPFC was reduced after a night of sleep deprivation relative to a night of restful sleep. Moreover, activity in the hippocampus was stronger after sleep deprivation than restful sleep, suggesting that a breakdown of control by rDLPFC had allowed unsolicited memory operations to emerge with impunity, opening the door to intrusive patterns of thinking.</p>
<h2>Can better sleep improve our mental health?</h2>
<p>REM sleep, discovered by <a href="https://www.science.org/doi/10.1126/science.118.3062.273">Eugene Aserinsky and Nathaniel Kleitman</a> in 1953, is a unique stage of sleep characterised by rapid movement of the eyes and a high propensity for vivid dreaming.</p>
<p>As the brain enters REM sleep, it undergoes dramatic changes that are thought to play an important role in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2890316/">regulating our mental health</a>. For example, levels of the neurotransmitter <a href="https://www.britannica.com/science/acetylcholine">acetylcholine</a>, which modulates the processing of disturbing memories, are markedly increased in REM sleep relative to other sleep stages, mirroring levels seen in wakefulness. Abnormalities of REM sleep are <a href="https://www.annualreviews.org/doi/10.1146/annurev-clinpsy-032813-153716">linked</a> to various psychiatric mood disorders including PTSD, and associated with the intense nightmares experienced following trauma.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-short-history-of-insomnia-and-how-we-became-obsessed-with-sleep-211729">A short history of insomnia and how we became obsessed with sleep</a>
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</em>
</p>
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<p>So, could the brain mechanisms that allow us to control intrusive memories be especially influenced by the amount of REM sleep we obtain over the course of a night? To investigate this, our fMRI study included <a href="https://pubmed.ncbi.nlm.nih.gov/31277862/">polysomnography</a> – a sleep monitoring technique that enabled us to identify when participants were in REM sleep, based on both their eye movement and discrete brainwave patterns.</p>
<p>Among our participants who slept, those who had more REM sleep showed stronger engagement of their rDLPFC when suppressing unwanted memories the next morning. This suggests REM sleep may indeed support mental health by restoring the brain systems that help to shield us from unwelcome thoughts.</p>
<h2>The emotional intensity of our memories</h2>
<p>When we think back to a traumatic or painful life event, we get a sense of the unpleasant feelings, such as sadness or anger, that accompanied the original experience. However, the intensity of these feelings is usually much reduced, allowing us to draw on past events without being consumed by negative emotions.</p>
<p>Suppressing unwanted thoughts has been shown to <a href="https://elifesciences.org/articles/71309">weaken the memories</a> that lead to them, meaning they are less likely to intrude into our consciousness in the future. This relates not only to the content of the memories (the “what, when and who”) but also <a href="https://www.jneurosci.org/content/37/27/6423.long">their emotional charge</a> – the intensity of the emotions we felt at the time. In other words, memory suppression helps us move on from prior adversity by gradually cleansing our memories of unpleasant experiences, and the negative emotions associated with them.</p>
<p>Conversely, failing to suppress an unwanted memory is likely to cause its emotional charge to linger, meaning that emotional responses to future reminders will remain more intense. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/577728/original/file-20240224-16-qbm7dc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of exhausted man in bed, suffering with insomnia" src="https://images.theconversation.com/files/577728/original/file-20240224-16-qbm7dc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577728/original/file-20240224-16-qbm7dc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=425&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577728/original/file-20240224-16-qbm7dc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=425&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577728/original/file-20240224-16-qbm7dc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=425&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577728/original/file-20240224-16-qbm7dc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=534&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577728/original/file-20240224-16-qbm7dc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=534&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577728/original/file-20240224-16-qbm7dc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=534&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/man-insomnia-cannot-sleep-hand-drawn-1819333274">APIMerah/Shutterstock</a></span>
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<p>We tested this by showing our participants scenes that were either emotionally negative (such as a car crash) or neutral (such as a forest). In the morning, after completing the memory retrieval and suppression task (with green and red-framed faces), participants were then asked to give intensity ratings for the negative and neutral scenes again.</p>
<p>Our findings were clear – and corroborated by further tests using an objective index of emotional arousal, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2695635/#:%7E:text=The%20skin%20conductance%20response%20(SCR)%20is%20an%20indirect%20measure%20of,emotional%20valence%20(Bradley%20et%20al.)">skin conductance responses</a>. Among participants who had slept, emotional responses to the suppressed negative scenes became less intense over time. But among the sleep-deprived, emotional ratings for negative scenes remained elevated, regardless of whether the scenes were suppressed or not. This suggests that a breakdown of memory suppression mechanisms after sleep loss prevented participants from being able to “deal with” these negative emotions.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/insomnia-and-mental-disorders-are-linked-but-exactly-how-is-still-a-mystery-212106">Insomnia and mental disorders are linked. But exactly how is still a mystery</a>
</strong>
</em>
</p>
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<p>In the context of psychiatric mood disorders that co-occur with chronic sleep disturbance, failure to suppress memories of emotionally disturbing events, together with an inability to reduce the unpleasant feelings embedded within those memories, could contribute to a strong tendency of mood-disordered individuals to focus on negative interpretations of the past.</p>
<p>Furthermore, anxiety arising from intrusive memories may also obstruct the sleep that is needed for recovery, leading to a vicious cycle of emotional dysregulation and sleeplessness.</p>
<h2>The importance of forgetting</h2>
<p>In the film Eternal Sunshine of the Spotless Mind (2004), the main characters have their memories of their turbulent relationship erased. Far from improving their quality of life, this leads to further complications, serving as a cautionary tale. </p>
<p>However, there are situations where aiding the forgetting process may help. For example, people who have experienced traumatic experiences can struggle to cope with unwanted memory intrusions. In these extreme cases, where the usual brain processes that allow for forgetting aren’t functioning properly, it could be beneficial to induce forgetting.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/07-QBnEkgXU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
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<p>Generally, forgetting is thought of as “bad”, with people worrying about forgetting where they put the car keys, or when their wedding anniversary is. But far from being a problem, this is how <a href="https://theconversation.com/why-forgetting-is-a-normal-function-of-memory-and-when-to-worry-223284">memory is supposed to work</a>. Sometimes, we want to just forget information that isn’t relevant to our daily lives, to prevent it from interfering with our goals. And sometimes, we want to forget embarrassing or emotionally scarring events.</p>
<p>Ultimately, the purpose of a functioning memory system is to make sensible and accurate decisions in the present, based on our past experience. The “adaptive” nature of forgetting allows us to get rid of irrelevant memories, making sure the memories that remain are as relevant to future decisions as possible. From this perspective, forgetting is as important as remembering. Simply put, forgetting is a feature of memory, not a bug.</p>
<p>While forgetting is a catch-all term we use for the loss of a memory, it isn’t a single process in the brain. Memories can be forgotten via active processes, such as memory suppression. But this can also happen via passive processes including “decay”, where the physical trace of a memory in the brain breaks down over time, or “interference”, where new memories that are similar to previous ones lead to confusion-impaired retrieval. For example, if you park your car in a new location in the supermarket you often visit, you might forget this new location because the usual place you park comes more readily to mind.</p>
<p>Forgetting is a complex phenomenon that unfolds over different timescales and via different processes, both while awake and asleep. While some memories can fragment, others are forgotten as a whole, so that all aspects of the memory are <a href="https://psycnet.apa.org/fulltext/2019-38883-001.html">no longer accessible</a>. </p>
<p>That forgetting is likely to occur during sleep has been underappreciated by psychologists, because research on sleep has largely focused on the role it plays in strengthening memories. But <a href="https://learnmem.cshlp.org/content/29/11/401.long">we</a> and <a href="https://www.jneurosci.org/content/37/3/464">other researchers</a> have recently reasoned that if forgetting is a fundamental part of a functioning memory system, then sleep should play as much of a role in forgetting as it does in retention.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/577727/original/file-20240224-16-ist89m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of sleep-deprived man in bed, covering his head with pillows." src="https://images.theconversation.com/files/577727/original/file-20240224-16-ist89m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577727/original/file-20240224-16-ist89m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=405&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577727/original/file-20240224-16-ist89m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=405&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577727/original/file-20240224-16-ist89m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=405&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577727/original/file-20240224-16-ist89m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=509&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577727/original/file-20240224-16-ist89m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=509&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577727/original/file-20240224-16-ist89m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=509&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/man-insomnia-cannot-sleep-hand-drawn-1936830988">APIMerah/Shutterstock</a></span>
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<p>Previous <a href="https://www.science.org/doi/10.1126/science.1179013?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed">research</a>, including <a href="https://www.cell.com/current-biology/fulltext/S0960-9822(18)30153-2">our own</a>, has shown that the presentation of specific sounds during sleep can boost memory. If you were to learn the location of a cat on a computer screen, and during learning we played a “meow” sound, the presentation of the same sound during sleep would lead to better location memory following sleep. This selective boosting of a specific memory during sleep is called “targeted memory reactivation”.</p>
<p>We have <a href="https://learnmem.cshlp.org/content/29/11/401.long">recently shown</a> that this technique can also be used to induce “selective forgetting”. We asked our participants to learn pairs of words or names before going to sleep. We used famous names, location and object words to allow participants to create vivid images in their minds for each pair, so they would be more likely to remember them after a night’s sleep.</p>
<p>But we also made sure the pairs overlapped by sharing one common word. When people learn these overlapping pairs, they compete against each other, and this competition can lead to <a href="https://psycnet.apa.org/record/1995-04358-001">forgetting</a> some of the words. We thought a similar forgetting effect might be seen by using targeted memory reactivation when participants were sleeping. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-forgetting-is-a-normal-function-of-memory-and-when-to-worry-223284">Why forgetting is a normal function of memory – and when to worry</a>
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<p>We found the presentation of the word during sleep caused reactivation and strengthening for one pair, but this had a disruptive effect for the other pair. This suggests we could use targeted memory reactivation to selectively strengthen and weaken memories during sleep, presuming we can create interference between two memories. This could be beneficial in the case of people whose brain processes aren’t functioning properly, not allowing them to “healthily forget” disturbing and intrusive memories.</p>
<p>Although such a treatment is still a long way off, our work raises the possibility of using sound cues during sleep – in combination with psychological techniques such as cognitive behavioural therapy – to decrease the crippling emotional grip a particular memory has on a patient.</p>
<h2>Modifying REM sleep to improve mental health</h2>
<p>Given the strong link between REM sleep and mental health disorders, REM sleep may represent a powerful therapeutic target for treating and preventing various psychiatric conditions. By delivering sounds in synchrony with naturally occurring brain rhythms, it is possible to modify patterns of brain activity that are associated with memory processing in REM sleep.</p>
<p>In <a href="https://academic.oup.com/sleep/article/44/4/zsaa227/5960115">one study</a>, we used a computerised algorithm to track rapidly emerging patterns of brain activity in real time while people were asleep (based on polysomnography data). When the algorithm detects the emergence of a particular brain rhythm, it delivers short bursts of sound to increase the intensity of that brain rhythm (akin to pushing a swing as it reaches the highest point of its cycle).</p>
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<p>We have showed this technique can be used to modify distinct brain rhythms in REM sleep. In future, such auditory stimulation could potentially provide a means of renormalising aberrant patterns of brain activity in REM sleep to treat psychiatric disturbance. For example, by integrating this technology with devices that are already available for people to monitor their sleep at home, the playing of particular sounds while someone is sleeping could provide a simple and cost-effective therapy for reducing mood disturbance.</p>
<p>However, this is a long way from being a reality, and many studies would be required to evaluate the feasibility of such an approach before it could be used as a therapeutic tool.</p>
<h2>Targeting sleep in psychiatric hospitals</h2>
<blockquote>
<p>High-risk patients undergo routine observations, sometimes as regularly as every ten minutes, all night and every night. Torches are shone into their rooms – to check they’re breathing – and there’s a lot of noise as doors are open and closed. It has a terrible impact on their sleep.</p>
</blockquote>
<p>Heather* is a consultant forensic psychiatrist who works on a secure mental health ward in the North of England. She describes how the ward regime (in this case, routine welfare checks on high-risk individuals performed throughout the night) impact on patients’ sleep.</p>
<p>A number of people with severe mental illness receive treatment in secure inpatient units. Although the goal of these psychiatric hospitals is to provide a therapeutic setting to support the improvement of mental health, many features of the inpatient environment, such as noise at night or the ward regime, can worsen patients’ sleep disturbances – intensifying the symptoms of their illness, including low mood, impulsivity and aggression.</p>
<p>At the same time, chronic sleeplessness often reduces patients’ engagement with psychological therapies (due to them sleeping in the day or lacking motivation), lengthening their admission and recovery time.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/577726/original/file-20240224-22-trso72.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of a man sitting up in bed, suffering with insomnia" src="https://images.theconversation.com/files/577726/original/file-20240224-22-trso72.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577726/original/file-20240224-22-trso72.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=426&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577726/original/file-20240224-22-trso72.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=426&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577726/original/file-20240224-22-trso72.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=426&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577726/original/file-20240224-22-trso72.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=535&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577726/original/file-20240224-22-trso72.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=535&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577726/original/file-20240224-22-trso72.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=535&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
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<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/man-insomnia-cannot-sleep-hand-drawn-1964955184">APIMerah/Shutterstock</a></span>
</figcaption>
</figure>
<p>In a recent international scoping review, we found that only a small number of non-pharmacological sleep interventions had been tested in psychiatric inpatient settings, despite <a href="https://www.medrxiv.org/content/10.1101/2023.03.03.23286483v1">clear evidence</a> that these improve both sleep and mental health outcomes.</p>
<p>New digital technologies can give a clear indication of patient welfare without the need for the noise and disruption Heather describes, providing an environment that is more conducive to healthy sleep. Future studies could test the potential for integrating these digital technologies with sleep-based therapies to speed up recovery times.</p>
<p>Achieving this goal is not only contingent on more research, but also on the capacity for carrying out scientific studies at scale. For example, all of the studies we have described were performed in tightly controlled laboratory environments, usually involving large and expensive pieces of equipment (for example, polysomnography systems). Though <a href="https://journals.sagepub.com/doi/10.1177/0956797619873344?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed">recent efforts have shown promise</a> in the feasibility of moving these techniques into people’s homes, much more work needs to be done outside of the lab before digitised, sleep-focused interventions for mental illness become a reality.</p>
<p>We envisage a future in which sleep is a routine target for reducing or preventing symptoms of mental illness, both in psychiatric inpatient settings and in people’s homes. Although there is much work still to do, sleep research is at an exciting juncture between bench and bedside, and offers a viable solution to the growing global burden of mental illness.</p>
<p><em>*Some names in this article have been changed to protect the anonymity of the interviewees.</em></p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=112&fit=crop&dpr=1 600w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=112&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=112&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=140&fit=crop&dpr=1 754w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=140&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=140&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p class="fine-print"><em><span>Scott Cairney has received funding from the Medical Research Council</span></em></p><p class="fine-print"><em><span>Aidan Horner receives funding from the Economic and Social Research Council and the Leverhulme Trust. </span></em></p>We envisage a future in which sleep is a routine target for reducing or preventing symptoms of mental illness, both in psychiatric settings and people’s homesScott Cairney, Associate Professor of Psychology, University of YorkAidan Horner, Associate Professor in Psychology and Neuroscience, University of YorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2225562024-02-14T13:25:12Z2024-02-14T13:25:12ZSeveral companies are testing brain implants – why is there so much attention swirling around Neuralink? Two professors unpack the ethical issues<figure><img src="https://images.theconversation.com/files/575184/original/file-20240213-26-hubky4.jpg?ixlib=rb-1.1.0&rect=0%2C6%2C2083%2C1427&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Brain-computer interfaces have the potential to transform some people's lives, but they raise a host of ethical issues, too.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/artificial-intelligence-brain-royalty-free-image/1195715936?phrase=brain+computer&adppopup=true">Andriy Onufriyenko/Moment via Getty Images</a></span></figcaption></figure><p><em>Putting a computer inside someone’s brain used to feel like the edge of science fiction. Today, <a href="https://www.gao.gov/products/gao-22-106118">it’s a reality</a>. Academic and commercial groups are testing “brain-computer interface” devices to enable people with disabilities to function more independently. Yet Elon Musk’s company, Neuralink, has put this technology front and center in debates about safety, ethics and neuroscience.</em> </p>
<p><em>In January 2024, Musk announced that Neuralink <a href="https://twitter.com/elonmusk/status/1752098683024220632">implanted its first chip</a> in a human subject’s brain. The Conversation reached out to two scholars at the University of Washington School of Medicine – <a href="https://depts.washington.edu/bhdept/nancy-s-jecker-phd-sheher">Nancy Jecker, a bioethicst</a>, and <a href="https://neurosurgery.uw.edu/bio/andrew-l-ko-md">Andrew Ko, a neurosurgeon</a> who implants brain chip devices – for their thoughts on the ethics of this new horizon in neuroscience.</em> </p>
<h2>How does a brain chip work?</h2>
<p>Neuralink’s coin-size device, called N1, is designed to enable patients to carry out actions just by concentrating on them, without moving their bodies.</p>
<p>Subjects in <a href="https://neuralink.com/pdfs/PRIME-Study-Brochure.pdf">the company’s PRIME study</a> – short for Precise Robotically Implanted Brain-Computer Interface – undergo surgery to place the device in a part of the brain that controls movement. The chip records and processes the brain’s electrical activity, then transmits this data to an external device, such as a phone or computer.</p>
<p>The external device “decodes” the patient’s brain activity, learning to associate certain patterns with the patient’s goal: moving a computer cursor up a screen, for example. Over time, the software can recognize a pattern of neural firing that consistently occurs while the participant is imagining that task, and then execute the task for the person. </p>
<p><a href="https://neuralink.com/#mission">Neuralink’s current trial</a> is focused on helping people with paralyzed limbs <a href="https://www.youtube.com/watch?v=z7o39CzHgug">control computers or smartphones</a>. Brain-computer interfaces, commonly called BCIs, can also be used to control devices <a href="https://doi.org/10.1080/17483107.2023.2211602">such as wheelchairs</a>.</p>
<h2>A few companies are testing BCIs. What’s different about Neuralink?</h2>
<p>Noninvasive devices positioned on the outside of a person’s head <a href="https://penntoday.upenn.edu/news/challenges-and-advances-brain-computer-interfaces">have been used in clinical trials for a long time</a>, but they have not received approval from the Food and Drug Administration for commercial development. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/575212/original/file-20240213-18-6c2r7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A young woman in a green shirt sits with a wired contraption on her head as four other people look on." src="https://images.theconversation.com/files/575212/original/file-20240213-18-6c2r7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/575212/original/file-20240213-18-6c2r7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/575212/original/file-20240213-18-6c2r7t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/575212/original/file-20240213-18-6c2r7t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/575212/original/file-20240213-18-6c2r7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/575212/original/file-20240213-18-6c2r7t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/575212/original/file-20240213-18-6c2r7t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A visitor experiences a BCI system during the 2023 China International Fair for Trade in Services in Beijing.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/visitor-experiences-domestic-brain-computer-interface-news-photo/1648339155?adppopup=true">Li Xin/Xinhua via Getty Images</a></span>
</figcaption>
</figure>
<p>There are other brain-computer devices, like Neuralink’s, that are <a href="https://doi.org/10.1038/d41586-024-00304-4">fully implanted and wireless</a>. However, <a href="https://neuralink.com/pdfs/PRIME-Study-Brochure.pdf">the N1 implant</a> combines more technologies in a single device: It can target individual neurons, record from thousands of sites in the brain and recharge its small battery wirelessly. These are important advances that could produce better outcomes.</p>
<h2>Why is Neuralink drawing criticism?</h2>
<p>Neuralink <a href="https://twitter.com/neuralink/status/1661857379460468736?lang=en">received FDA approval</a> for human trials in May 2023. Musk <a href="https://twitter.com/elonmusk/status/1752098683024220632">announced the company’s first human trial</a> on his social media platform, X – formerly Twitter – in January 2024.</p>
<p>Information about the implant, however, <a href="https://www.reuters.com/technology/want-details-elon-musks-brain-implant-trial-youll-have-ask-him-2024-02-02/">is scarce</a>, <a href="https://neuralink.com/pdfs/PRIME-Study-Brochure.pdf">aside from a brochure</a> aimed at recruiting trial subjects. Neuralink did not register at <a href="https://clinicaltrials.gov/">ClinicalTrials.gov</a>, as is <a href="https://clinicaltrials.gov/policy/faq">customary, and required by some academic journals</a>. </p>
<p>Some scientists are troubled by <a href="https://doi.org/10.1038/d41586-024-00304-4">this lack of transparency</a>. <a href="https://doi.org/10.1161/CIRCOUTCOMES.112.965798">Sharing information about clinical trials is important</a> because it helps other investigators learn about areas related to their research and can improve patient care. Academic journals can also be <a href="https://doi.org/10.1177/25152459211007467">biased toward positive results</a>, preventing researchers from learning from unsuccessful experiments. </p>
<p>Fellows at the Hastings Center, a bioethics think tank, have warned that Musk’s brand of “<a href="https://www.thehastingscenter.org/the-neuralink-patient-behind-the-musk/">science by press release, while increasingly common, is not science</a>.” They advise against relying on someone with a huge financial stake in a research outcome to function as the sole source of information.</p>
<p>When scientific research is funded by <a href="https://www.gao.gov/products/gao-23-105396">government agencies</a> or <a href="https://sciencephilanthropyalliance.org/">philanthropic groups</a>, its aim is to promote the public good. Neuralink, on the other hand, embodies <a href="https://www.propublica.org/article/what-is-private-equity">a private equity model</a>, which is <a href="https://thehill.com/opinion/healthcare/4365741-private-equity-is-buying-up-health-care-but-the-real-problem-is-why-doctors-are-selling/">becoming more common</a> <a href="https://www.press.jhu.edu/books/title/12719/ethically-challenged">in science</a>. Firms pooling funds from private investors to back science breakthroughs may strive to do good, but they also strive to maximize profits, which <a href="https://doi.org/10.1136/medethics-2021-107555">can conflict with patients’ best interests</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/575187/original/file-20240213-22-j0czv9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A phone screen shows a white page that says 'Elon Musk,' positioned below an abstract black design and the word 'NEURALINK.'" src="https://images.theconversation.com/files/575187/original/file-20240213-22-j0czv9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/575187/original/file-20240213-22-j0czv9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=366&fit=crop&dpr=1 600w, https://images.theconversation.com/files/575187/original/file-20240213-22-j0czv9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=366&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/575187/original/file-20240213-22-j0czv9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=366&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/575187/original/file-20240213-22-j0czv9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=460&fit=crop&dpr=1 754w, https://images.theconversation.com/files/575187/original/file-20240213-22-j0czv9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=460&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/575187/original/file-20240213-22-j0czv9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=460&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Neuralink’s first human implant was announced on Elon Musk’s social media platform X, formerly known as Twitter, in January 2024.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/elon-musk-account-on-twitter-and-neuralink-emblem-displayed-news-photo/1247138943?adppopup=true">NurPhoto via Getty Images</a></span>
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</figure>
<p>In 2022, the U.S. Department of Agriculture <a href="https://www.reuters.com/technology/musks-neuralink-faces-federal-probe-employee-backlash-over-animal-tests-2022-12-05/">investigated animal cruelty</a> at Neuralink, according to a Reuters report, after employees accused the company of rushing tests and botching procedures on test animals in a race for results. The agency’s inspection found no breaches, according to a letter from the USDA secretary to lawmakers, which Reuters reviewed. However, the secretary did note an “adverse surgical event” in 2019 that Neuralink had self-reported. </p>
<p>In a separate incident also reported by Reuters, the Department of Transportation <a href="https://www.reuters.com/technology/musk-brain-implant-company-violated-us-hazardous-material-transport-rules-2024-01-26/">fined Neuralink</a> for violating rules about transporting hazardous materials, including a flammable liquid. </p>
<h2>What other ethical issues does Neuralink’s trial raise?</h2>
<p>When brain-computer interfaces are used to help patients who suffer from disabling conditions function more independently, such as by helping them communicate or move about, this can profoundly improve their quality of life. In particular, it helps people recover a sense of their own agency or autonomy – one of <a href="https://depts.washington.edu/bhdept/ethics-medicine/bioethics-topics/articles/principles-bioethics">the key tenets</a> of medical ethics. </p>
<p>However well-intentioned, medical interventions can produce unintended consequences. With BCIs, scientists and ethicists are particularly concerned about the potential for <a href="https://theconversation.com/brain-computer-interfaces-could-allow-soldiers-to-control-weapons-with-their-thoughts-and-turn-off-their-fear-but-the-ethics-of-neurotechnology-lags-behind-the-science-194017">identity theft, password hacking and blackmail</a>. Given how the devices access users’ thoughts, there is also the possibility that <a href="https://doi.org/10.1057/s41599-023-02419-x">their autonomy</a> could be manipulated by third parties. </p>
<p>The ethics of medicine requires physicians to help patients, while minimizing potential harm. In addition to errors and privacy risks, scientists worry about <a href="https://doi.org/10.1038/d41586-024-00304-4">potential adverse effects</a> of a completely implanted device like Neuralink, since device components are not easily replaced after implantation.</p>
<p>When considering any invasive medical intervention, patients, providers and developers seek a balance between risk and benefit. At current levels of safety and reliability, the benefit of a permanent implant would have to be large to justify the uncertain risks.</p>
<h2>What’s next?</h2>
<p>For now, Neuralink’s trials are focused on patients with paralysis. Musk has said his ultimate goal for BCIs, however, is to help humanity – <a href="https://www.vox.com/future-perfect/2019/7/17/20697812/elon-musk-neuralink-ai-brain-implant-thread-robot">including healthy people</a> – “<a href="https://www.technologyreview.com/2020/08/30/1007786/elon-musks-neuralink-demo-update-neuroscience-theater/">keep pace” with artificial intelligence</a>.</p>
<p>This raises questions about another core tenet of medical ethics: <a href="https://link.springer.com/article/10.1007/s41465-018-0108-x">justice</a>. Some types of supercharged brain-computer synthesis could exacerbate social inequalities if only wealthy citizens have access to enhancements.</p>
<p>What is more immediately concerning, however, is the possibility that the device could be increasingly shown to be helpful for people with disabilities, but become unavailable due to loss of research funding. For patients whose access to a device is tied to a research study, the <a href="https://doi.org/10.1016/j.brs.2023.04.016">prospect of losing access after the study ends</a> can be devastating. This raises thorny questions about whether it is ever ethical to <a href="https://doi.org/10.1136/medethics-2016-103868">provide early access</a> to breakthrough medical interventions prior to their receiving full FDA approval.</p>
<p><a href="https://www.researchgate.net/publication/365700467_The_Unique_and_Practical_Advantages_of_Applying_A_Capability_Approach_to_Brain_Computer_Interface">Clear ethical and legal guidelines are needed</a> to ensure the benefits that stem from scientific innovations like Neuralink’s brain chip are balanced against patient safety and societal good.</p><img src="https://counter.theconversation.com/content/222556/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Brain-computer interface devices have the potential to boost users’ autonomy, especially for people who experience paralysis. But that comes with risks, as well.Nancy S. Jecker, Professor of Bioethics and Humanities, School of Medicine, University of WashingtonAndrew Ko, Assistant Professor of Neurological Surgery, School of Medicine, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2224582024-02-07T17:30:26Z2024-02-07T17:30:26ZThe brain is the most complicated object in the universe. This is the story of scientists’ quest to decode it – and read people’s minds<figure><img src="https://images.theconversation.com/files/573721/original/file-20240206-26-8guoy5.jpg?ixlib=rb-1.1.0&rect=299%2C119%2C3586%2C2874&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">HuthLab researchers (l-r) Alex Huth, Shailee Jain and Jerry Tang behind an fMRI scanner in the University of Texas's Biomedical Imaging Center.</span> <span class="attribution"><a class="source" href="https://cns.utexas.edu/news/podcast/brain-activity-decoder-can-reveal-stories-peoples-minds">Nolan Zunk/UT Austin</a></span></figcaption></figure><p>In the middle of 2023, a <a href="https://news.utexas.edu/2023/05/01/brain-activity-decoder-can-reveal-stories-in-peoples-minds/">study</a> conducted by the HuthLab at the University of Texas sent shockwaves through the realms of neuroscience and technology. For the first time, the thoughts and impressions of people unable to communicate with the outside world were translated into continuous natural language, using a combination of artificial intelligence (AI) and brain imaging technology.</p>
<p>This is the closest science has yet come to reading someone’s mind. While advances in neuroimaging over the past two decades have enabled non-responsive and minimally conscious patients to control a computer cursor with their brain, HuthLab’s research is a significant step closer towards accessing people’s actual thoughts. As Alexander Huth, the neuroscientist who co-led the research, <a href="https://www.nytimes.com/2023/05/01/science/ai-speech-language.html">told the New York Times</a>:</p>
<blockquote>
<p>This isn’t just a language stimulus. We’re getting at meaning – something about the idea of what’s happening. And the fact that’s possible is very exciting.</p>
</blockquote>
<p>Combining AI and brain-scanning technology, the team created a non-invasive brain decoder capable of <a href="https://www.biorxiv.org/content/10.1101/2022.09.29.509744v1">reconstructing continuous natural language</a> among people otherwise unable to communicate with the outside world. The development of such technology – and the parallel development of <a href="https://iopscience.iop.org/article/10.1088/2516-1091/ac23e6/meta">brain-controlled motor prosthetics</a> that enable paralysed patients to achieve some renewed mobility – holds tremendous prospects for people suffering from neurological diseases including <a href="https://www.ninds.nih.gov/health-information/disorders/locked-syndrome#:%7E:text=Locked%2Din%20syndrome%20is%20a,communicate%20with%20blinking%20eye%20movements">locked-in syndrome</a> and <a href="https://www.britannica.com/science/quadriplegia">quadriplegia</a>.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/9YLvDAqDJAE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Report on HuthLab’s ‘mind reading’ research by CBS Austin.</span></figcaption>
</figure>
<p>In the longer term, this could lead to wider public applications such as fitbit-style <a href="https://insider.fitt.co/a-50k-fitbit-for-your-brain/">health monitors for the brain</a> and <a href="https://link.springer.com/chapter/10.1007/978-3-319-94544-6_4">brain-controlled smartphones</a>. On January 29, Elon Musk <a href="https://twitter.com/elonmusk/status/1752098683024220632">announced</a> that his Neuralink tech startup had implanted a chip in a human brain for the first time. He had previously told followers that Neuralink’s first product, <a href="https://twitter.com/elonmusk/status/1752118131579867417">Telepathy</a>, would one day allow people to control their phones or computers “just by thinking”.</p>
<p>But alongside such technological developments come major <a href="https://theconversation.com/mri-scans-and-ai-technology-really-could-read-what-were-thinking-the-implications-are-terrifying-205503">ethical and legal concerns</a>. It’s not only privacy but the <a href="https://theconversation.com/freedom-of-thought-is-being-threatened-by-states-big-tech-and-even-ourselves-heres-what-we-can-do-to-protect-it-220266">very identity of people</a> that may be at risk. As we enter this new era of so-called <a href="https://www.newscientist.com/article/2408019-mind-reading-ai-can-translate-brainwaves-into-written-text/#:%7E:text=Using%20only%20a%20sensor%2Dfilled,person's%20thoughts%20into%20written%20words.">mind-reading technology</a>, we will also need to consider how to prevent its potential to help people being outweighed by its potential to do harm.</p>
<h2>Humanity’s greatest mapping challenge</h2>
<p>The brain is the <a href="https://today.uconn.edu/2018/03/complicated-object-universe/">most complicated object in the universe</a>. It contains more than 89 billion neurons, each connected to around 7,000 other neurons that send between ten and 100 signals every second. The development of AI was based on the brain and the <a href="https://theconversation.com/ai-will-soon-become-impossible-for-humans-to-comprehend-the-story-of-neural-networks-tells-us-why-199456">concept of neurons working together</a>. Now, the way AI works with deep learning is helping us understand much more clearly how the brain works.</p>
<p>By fully mapping the structure and function of a healthy human brain, we can determine with great precision what goes awry in diseases of the brain and mind. In 2009, <a href="https://humanconnectome.org/">the Human Connectome Project</a> was launched by the US National Institute of Health with the goal of building a map of the structure and function of a healthy human brain. Similar initiatives were launched in Europe in 2013 (<a href="http://www.humanbrainproject.eu/">the Human Brain Project</a>) and China in 2016 (<a href="https://www.sciencedirect.com/science/article/pii/S0896627316308005?via%3Dihub">the China Brain Project</a>).</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/Ud8gOmkxI7E?wmode=transparent&start=4" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Human Connectome video by BrainFacts.org.</span></figcaption>
</figure>
<p>This daunting endeavour may still take generations to complete – but the scientific ambition of mapping and reading people’s brains dates back more than two centuries. With the world having been circumnavigated many times over, Antarctica discovered and much of the planet charted, humanity was ready for a new (and even more complicated) mapping challenge – the human brain.</p>
<p>These efforts began in earnest in the late 18th century with the development of a systematic framework for scientists to ask how the brain and its regions produce psychological experiences – our thoughts, feelings and behaviour. One of the earliest attempts was <a href="https://www.britannica.com/topic/phrenology">phrenology</a>, pioneered by the Austrian physician and anatomist Franz Joseph Gall.</p>
<p>While this long-discredited science may now be best known for the <a href="https://artsci.case.edu/dittrick/online-exhibits/explore-the-artifacts/phrenology-bust-1850/">decorative busts</a> sold in flea markets, it was all the rage by the early 19th century. Gall and his assistant Johann Spurzheim suggested that the brain was organised along 35 psychological functions, each linked to a different underlying region.</p>
<hr>
<p><em>Across the world, we’re seeing unprecedented levels of mental illness at all ages, from children to the very old – with huge costs to families, communities and economies. <a href="https://theconversation.com/uk/topics/tackling-the-mental-health-crisis-147216?utm_source=TCUK&utm_medium=ArticleTop&utm_campaign=MentalHealthSeries">In this series</a>, we investigate what’s causing this crisis, and report on the latest research to improve people’s mental health at all stages of life.</em></p>
<hr>
<p>Just as you might start lifting dumbbells if you want larger biceps, phrenology argued that the more you use a particular psychological function, the more the brain region underlying it should grow – leading to a corresponding lump in your skull. <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1445-2197.2005.03426.x">According to Gall and Spurzheim</a>, some of these functions (including memory, love of offspring and the instinct to kill) were shared with animals, whereas others (such as wit, poetic ability and morality) were uniquely human.</p>
<p>Throughout the British empire and later in the US, phrenology was used to justify classism, colonialism, slavery and white supremacy. Queen Victoria had readings done on her children, but Napoleon Bonaparte was not a fan. When Gall moved to Paris in 1807 to perform much of his phrenological theorising, France’s emperor pronounced: “It is an ingenious fable which might seduce the <em>gens du monde</em>, but could not stand the scrutiny of the anatomist.”</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/572529/original/file-20240131-15-j86pu0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An old shop window with a large phrenology sign" src="https://images.theconversation.com/files/572529/original/file-20240131-15-j86pu0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/572529/original/file-20240131-15-j86pu0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=470&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572529/original/file-20240131-15-j86pu0.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=470&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572529/original/file-20240131-15-j86pu0.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=470&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572529/original/file-20240131-15-j86pu0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=591&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572529/original/file-20240131-15-j86pu0.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=591&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572529/original/file-20240131-15-j86pu0.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=591&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A phrenology shop in New Orleans in 1936.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Phrenology_Shop_in_New_Orleans_1936_by_Peter_Sekaer.jpg">Peter Sekaer/Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>In the 1860s, “locationist” views of how the brain worked made a comeback – though the scientists leading this research were keen to distinguish their theories from phrenology. French anatomist Paul Broca discovered a region of the left hemisphere responsible for producing speech – thanks in part to his patient, Louis Victor Leborgne, who at age 30 <a href="https://blogs.scientificamerican.com/literally-psyched/the-man-who-couldnt-speakand-how-he-revolutionized-psychology/">lost the ability to say anything</a> other than the syllable “tan”. Today, <a href="https://link.springer.com/referenceworkentry/10.1007/978-0-387-79948-3_655">Patient Tan</a> remains one of psychology’s most famous case studies, and <a href="https://www.hopkinsmedicine.org/news/media/releases/brocas_area_is_the_brains_scriptwriter_shaping_speech_study_finds">Broca’s area</a>, in the frontal cortex, is one of the most important language regions of the brain, playing a critical part in putting our thoughts into words.</p>
<p>Similarly, German neuroanatomist Korbinian Brodmann’s <a href="https://www.nature.com/articles/461884a#:%7E:text=Korbinian%20Brodmann's%20Localisation%20in%20the,cell%20type%20and%20laminar%20structure.">map of 52 distinct regions of the cerebral cortex</a>, first published in 1909, is still an important tool of contemporary neuroscience – and today’s neuroscientists continue to ask <a href="https://psu.pb.unizin.org/psych425/chapter/locationist-and-one-network-views-of-emotions-in-the-brain/">some of the same questions</a> as these pioneers: are our thoughts, feelings and behaviour produced by the collective action of the brain, or specific brain regions?</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/572528/original/file-20240131-15-6poatr.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of different areas of the brain" src="https://images.theconversation.com/files/572528/original/file-20240131-15-6poatr.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/572528/original/file-20240131-15-6poatr.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=763&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572528/original/file-20240131-15-6poatr.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=763&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572528/original/file-20240131-15-6poatr.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=763&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572528/original/file-20240131-15-6poatr.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=959&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572528/original/file-20240131-15-6poatr.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=959&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572528/original/file-20240131-15-6poatr.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=959&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Brodmann’s brain map.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Brodmann_areas.jpg">Vysha/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>In modern neuroscience studies, hi-tech scanning tools such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) allow researchers to map the brain by measuring changes in local blood flow that are linked to changes in local neural activity. This approach depends on <a href="https://academic.oup.com/brain/article-abstract/51/3/310/309681?redirectedFrom=fulltext">the findings</a> of American physiologist John Fulton almost a century ago. Fulton was treating Walter K, a 26-year-old sailor suffering from headaches and vision failure. When using his eyes after leaving a dark room, the patient sensed a noise in the back of his head, located over the visual cortex. This stronger pulse of activity was not replicated by other sensory inputs, for example when smelling tobacco or vanilla.</p>
<p>Over the remainder of the 20th century, this first observation of the link between local cerebral blood flow and brain function was built on by neuroscientists including American <a href="https://dm5migu4zj3pb.cloudfront.net/manuscripts/101000/101994/JCI48101994.pdf">Seymour Kety</a> and Swedish collaborators <a href="https://karger.com/ced/article-pdf/11/1/71/2335730/000047614.pdf">David Ingvar</a> and <a href="https://www.jstor.org/stable/24955823">Neils Lassen</a>. Their pioneering work paved the way for modern brain mapping, led by the ground-breaking work of <a href="https://www.braingate.org/about-braingate/">BrainGate</a> – a multidisciplinary research unit originating in the neuroscience department at Brown University in the US state of Rhode Island.</p>
<h2>The first clinical trial</h2>
<p>Prototype brain-computer interfaces (BCIs) record and decode a patient’s brain activity, translating it into actions that can be carried out by a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8979628/">neural cursor, prosthetic limb or powered exoskeleton</a>. The ultimate goal is wireless, non-invasive devices that help patients communicate and move with precision in the real world. AI is critical to this goal, and is <a href="https://www.cell.com/trends/cognitive-sciences/fulltext/S1364-6613(21)00096-6#secst0015">already being used to help BCI systems</a> produce finely controlled, rapid <a href="https://iopscience.iop.org/article/10.1088/1741-2552/abfaaa/meta">motor movements</a>.</p>
<p>In 2004, <a href="https://www.braingate.org/about-braingate/">BrainGate</a> began the first clinical trial using BCIs to enable patients with impaired motor systems (including spinal cord injuries, <a href="https://pubmed.ncbi.nlm.nih.gov/32809731/#:%7E:text=Brainstem%20infarction%20is%20an%20area,provide%20precise%20diagnosis%20and%20management.">brainstem infarctions</a>, locked-in syndrome and muscular dystrophy) control a computer cursor with their thoughts.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288776/original/file-20190820-170910-8bv1s7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><strong><em>This article is part of Conversation Insights</em></strong>
<br><em>The Insights team generates <a href="https://theconversation.com/uk/topics/insights-series-71218">long-form journalism</a> derived from interdisciplinary research. The team is working with academics from different backgrounds who have been engaged in projects aimed at tackling societal and scientific challenges.</em></p>
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<p><a href="https://www.patientcareonline.com/view/paralyzed-man-thinks-robotic-devices-motion">Patient MN</a>, a quadriplegic since being stabbed in the neck in 2001, was the trial’s first patient. After neuroscientist Leigh Hochberg’s team implanted electrodes over the hand-arm region of the patient’s primary motor cortex, they <a href="https://www.nature.com/articles/nature04970">reported</a> that Patient MN was able to open emails, draw figures using a paint program, and operate a television using a cursor. In addition, brain activity was linked to the patient’s prosthetic hand and robotic arm, enabling rudimentary actions including grasping and transporting an object. What’s more, these tasks could be done while the patient was having a conversation, suggesting they did not even demand the full concentration of the patient.</p>
<p>Other quadriplegic patients subsequently used BCI devices connected to multi-joint robotic arms to <a href="https://www.nature.com/articles/nature11076">pick up and drink from a cup</a> – and in <a href="https://journals.sagepub.com/doi/10.1177/1545968314554624">2015</a>, a patient with locked-in syndrome was shown operating a point-and-click keyboard five years after the device’s implantation. Advanced decoding algorithms saw their cursor control <a href="https://www.nature.com/articles/nm.3953">improve</a> such that patients went from typing <a href="https://www.science.org/doi/10.1126/scitranslmed.aac7328">24 characters per minute</a> in 2015 to <a href="https://elifesciences.org/articles/18554">39 characters per minute</a> two years later.</p>
<p>Also in 2017, BrainGate clinical trials reported the first evidence that BCIs could be used to <a href="https://www.sciencedirect.com/science/article/abs/pii/S0140673617306013?via%3Dihub">help patients regain movement</a> of their own limbs by bypassing the damaged portion of the spinal cord. One patient with a <a href="https://www.spinalinjury101.org/details/levels-of-injury">high-cervical</a> spinal cord injury was able to reach and grasp a cup eight years after sustaining his injury.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/cg5RO8Qv6mc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">BrainGate breakthrough video by Brown University.</span></figcaption>
</figure>
<p>Then in 2021, the Braingate team reported that quadriplegic patients were now using a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8218873/">wireless system in their own homes</a> to control a tablet computer – an important first step toward a future where BCI devices can help people move and communicate outside the confines of the hospital or laboratory. Furthermore, the researchers said they anticipate “significant advances and paradigm shifts in neural signal processing, decoding algorithms and control frameworks” in the quest to make such devices available to the wider public.</p>
<p>Beyond Braingate’s successes, another team led by American neurosurgeon Edward Chang <a href="https://www.nature.com/articles/s41586-023-06443-4">recently reported</a> using surgically implanted <a href="https://www.jneurosci.org/content/jneuro/39/22/4299.full.pdf">electrocorticogram</a> electrodes to create a “digital avatar” that could convey what a paralysed patient wants to say. With the help of AI, the BCI decoded muscle movements related to speech the patients were thinking in their minds (as opposed to decoding the actual semantic content).</p>
<p>Activity patterns emerging from the specific brain region that is critical for speech are the key focus for this type of BCI. One expert not involved in the research <a href="https://www.theguardian.com/society/2023/aug/23/paralysed-woman-able-to-speak-through-digital-avatar-for-first-time">told the Guardian</a>: “This is quite a jump from previous results. We’re at a tipping point.”</p>
<h2>A new era of ‘mind reading’ technology</h2>
<p>Brain activity has long been recorded by non-invasive imaging methods such as fMRI and electroencephalography (EEG). But having been primarily envisaged as a tool for diagnostics and monitoring, it is now also a core element of the latest neural communication and prosthetic devices.</p>
<p>A landmark moment came in 2012, when a team led by Canada-based neuroscientist <a href="https://www.youtube.com/watch?v=lvUvY_JrUgA">Adrian Owen</a> used neuroimaging to establish a <a href="https://cris.maastrichtuniversity.nl/ws/portalfiles/portal/75999517/Sorger_2012_Brain_computer_interfaces_for_communcication_with.pdf">line of communication</a> with people suffering from <a href="https://www.nhs.uk/conditions/disorders-of-consciousness/">disorders of consciousness</a>. Despite being behaviourally non-responsive and minimally conscious, these patients were able to answer yes-or-no questions just by using their minds. For patients unable to communicate via facial or eye movements (methods that had been available to locked-in patients for many years), this was a very promising evolution.</p>
<p>Now, a decade on, the <a href="https://www.biorxiv.org/content/10.1101/2022.09.29.509744v1.full">HuthLab research</a> at the University of Texas constitutes a paradigmatic shift in the evolution of communication-enabling neuroimaging systems.</p>
<p>In the study’s first stage, participants were placed in an fMRI scanner and their brain activity was recorded while they listened to 16 hours of podcasts (the model training dataset consisted of 82 five to 15-minute stories taken from the <a href="https://themoth.org/radio-hour">Moth Radio Hour</a> and <a href="https://www.nytimes.com/column/modern-love-podcast">Modern Love)</a>. This brain activity data was then linked to audio fragments the participants were listening to, in order to map what their brain activity patterns looked like when they had specific semantic content in their minds.</p>
<p>Next, the same participants were exposed to new audio fragments they had never heard before, or alternatively were asked to imagine a story. The decoder was then applied to this new set of brain activity data, to “reconstruct” the stories the participants had been listening to or imagining – with some <a href="https://www.biorxiv.org/content/10.1101/2022.09.29.509744v1.full">striking results</a>. For instance, when a patient was played this audio:</p>
<blockquote>
<p>I don’t have my driver’s licence yet and I just jumped out right when I needed to, and she says: ‘Well, why don’t you come back to my house and I’ll give you a ride?’ I say OK.</p>
</blockquote>
<p>… the decoder reconstructed it as follows:</p>
<blockquote>
<p>She is not ready – she has not even started to learn to drive, yet I had to push her out of the car. I said: ‘We will take her home now’ and she agreed.</p>
</blockquote>
<p>While there were also a considerable number of mistakes over the entirety of the trial, the reconstruction of continuous language solely on the base of brain activity patterns, including some exact word matches, is arguably the closest we have yet come to truly reading someone’s thoughts.</p>
<p>Whereas the brain’s capacity to produce motor intentions is shared across species, the ability to produce and perceive language is uniquely human. Thus, decoding actual semantic content from brain activity in regions used in language perception (primarily the <a href="https://www.ncbi.nlm.nih.gov/books/NBK11109/#:%7E:text=The%20association%20cortices%20include%20most,and%20the%20generation%20of%20behavior.">association</a> and <a href="https://www.ncbi.nlm.nih.gov/books/NBK499919/">prefrontal</a> regions of the brain’s cortex) seems more fundamental to what makes us human.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/572526/original/file-20240131-19-2rcmmf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Columns of text comparing actual words with those decoded by the HuthLab brain technology" src="https://images.theconversation.com/files/572526/original/file-20240131-19-2rcmmf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/572526/original/file-20240131-19-2rcmmf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=201&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572526/original/file-20240131-19-2rcmmf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=201&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572526/original/file-20240131-19-2rcmmf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=201&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572526/original/file-20240131-19-2rcmmf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=252&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572526/original/file-20240131-19-2rcmmf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=252&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572526/original/file-20240131-19-2rcmmf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=252&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Semantic examples from the HuthLab study.</span>
<span class="attribution"><span class="source">UT Austin</span></span>
</figcaption>
</figure>
<p>Also, the HuthLab study used non-invasive fMRI technology – a form of neuroimaging that measures oxygen levels of blood in the brain in order to make inferences on brain activity. The disadvantage of fMRI is that it can only take slow measurements of brain signals (typically, one brain volume every two or three seconds). The study overcame this by using <a href="https://en.wikipedia.org/wiki/Generative_artificial_intelligence">generative AI</a> language models (akin to ChatGPT) that predict the probability of word sequences, and thus what words are most likely to come next in someone’s thoughts.</p>
<p>The researchers also worked with patients watching silent short film clips. They demonstrated that the system could be used not only to decode semantic content entertained through auditive perception, but also through visual perception.</p>
<p>Importantly, they also explicitly addressed the potential threat to a person’s mental privacy posed by this kind of technology. Jerry Tang, one of the study’s lead researchers, <a href="https://cns.utexas.edu/news/podcast/brain-activity-decoder-can-reveal-stories-peoples-minds">stated</a>:</p>
<blockquote>
<p>We take very seriously the concerns that it could be used for bad purposes and have worked to avoid that. We want to make sure people only use these types of technologies when they want to and that it helps them.</p>
</blockquote>
<p>The very fact this semantic decoder has to be trained on each person separately, with their cooperation over a long period of time, constitutes a robust safeguard. In other words, one of the major hurdles in the development of language decoders – the fact they are not universally applicable – constitutes one of the strongest safeguards against privacy violations.</p>
<p>However, while there is no risk of a malevolent company being able to read the thoughts of a random person in the street any time soon, there are nonetheless important ethical, legal and data protection concerns that must be considered as this technology develops.</p>
<p>We have already seen the <a href="https://www.nytimes.com/2018/04/04/us/politics/cambridge-analytica-scandal-fallout.html">consequences</a> of unfettered corporate access to personal data and online behaviour. Although we are a long way off from neural data being collected and processed at such scale, it is important to consider burgeoning ethical questions in the early stages of technological progress.</p>
<h2>The ethical implications are immense</h2>
<p>Losing the ability to communicate is a <a href="https://www.tandfonline.com/doi/abs/10.1080/17483107.2022.2146217">deep cut to one’s sense of self</a>. Restoring this ability gives the patient greater control over their lives and their ability to navigate the world – but it could also give other entities, such as corporations, researchers and other third parties, an uncomfortable degree of insight into, or even control over, the lives of patients.</p>
<p>Even other types of intimate biological data, such as that about our genomes or our biometrics, do not come as close to approximating our private inner lives as neural data. The ethical implications of providing access to such data to scientific and corporate entities are potentially immense.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/572536/original/file-20240131-25-g07hqb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Text of UN resolution 51/3" src="https://images.theconversation.com/files/572536/original/file-20240131-25-g07hqb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/572536/original/file-20240131-25-g07hqb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=532&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572536/original/file-20240131-25-g07hqb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=532&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572536/original/file-20240131-25-g07hqb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=532&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572536/original/file-20240131-25-g07hqb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=668&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572536/original/file-20240131-25-g07hqb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=668&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572536/original/file-20240131-25-g07hqb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=668&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">UN resolution 51/3.</span>
<span class="attribution"><a class="source" href="https://documents-dds-ny.un.org/doc/UNDOC/GEN/G22/525/01/PDF/G2252501.pdf?OpenElement">UNHRC</a></span>
</figcaption>
</figure>
<p>This is reflected in <a href="https://www.ohchr.org/en/calls-for-input/2023/call-inputs-study-human-rights-council-advisory-committee-neurotechnology-and#:%7E:text=At%20its%20fifty%2Dfirst%20session,promotion%20and%20protection%20of%20all">Resolution 51/3</a> of the UN Human Rights Council, which commissioned a study on “the impact, opportunities and challenges of neurotechnology with regard to the promotion and protection of all human rights” in time for the council’s 57th session in September 2024. However, whether the introduction of novel human rights is warranted to address the challenges posed by neurotechnology remains a hotly debated issue among human rights experts and advocacy groups.</p>
<p>The <a href="https://neurorightsfoundation.org/mission">NeuroRights Foundation</a>, based at Columbia University in New York, argues that novel rights surrounding neurotechnologies will be needed for all humans to preserve their privacy, identity, and free will. The potential vulnerability of disabled patients makes this a particularly important problem. For example, Parkinson’s disease, a neurodegenerative disease that affects movement, is co-morbid with dementia, which affects the ability to reason and think clearly.</p>
<p>In line with this approach, <a href="https://spectrum.ieee.org/neurotech-neurorights">Chile was the first country</a> that adopted legislation to address the risks inherent to neurotechnology. It not only <a href="https://courier.unesco.org/en/articles/chile-pioneering-protection-neurorights">introduced a new constitutional right</a> to mental integrity, but is also in the process of adopting a bill that bans selling neurodata, and subjects all neurotech devices to be regulated as medical devices, even those intended for the general consumer. The proposed legislation recognises the intensely personal nature of neural data and considers it <a href="https://restofworld.org/2021/chile-neuro-rights/">akin to organ tissue</a> which cannot be bought or sold, only donated. But this legislation has also faced criticism, with legal scholars <a href="https://www.sciencedirect.com/science/article/abs/pii/S2589295921000059?casa_token=A9_9ASQthlMAAAAA:FXJiHZARnjPp6IjA7jHBqHzrHCAxoTY0s9um1nWWi9rE5so52ssahLBwwwkb5YTQGKR-sznGAg">questioning</a> the need for new rights and <a href="https://link.springer.com/article/10.1007/s12152-022-09504-z#Sec1">pointing out</a> that this regime could stifle beneficial BCI research for disabled patients.</p>
<p>While the legal action taken by Chile is the most impactful and far-reaching to date, <a href="https://spanish-presidency.consilium.europa.eu/en/news/leon-declaracion-european-neurotechnology-human-rights/">other countries</a> are considering following suit by updating existing laws to address the developments in neurotechnologies.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ybUnmQ05vX4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Chile’s pioneering neurotechnology regulation – report by Al Jazeera English.</span></figcaption>
</figure>
<p>One of the cornerstones of ethical research is the <a href="https://www.ncbi.nlm.nih.gov/books/NBK430827/#:%7E:text=Introduction,undergo%20the%20procedure%20or%20intervention.">principle of informed consent</a>. <a href="https://pubmed.ncbi.nlm.nih.gov/26497727/">Particular attention</a> must be paid to the capacity of paralysed patients and their family members to understand and consent to novel experimental therapies. Patients with a very limited ability to communicate may not be able to answer more extensive questions associated with the obtaining of informed consent, which is often more complex than a simple opt-in procedure. Also, not all potential risks and side-effects (both physical and mental) can be foreseen, making it difficult for physicians to adequately inform their patients.</p>
<p>At the same time, it is important <a href="https://link.springer.com/article/10.1007/s11948-015-9712-7">to keep in mind</a> that denying treatment to a patient whose only hope may be communicating through BCI presents a significant opportunity cost, such as a lifetime without communication, that may be very well greater than the costs of participation in experimental treatments. The appropriate balance to strike for clinicians and researchers will be challenging to determine.</p>
<p>In a burgeoning new era of big (brain) data, longstanding ethical concerns about the hacking, leaking, unauthorised use or commercial exploitation of personal data will be amplified in the case of sensitive data on a person’s thoughts or movements (as controlled through neuroprosthetics). Paralysed patients may be particularly vulnerable to neurodata theft given their reliance on caregivers, and increasingly, the BCI technologies themselves, to communicate and move around the world. Care must be taken to ensure that information disclosed by a BCI represents a patient’s true and consensual thoughts.</p>
<p>And while it is likely that the first advances in neurotech will be therapeutic in nature, such as for disabled and neurodivergent patients, future advances are likely to involve consumer applications such as <a href="https://bci.games/">entertainment</a>, as well as for <a href="https://theconversation.com/brain-computer-interfaces-could-allow-soldiers-to-control-weapons-with-their-thoughts-and-turn-off-their-fear-but-the-ethics-of-neurotechnology-lags-behind-the-science-194017#:%7E:text=For%20example%2C%20a%20soldier%20in,more%20rapid%20response%20to%20threats.">military and security</a> purposes. The growing availability of neurotechnology in a commercial context that is generally subject to far less regulation only amplifies these ethical and legal concerns.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/freedom-of-thought-is-being-threatened-by-states-big-tech-and-even-ourselves-heres-what-we-can-do-to-protect-it-220266">Freedom of thought is being threatened by states, big tech and even ourselves. Here’s what we can do to protect it</a>
</strong>
</em>
</p>
<hr>
<p>Data protection laws should be assessed on their ability to account for the new risks arising from increasing access to and collection of neurodata by organisations and entities of different types. Take the example – for the time being completely hypothetical – of using BCI to infer the thoughts of suspects in police interrogations.</p>
<p>One might say that BCI cannot be used in police interrogations as the error rate of misinterpreting a person’s neural data is currently unacceptably high, although accuracy could improve in the future. Or, one might say that BCI should never be used to “read” a person’s brain without their consent, regardless of the technology’s accuracy. Or, one might say that using BCI for interrogations is justified under certain extreme circumstances, such as when crucial information is needed to save someone’s life, and the suspect is refusing to cooperate.</p>
<p>Different people, societies, and cultures will disagree on where to draw the line. We are at an early stage of technological development and as we begin to uncover the great potential of BCI, both for therapeutic applications and beyond, the need to consider these ethical questions and their implications for legal action becomes more pressing.</p>
<h2>Decoding our neuro future</h2>
<p>This is a groundbreaking moment in our quest to understand the inner workings of our brains and minds. In the past year alone, neuroscientists have <a href="https://www.nature.com/articles/s41586-023-06094-5">reversed spinal disabilities</a>, translated MRI data into text to <a href="https://www.nature.com/articles/s41593-023-01304-%209.epdf">understand what someone is thinking</a>, and begun to <a href="https://twitter.com/neuralink/status/1661857379460468736?cxt=HHwWgMDSoeqejZAuAAAA">conduct clinical trials</a> to help people interact with objects using thoughts alone, something already seen in <a href="https://www.youtube.com/watch?v=Zcz-Hq1NP98">trials with monkeys</a> two years ago. Such developments could all lead to transformative impacts on people’s lives.</p>
<p>At the same time, it’s important to note that research such as the HuthLab study uses a very small sample, and that the training process for its semantic decoder is complex, time-consuming and expensive. Add to this the fact that fMRI, although non-invasive, is a non-wearable neuro-imaging technique, and it is clear these methods are not set to leave a strictly organised laboratory setting any time soon.</p>
<p>However, the HuthLab researchers <a href="https://cns.utexas.edu/news/podcast/brain-activity-decoder-can-reveal-stories-peoples-minds">suggest</a> that in time, fMRI could be replaced by functional near-infrared spectroscopy (fNRIS) which, by “measuring where there’s more or less blood flow in the brain at different points in time”, could give similar results to fMRI using a wearable device.</p>
<p>Certainly, the <a href="https://www.neurotech.com/investment-digest">exponential global investment</a> in the development of neurotechnologies such as this, by governments and private actors alike, shows that the world is eager to create accessible BCIs that are suited to function as medical devices, but also as commercial consumer goods. By the middle of 2021, the total investment in neurotechnology companies amounted to just over US$33 billion (around £26 billion).</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/M-slagG1OKE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Neuralink’s first human brain implant – report by Sky News.</span></figcaption>
</figure>
<p>One of the most high-profile companies is Musk’s <a href="https://neuralink.com/">Neuralink</a>. “Initial results show promising neuron spike detection,” Musk tweeted on January 29, of his neurotech startup’s <a href="https://www.npr.org/2024/01/30/1227850900/elon-musk-neuralink-implant-clinical-trial">first implanted chip in a human brain</a>. The implant is said to include 1,024 electrodes, yet is only slightly larger than the diameter of a red blood cell. <a href="https://twitter.com/neuralink/status/1716973591684653555">According to Neuralink</a>: “Its small size allows threads to be inserted with minimal damage to the [brain] cortex.”</p>
<p>While this wireless implant is currently being developed as a medical device, aiming at enhancing the quality of life for patients suffering from various neurological diseases (Neuralink’s clinical trial has enlisted people aged 22 and above living with quadriplegia), Musk <a href="https://twitter.com/elonmusk/status/1752119586470949056">stated on X-Twitter</a> that the ultimate aim is to create a device that “enables control of your phone or computer, and through them almost any device, just by thinking”.</p>
<p>Indeed, commercial neuro-imaging devices are already on the market. The <a href="https://www.spiedigitallibrary.org/journals/journal-of-biomedical-optics/volume-27/issue-07/074710/Kernel-Flow--a-high-channel-count-scalable-time-domain/10.1117/1.JBO.27.7.074710.full?webSyncID=cc96715c-8678-b272-ce9d-a31d41322dc9&sessionGUID=467762ac-1ce5-a61d-96e9-9042d3bc6d99&_ga=2.177093349.1194737154.1696754253-1060044912.1696754253&cm_mc_uid=86756417056816967542535&cm_mc_sid_50300000=84585101696754253521&SSO=1">Kernel Flow</a>, for example, is a commercially available, wearable headset that uses fNRIS technology to monitor brain activity. Another prominent player in commercial neuro-imaging, Emotiv, has developed <a href="https://www.emotiv.com/?campaignid=17057185126&adgroupid=138768698289&network=g&device=c&utm_term=emotiv%20eeg&utm_source=google&utm_medium=ppc&utm_content=644974459432&utm_campaign=Brand&hsa_acc=5401365090&hsa_cam=17057185126&hsa_grp=138768698289&hsa_ad=644974459432&hsa_src=g&hsa_tgt=kwd-343485221404&hsa_kw=emotiv%20eeg&hsa_mt=p&hsa_net=adwords&hsa_ver=3&gad=1&gclid=Cj0KCQjwpompBhDZARIsAFD_Fp9Pf4GC78tnxQw2h90QpHzibYCJenjkzWEsTArqRrXxCWkfdVmK1VkaAjeREALw_wcB">earpods incorporating EEG technology</a> that are able to monitor brain activity for signs of focus, attention and stress – with the stated ambition of boosting the wearer’s productivity at work.</p>
<p>While the era of big data has enabled increasingly personalised and complex approximations of people’s inner lives through our biometrics, genetics and online presence, nothing has been so powerful as to capture the inner workings of our minds – yet.</p>
<p>But as HuthLab’s research suggests, and Musk’s pronouncements claim, this may now not be so very far away. The dawn of a new era of brain-computer interfaces should be treated with great care and great respect – in acknowledgement of its immense potential to both help, and harm, our future generations.</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=112&fit=crop&dpr=1 600w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=112&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=112&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=140&fit=crop&dpr=1 754w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=140&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/313478/original/file-20200204-41481-1n8vco4.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=140&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
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</ul>
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<p class="fine-print"><em><span>Stephanie Sheir received funding from the EPSRC (grant number EP/V026518/1). </span></em></p><p class="fine-print"><em><span>Timo Istace receives funding from Fonds Wetenschappelijk Onderzoek Vlaanderen.</span></em></p><p class="fine-print"><em><span>Nicholas J. Kelley does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>As Elon Musk’s Neuralink begins inserting chips into human brains, we trace the history of ‘mind reading’ technology and assess the potential risks and rewardsNicholas J. Kelley, Assistant Professor in Social Psychology, University of SouthamptonStephanie Sheir, Research Associate, Trustworthy Autonomous Systems Hub, University of BristolTimo Istace, PhD Researcher in Neurotechnology and the Law, University of AntwerpLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2223732024-02-01T17:33:59Z2024-02-01T17:33:59ZThe first Neuralink brain implant signals a new phase for human-computer interaction<figure><img src="https://images.theconversation.com/files/572513/original/file-20240131-19-40gn6h.jpg?ixlib=rb-1.1.0&rect=26%2C0%2C5765%2C3994&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Neuralink is developing devices that enable direct communication between the human brain and computers.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/the-first-neuralink-brain-implant-signals-a-new-phase-for-human-computer-interaction" width="100%" height="400"></iframe>
<p>The <a href="https://www.reuters.com/technology/neuralink-implants-brain-chip-first-human-musk-says-2024-01-29">first human has received a Neuralink brain chip implant</a>, according to co-founder Elon Musk. The neurotechnology company has started its first human trial since <a href="https://www.reuters.com/science/elon-musks-neuralink-gets-us-fda-approval-human-clinical-study-brain-implants-2023-05-25/">receiving approval from the U.S. Food and Drug Administration</a> in 2023.</p>
<p>The trial’s focus is on an implant that could potentially allow people with <a href="https://neuralink.com/patient-registry/">severe physical disabilities to control digital devices using their thoughts</a>. The study involves <a href="https://www.reuters.com/technology/musks-neuralink-start-human-trials-brain-implant-2023-09-19/">implanting a brain chip</a> — called a brain-computer interface implant — in the region of the brain that controls movement intention. </p>
<p>Musk has said the patient who received the implant — <a href="https://www.cnet.com/health/medical/neuralinks-brain-chip-is-now-in-a-human-your-skull-is-safe-for-now/">fittingly named Telepathy</a> — is “recovering well” and that “initial results show promising neuron spike detection.” No other details about the trial have been provided yet.</p>
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<p>This development is more than just a technical milestone; it represents a major leap in potential human-computer interaction, raising important questions about the integration of advanced technology with the human body and mind.</p>
<h2>Neuralink’s mission</h2>
<p>Neuralink’s <a href="https://neuralink.com/">stated mission</a> is to “create a generalized brain interface to restore autonomy to those with unmet medical needs today and unlock human potential tomorrow.” This mission communicates two key approaches. </p>
<p>In the short term, the focus will be on individuals with medical needs. The long-term vision extends far beyond this, alluding to a goal of augmenting human potential. This suggests Neuralink envisions a future where its technology transcends medical use and becomes a tool for cognitive and sensory enhancement in the general population.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/z7o39CzHgug?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A video from Neuralink about its first human clinical trial.</span></figcaption>
</figure>
<p>The evolution of Neuralink presents a range of possible future scenarios. The first scenario envisions successful trials leading to adoption in niche markets, signifying a breakthrough but with restricted scope. </p>
<p>The second, more optimistic scenario, involves widespread acceptance after successful human trials, with the potential to revolutionize our interaction with technology. And the third — a more pessimistic view — considers the venture’s failure, driven by many societal, technological, legal and medical factors. </p>
<h2>The realistic scenario</h2>
<p>In the most realistic scenario, Neuralink is expected to achieve success by focusing on medical applications for individuals with severe disabilities. This targeted approach is likely to <a href="https://doi.org/10.3390/ijerph18179367">resonate with consumers in need of life-changing technologies</a>, which will drive early adoption within this specific demographic. </p>
<p>In this case, wider acceptance from the broader consumer base will hinge on various factors, including the technology’s <a href="https://doi.org/10.17705/1CAIS.05019">perceived usefulness</a>, <a href="https://doi.org/10.1016/j.ijmedinf.2015.12.010">privacy implications and the overall risk-benefit perception</a>.</p>
<p>Socially, Neuralink’s trajectory will be significantly influenced by <a href="https://doi.org/10.3390/philosophies5040031">public and ethical discussions</a>. Issues surrounding data security, long-term health implications and equitable access will likely dominate public discourse. </p>
<p>Widespread acceptance of Neuralink’s technology will depend on its medical efficacy and safety, combined with Neuralink’s ability to address ethical concerns and gain public trust.</p>
<h2>The optimistic scenario</h2>
<p>In the optimistic scenario, Neuralink’s technology transcends its initial medical applications and integrates into everyday life. This scenario envisions a future where the technology’s benefits are clearly demonstrated and recognized beyond its medical use, generating interest across various sectors of society.</p>
<p>Consumer interest in Neuralink would extend beyond those with medical needs, <a href="https://doi.org/10.1111/nyas.13040">driven by the appeal of enhanced cognitive abilities and sensory experiences</a>. As people become more familiar with the technology, concerns about invasiveness and data privacy may decrease, especially if Neuralink can provide robust safety and security assurances.</p>
<p>From a societal standpoint, the optimistic scenario sees Neuralink as a catalyst for positive change. The technology could bridge gaps in human potential, offering new ways of interaction and communication. </p>
<figure class="align-center ">
<img alt="A middle-aged man in a suit gestures while speaking" src="https://images.theconversation.com/files/572512/original/file-20240131-17-g477cl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/572512/original/file-20240131-17-g477cl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572512/original/file-20240131-17-g477cl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572512/original/file-20240131-17-g477cl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572512/original/file-20240131-17-g477cl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572512/original/file-20240131-17-g477cl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572512/original/file-20240131-17-g477cl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Elon Musk, co-founder of Neuralink, speaking at VivaTech, one of Europe’s largest tech and start-up fairs, in June 2023 in Paris, France.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>Although ethical concerns would still exist, the potential benefits in education, workforce productivity and overall quality of life could outweigh them. Regulatory bodies might adopt more accommodating policies, influenced by public enthusiasm and the technology’s track record in improving lives.</p>
<p>In this scenario, Neuralink becomes a symbol of human advancement, seamlessly integrating into daily life and opening new possibilities in human-machine interaction. </p>
<p>Its success would set a precedent for other technologies at the intersection of biology and technology, like <a href="https://doi.org/10.1016/bs.pmbts.2021.01.002">gene editing technologies </a> and <a href="https://doi.org/10.1101/cshperspect.a034306">bioelectronic medicine</a>, paving the way for a future where such integrations are the norm.</p>
<h2>The pessimistic scenario</h2>
<p>In the pessimistic scenario, Neuralink will face significant challenges that hinder its widespread adoption and success. <a href="https://rdcu.be/dxnKL">This scenario considers the possibility of the technology failing to meet the high expectations set for it</a>, either due to technological limitations, safety concerns or ethical dilemmas.</p>
<p>From a technological standpoint, the complexity of interfacing directly with the human brain could be more complex than anticipated, leading to underwhelming performance or reliability issues. </p>
<p><a href="https://doi.org/10.3390/philosophies5040031">Physical and psychological safety concerns</a> might also be more significant than initially thought, with potential long-term health implications that could deter both consumers and medical professionals.</p>
<p>The invasive nature of the technology and privacy concerns related to brain data could lead to widespread public apprehension. This skepticism could be compounded if early applications of the technology are perceived as benefiting only a select few, <a href="https://press.uchicago.edu/ucp/books/book/chicago/D/bo68657177.html">exacerbating social inequalities</a>.</p>
<p>Ethically, the prospect of brain-computer interfaces could raise questions about <a href="https://rdcu.be/dxstZ">human identity</a>, <a href="https://doi.org/10.1007/s10676-018-9466-4">autonomy and the nature of consciousness</a>. These concerns might fuel public opposition, leading to stringent regulatory restrictions and slowing down research and development.</p>
<p>In this scenario, Neuralink’s ambitious vision might be curtailed by a combination of technological hurdles, public mistrust, ethical controversies and regulatory challenges, ultimately leading to the project’s stagnation or decline.</p>
<p>While Neuralink presents numerous possibilities, its journey isn’t merely about technological advancement. The outcome of this venture holds key implications for the future of neural interfaces and our understanding of human capabilities, underscoring the need for a thoughtful approach to such innovation.</p><img src="https://counter.theconversation.com/content/222373/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Omar H. Fares does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Neuralink’s first human trial is more than just a technical milestone; it represents a major leap in potential human-computer interaction.Omar H. Fares, Lecturer in the Ted Rogers School of Retail Management, Toronto Metropolitan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2223742024-02-01T05:31:46Z2024-02-01T05:31:46ZAlzheimer’s may have once spread from person to person, but the risk of that happening today is incredibly low<figure><img src="https://images.theconversation.com/files/572598/original/file-20240131-25-8grmtv.jpg?ixlib=rb-1.1.0&rect=107%2C71%2C5883%2C3907&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/alzheimers-disease-mri-1025800153">Atthapon Raksthaput/Shutterstock</a></span></figcaption></figure><p>An article published this week in the prestigious journal <a href="https://www.nature.com/articles/s41591-023-02729-2">Nature Medicine</a> documents what is believed to be the first evidence that Alzheimer’s disease can be transmitted from person to person.</p>
<p>The finding arose from long-term follow up of patients who received human growth hormone (hGH) that was taken from brain tissue of deceased donors. </p>
<p>Preparations of donated hGH were used in medicine to treat a variety of conditions from 1959 onwards – including in Australia from the mid 60s. </p>
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<p>The practice stopped in 1985 when it was discovered around 200 patients worldwide who had received these donations went on to develop <a href="https://www.vdh.virginia.gov/epidemiology/epidemiology-fact-sheets/creutzfeldt-jakob-disease-cjd/">Creuztfeldt-Jakob disease</a> (CJD), which causes a rapidly progressive dementia. This is an otherwise extremely rare condition, affecting roughly one person in a million.</p>
<h2>What’s CJD got to do with Alzehimer’s?</h2>
<p>CJD is caused by prions: infective particles that are neither bacterial or viral, but consist of abnormally folded proteins that can be transmitted from cell to cell. </p>
<p>Other prion diseases include kuru, a dementia seen in New Guinea tribespeople caused by eating human tissue, scrapie (a disease of sheep) and variant CJD or bovine spongiform encephalopathy, otherwise known as mad cow disease. This raised <a href="https://en.wikipedia.org/wiki/United_Kingdom_BSE_outbreak">public health concerns</a> over the eating of beef products in the United Kingdom in the 1980s.</p>
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Read more:
<a href="https://theconversation.com/people-who-lived-in-the-uk-in-the-mad-cow-disease-years-may-now-be-able-to-give-blood-the-risk-of-vcjd-is-tiny-183521">People who lived in the UK in the 'mad cow disease' years may now be able to give blood. The risk of vCJD is tiny</a>
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<h2>Human growth hormone used to come from donated organs</h2>
<p>Human growth hormone (hGH) is produced in the brain by the pituitary gland. Treatments were originally prepared from purified human pituitary tissue.</p>
<p>But because the amount of hGH contained in a single gland is extremely small, any single dose given to any one patient could contain material from around <a href="https://www.cdc.gov/mmwr/preview/mmwrhtml/00000563.htm">16,000 donated glands</a>. </p>
<p>An average course of hGH treatment lasts around four years, so the chances of receiving contaminated material – even for a very rare condition such as CJD – became quite high for such people.</p>
<p>hGH is now manufactured synthetically in a laboratory, rather than from human tissue. So this particular mode of CJD transmission is no longer a risk. </p>
<figure class="align-center ">
<img alt="Scientist in a lab" src="https://images.theconversation.com/files/572600/original/file-20240131-25-f3bxeg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/572600/original/file-20240131-25-f3bxeg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572600/original/file-20240131-25-f3bxeg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572600/original/file-20240131-25-f3bxeg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572600/original/file-20240131-25-f3bxeg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572600/original/file-20240131-25-f3bxeg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572600/original/file-20240131-25-f3bxeg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Human growth hormone is now produced in a lab.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/woman-standing-in-front-of-the-sink-aelk4Tn0vlI">National Cancer Institute/Unsplash</a></span>
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<h2>What are the latest findings about Alzheimer’s disease?</h2>
<p>The Nature Medicine paper provides the first evidence that transmission of Alzheimer’s disease can occur via human-to-human transmission. </p>
<p>The authors examined the outcomes of people who received donated hGH until 1985. They found five such recipients had developed early-onset Alzheimer’s disease. </p>
<p>They considered other explanations for the findings but concluded donated hGH was the likely cause.</p>
<p>Given Alzheimer’s disease is a much more common illness than CJD, the authors presume those who received donated hGH before 1985 may be at higher risk of developing Alzheimer’s disease.</p>
<p>Alzheimer’s disease is caused by presence of two abnormally folded proteins: amyloid and tau. There is <a href="https://actaneurocomms.biomedcentral.com/articles/10.1186/s40478-017-0488-7">increasing evidence</a> these proteins spread in the brain in a <a href="https://pubmed.ncbi.nlm.nih.gov/8086126/">similar way to prion diseases</a>. So the mode of transmission the authors propose is certainly plausible. </p>
<p>However, given the amyloid protein deposits in the brain <a href="https://www.nia.nih.gov/news/estimates-amyloid-onset-may-predict-alzheimers-progression">at least 20 years</a> before clinical Alzheimer’s disease develops, there is likely to be a considerable time lag before cases that might arise from the receipt of donated hGH become evident.</p>
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Read more:
<a href="https://theconversation.com/size-of-brain-area-linked-with-cognitive-decline-even-in-people-with-no-other-warning-signs-of-alzheimers-disease-217729">Size of brain area linked with cognitive decline – even in people with no other warning signs of Alzheimer’s disease</a>
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<h2>When was this process used in Australia?</h2>
<p>In Australia, donated pituitary material <a href="https://www.health.gov.au/sites/default/files/documents/2022/07/the-cjd-review-final-report.pdf">was used</a> from 1967 to 1985 to treat people with short stature and infertility. </p>
<p><a href="https://www.health.gov.au/sites/default/files/documents/2022/07/the-cjd-review-final-report.pdf">More than 2,000 people</a> received such treatment. Four developed CJD, the last case identified in 1991. All four cases were likely linked to a single contaminated batch. </p>
<p>The risks of any other cases of CJD developing now in pituitary material recipients, so long after the occurrence of the last identified case in Australia, are <a href="https://www.mja.com.au/journal/2010/193/6/iatrogenic-creutzfeldt-jakob-disease-australia-time-amend-infection-control">considered to be</a> incredibly small.</p>
<p>Early-onset Alzheimer’s disease (defined as occurring before the age of 65) is uncommon, accounting for <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4356853/">around 5%</a> of all cases. Below the age of 50 it’s rare and likely to have a genetic contribution. </p>
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<img alt="Older man places his hands on his head" src="https://images.theconversation.com/files/572596/original/file-20240131-17-v3sclo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/572596/original/file-20240131-17-v3sclo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/572596/original/file-20240131-17-v3sclo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/572596/original/file-20240131-17-v3sclo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/572596/original/file-20240131-17-v3sclo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/572596/original/file-20240131-17-v3sclo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/572596/original/file-20240131-17-v3sclo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Early onset Alzheimer’s means it occurs before age 65.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/depressed-elderly-man-covers-his-face-1999395698">perfectlab/Shutterstock</a></span>
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<h2>The risk is very low – and you can’t ‘catch’ it like a virus</h2>
<p>The Nature Medicine paper identified five cases which were diagnosed in people aged 38 to 55. This is more than could be expected by chance, but still very low in comparison to the total number of patients treated worldwide. </p>
<p>Although the long “incubation period” of Alzheimer’s disease may mean more similar cases may be identified in the future, the absolute risk remains very low. The main scientific interest of the article lies in the fact it’s first to demonstrate that Alzheimer’s disease can be transmitted from person to person in a similar way to prion diseases, rather than in any public health risk.</p>
<p>The authors were keen to emphasise, as I will, that Alzheimer’s cannot be contracted via contact with or providing care to people with Alzheimer’s disease.</p>
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Read more:
<a href="https://theconversation.com/young-onset-alzheimers-can-be-diagnosed-from-as-early-as-30-and-the-symptoms-are-often-different-209561">Young-onset Alzheimer’s can be diagnosed from as early as 30 – and the symptoms are often different</a>
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<img src="https://counter.theconversation.com/content/222374/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steve Macfarlane is affiliated with HammondCare, a not-for-profit aged care provider. </span></em></p>Scientists have published the first evidence that Alzheimer’s can be transmitted from person to person. Patients received human growth hormone from the tissue of donated brains.Steve Macfarlane, Head of Clinical Services, Dementia Support Australia, & Associate Professor of Psychiatry, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2216842024-01-28T13:55:15Z2024-01-28T13:55:15ZThe contraceptive pill also affects the brain and the regulation of emotions<figure><img src="https://images.theconversation.com/files/570657/original/file-20231221-19-oxth15.jpg?ixlib=rb-1.1.0&rect=2%2C0%2C988%2C667&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Like natural hormones, known as endogenous hormones, the artificial hormones contained in the pill, known as exogenous hormones, can have effects on the brain.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Oral contraceptives, also known as birth control pills, are <a href="https://doi.org/10.18356/1bd58a10-en">used by more than 150 million women worldwide</a>. Approximately one-third of teenagers in <a href="https://www150.statcan.gc.ca/n1/en/pub/82-003-x/2015010/article/14222-eng.pdf">North America</a> and <a href="https://doi.org/10.1001/jamapsychiatry.2016.2387">Europe</a> use them, making them the most prescribed drug for teenagers.</p>
<p>It is well known that oral contraceptives have the power to alter a woman’s menstrual cycle. What’s less well known is that they can also have an effect on the brain, particularly in the regions that are important for regulating emotions.</p>
<p>As a doctoral student and professor of psychology at UQAM, we were interested in the impact of oral contraceptives on the brain regions involved in emotional processes. We published our <a href="https://doi.org/10.3389/fendo.2023.1228504">results in the scientific journal Frontiers in Endocrinology</a>.</p>
<h2>How does the pill work?</h2>
<p>There are several methods of hormonal contraception, but the most common type in North America is the contraceptive pill, more specifically, <a href="https://doi.org/10.1016/j.yfrne.2022.101040">combined oral contraceptives</a> (COCs). These are made up of two artificial hormones that simulate one of the types of estrogen (generally ethinyl estradiol) and progesterone.</p>
<p>Like natural hormones, known as endogenous hormones, the artificial hormones contained in the pill, known as exogenous hormones, <a href="https://doi.org/10.1016/j.yfrne.2022.101040">have an effect on the brain</a>. They bind to receptors in different areas and signal the brain to reduce the production of endogenous sex hormones. It is this phenomenon that leads to the cessation of menstrual cycles, preventing ovulation.</p>
<p>In other words, while using COCs, users’ bodies and brains are not exposed to the fluctuations in sex hormones typically seen in women with a natural cycle.</p>
<h2>The pill’s effects on the brain: neuroscience to the rescue!</h2>
<p>When they start taking COCs, teenage girls and women are informed of their different side effects, mainly physical (nausea, headaches, weight changes, breast tenderness). However, the fact that sex hormones affect the brain, particularly in areas important for regulating emotions, is not generally discussed.</p>
<p>Studies have associated the use of COCs with <a href="https://doi.org/10.1016/j.psyneuen.2018.02.019">poorer ability to regulate emotions</a> and a <a href="https://doi.org/10.1001/jamapsychiatry.2016.2387">higher risk of developing psychopathologies</a>.</p>
<p>In addition, women are more likely than men to suffer from <a href="https://doi.org/10.1016/j.jpsychires.2011.03.006">anxiety and chronic stress disorders</a>. Given the widespread use of COCs, it is important to gain a better understanding of their effects on the anatomy of the brain regions that are responsible for emotional regulation.</p>
<p>We therefore conducted a study to examine the effects of COCs on the anatomy of brain regions involved in emotional processes. We were interested in the effects associated with their current use, but also in the possibility of lasting effects, i.e. whether COCs could affect brain anatomy even after women stopped taking them.</p>
<p>To do this, we recruited four profiles of healthy individuals: women currently using COCs, women who had used COCs in the past, women who had never used any method of hormonal contraception, and men.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/567191/original/file-20231221-24-r2t5pd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="magnetic resonance imaging" src="https://images.theconversation.com/files/567191/original/file-20231221-24-r2t5pd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/567191/original/file-20231221-24-r2t5pd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/567191/original/file-20231221-24-r2t5pd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/567191/original/file-20231221-24-r2t5pd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/567191/original/file-20231221-24-r2t5pd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/567191/original/file-20231221-24-r2t5pd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/567191/original/file-20231221-24-r2t5pd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Magnetic resonance imaging (MRI) is used to analyze the morphology of certain regions of the brain.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Using brain imaging, we found that only women currently using COCs had a slightly thinner ventromedial prefrontal cortex than men. This part of the brain is known to be essential for regulating emotions such as fear. The scientific literature shows that <a href="https://doi.org/10.1073/pnas.0502441102">the thicker this region is, the better the emotional regulation will be</a>.</p>
<p>COCs could therefore alter emotional regulation in women. Although we have not directly tested the link between brain morphology and mental health, our team is currently investigating other aspects of the brain and mental health, which will allow us to better understand our anatomical findings.</p>
<h2>An effect associated with the dose, but that doesn’t last</h2>
<p>We tried to better understand what could explain the effect using COCs on this region of the brain. We discovered that it was associated with the dose of ethinyl estradiol. In fact, among COC users, only those using a low-dose COC (10-25 micrograms) – not a higher dose (30-35 micrograms) – were associated with a thinner ventromedial prefrontal cortex.</p>
<p>It may seem surprising that a lower dose was associated with a cerebral effect…</p>
<p>Given that all COCs reduce concentrations of endogenous sex hormones, we propose that estrogen receptors in this brain region may be insufficiently activated when low levels of endogenous estrogen are combined with a low intake of exogenous estrogen (ethinyl estradiol).</p>
<p>Conversely, higher doses of ethinyl estradiol could help to achieve adequate binding to estrogen receptors in the prefrontal cortex, simulating moderate to high activity similar to that of women with a natural menstrual cycle.</p>
<p>It is important to note that this lower grey matter thickness was specific to current COC use: women who had used COCs in the past showed no thinning compared to men. Our study therefore supports the reversibility of the impact of COCs on cerebral anatomy, in particular on the thickness of the ventromedial prefrontal cortex.</p>
<p>In other words, the use of COCs could affect brain anatomy, but in a reversible way.</p>
<h2>And now?</h2>
<p>Although our research has no direct clinical orientation, it is helping to advance our understanding of the anatomical effects associated with the use of COCs.</p>
<p>We are not calling for women to stop using their COCs: adopting such discourse would be both too hasty and alarming.</p>
<p>It’s also important to remember that the effects reported in our study appear to be reversible.</p>
<p>Our aim is to promote basic and clinical research, but also to increase scientific interest in women’s health, an area that is still understudied.</p><img src="https://counter.theconversation.com/content/221684/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alexandra Brouillard is a student member of the Research Centre of the Institut universitaire en santé mentale de Montréal. She holds a doctoral scholarship from the Canadian Institutes of Health Research.</span></em></p><p class="fine-print"><em><span>Marie-France Marin is a regular researcher at the Centre de recherche de l'Institut universitaire en santé mentale de Montréal, a professor in the Department of Psychology at the Université du Québec à Montréal and an associate professor in the Department of Psychiatry and Addictology at the Université de Montréal. She was supported by a salary grant from the Fonds de recherche du Québec - Santé (2018-2022) and currently holds a Canada Research Chair in Hormonal Modulation of Cognitive and Emotional Functions (2022-2027). The project discussed in the article is funded by the Canadian Institutes of Health Research and has received support from pilot project funds from the Research Centre of the Institut universitaire en santé mentale de Montréal and the Quebec Bioimaging Network.</span></em></p>Oral contraceptives modify the menstrual cycle. What’s less well known is that they also reach the brain, particularly the regions important for regulating emotions.Alexandra Brouillard, Doctorante en psychologie, Université du Québec à Montréal (UQAM)Marie-France Marin, Professor, Department of Psychology, Université du Québec à Montréal (UQAM)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2168592024-01-22T13:29:39Z2024-01-22T13:29:39ZWhy do people have different tastes in music? A music education expert explains why some songs are universally liked, while others aren’t<figure><img src="https://images.theconversation.com/files/566074/original/file-20231215-21-eo0769.jpg?ixlib=rb-1.1.0&rect=19%2C0%2C2121%2C1409&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The types of music you listen to can reflect your personality traits. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/group-of-young-friends-listening-to-music-with-royalty-free-image/1156897122?phrase=listening+to+music&adppopup=true">Smile/Stone via Getty Images</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
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<blockquote>
<p><strong>Why do we have a certain taste in music, different than others? – Shirya R., age 11</strong></p>
</blockquote>
<hr>
<p>When you turn on the radio, you might hear songs you like and other songs you just skip past. But even the songs you don’t like usually have some fans. Maybe you don’t like older music, but your parents or grandparents might love it <a href="https://theconversation.com/why-do-old-people-hate-new-music-123834">because they grew up</a> with it. It’s familiar and comfortable. When you’re older, you’ll likely return to music you love too.</p>
<p>As a <a href="https://scholar.google.com/citations?user=QXuOzQIAAAAJ&hl=en">music education professor</a> who teaches music psychology, I’ve spent a lot of time thinking about music preferences and how music weaves its way through people’s brains.</p>
<p>Some composers produce music with <a href="https://theconversation.com/burt-bacharach-mastered-the-art-of-the-perfect-pop-song-and-that-aint-easy-199660">cross-generational appeal</a>. Look at the song “True Colors,” which artists have remade time and time again. It was originally released in 1986 by <a href="https://www.youtube.com/watch?v=LPn0KFlbqX8">Cyndi Lauper</a>.</p>
<p>Ten years later, Disney World’s Epcot used it as part of a <a href="https://www.youtube.com/watch?v=yUm22pobGU4">pre-show video</a>. Ten years after that, it made its way to our ears again as part of the “Trolls” movie. Now, if you scour the internet, you’ll find lots of covers of this song.</p>
<p>How can this one song appeal to many different people over time, while other songs do not? Why do some people have wildly different tastes in music, even while certain songs can unite people from a variety of backgrounds and generations? </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/3JIpIsgHqV0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">‘True Colors’ from the movie ‘Trolls,’ starring Justin Timberlake and Anna Kendrick.</span></figcaption>
</figure>
<p>Researchers have looked at <a href="https://www.ucf.edu/pegasus/your-brain-on-music/">how music works in the brain</a>. They suggest people like music with unexpected twists and turns, which sometimes cause <a href="https://theconversation.com/why-do-only-some-people-get-skin-orgasms-from-listening-to-music-59719">pleasurable physical reactions</a> <a href="https://doi.org/10.3389/fnins.2020.565815">or chills</a>. This finding suggests that humans have created and listened to music over time <a href="https://doi.org/10.1093/scan/nsw009">because it is pleasurable or rewarding</a>.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/jyG8eWrpQ3Y?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">When you listen to music, you might get chills.</span></figcaption>
</figure>
<h2>Emotions and personality</h2>
<p>Some researchers suggest people experience emotions through music, or that they choose music based on what they want to feel. A <a href="https://doi.org/10.1037/a0022406">2011 study</a> suggests musical preference may reflect the emotions people feel when listening to music, regardless of the music’s style.</p>
<p>Some people respond to mellow and relaxing music. Others’ emotions are triggered by classical-style music. Still others emotionally react to singer-songwriter music like country, folk and some pop music. Preferences for certain types or styles of music might come from the time and place they’re first heard, or it may simply be specific to each person, regardless of what’s going on around them. </p>
<p>Though people might like certain music at one point in their lives, their music preferences change over time based on their lived experiences. When you’re struggling through a tough time, you might choose music that reflects what you wish was happening and <a href="https://doi.org/10.1007/s10824-022-09454-7">search for happy songs</a>. On the flip side, sometimes people <a href="https://doi.org/10.3389/fnhum.2015.00404">gravitate toward sad songs</a>. People want to move through grief, so they may search for songs that help them make sense of their emotions.</p>
<p>However, people’s choices don’t account for the whole picture. Musical taste goes <a href="https://doi.org/10.3389/fpsyg.2023.1062146">deeper than the music type or genre</a>. People who like pop or rock music don’t all like the same pop or rock music. </p>
<p>Studies on <a href="https://doi.org/10.1177/0956797618761659">personality and social media interaction</a> suggest your musical tastes can tell others what kind of personality you have. If someone knows what kind of music you like, that might tell them something about your personality. </p>
<p>Other <a href="https://doi.org/10.1037/pspp0000397">research suggests</a> your music preferences mirror your unique personality. So, people who already know you may be able to suggest music that you would like to hear.</p>
<p>For example, those who are more open might prefer mellow, sophisticated music like Billie Eilish’s “<a href="https://www.youtube.com/watch?v=cW8VLC9nnTo">What Was I Made For?</a>” or intense music like Imagine Dragons’ “<a href="https://www.youtube.com/watch?v=V5M2WZiAy6k">Natural</a>.”</p>
<p><a href="https://doi.org/10.1037/pspp0000397">The research found</a> extroverts may lean toward contemporary music. Agreeable people prefer unpretentious music, like Garrett Kato & Elina’s “<a href="https://www.youtube.com/watch?v=zgxNu8fBrgw">Never Alone</a>.” Conscientious people lean toward <a href="https://www.youtube.com/watch?v=0o5NTQMzNPo">unpretentious music</a> or intense music like Marshmello’s “<a href="https://www.youtube.com/watch?v=IYfejxVZ7lg">Power</a>.” People who are more anxious might prefer many different types of music.</p>
<p>People may like music by artists they like, rather than how the music sounds. Some prefer music from <a href="https://doi.org/10.1037/pspp0000293">artists who are like them</a>, especially when they can view their profiles on <a href="https://doi.org/10.1177/0956797618761659">social media</a>.</p>
<p>Why does knowing what music others like matter? Knowing about different people’s musical preferences and personalities <a href="https://www.youtube.com/watch?v=evVRxrOo5iw">can bridge gaps between people</a> with different personalities and identities. </p>
<h2>The music people stream</h2>
<p>A <a href="https://doi.org/10.1038/s41562-018-0508-z">study of 765 million songs streamed</a> by people worldwide revealed several reasons people listen to music. People’s preferences tended to change based on the time of day, their age and particular styles of music. Most people listened to more relaxing music at night but more intense music during the day. </p>
<p>Music streamed in Latin America often produced quicker physical and emotional reactions. Music streamed in Asia was usually relaxing. People who stay up later at night listened to less intense music. Depending on where participants lived, the length of the day also played a part in their music listening habits. In short, people’s environments and their individual moods shaped their preferences.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/TOhANADfR04?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Harmony in the Brain: Unraveling the Neuroscience of Music.</span></figcaption>
</figure>
<p>So, why do we have different tastes in music? People have complex personalities, and the music they like may be related to this. People’s brains work in unique ways as they process music. Some may have a physical reaction to certain music, while others may not. People may like music because a musician’s views might be like their own views. That said, some songs surprise, intrigue and entertain a wide variety of listeners, which makes them universally liked.</p>
<p>The bottom line? Each person is unique in many ways, and their musical tastes reflect that uniqueness.</p>
<hr>
<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/216859/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jane Kuehne does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Lots of factors can influence your music taste, from your age and where you’re from to the personality traits you have.Jane Kuehne, Associate Professor of Music Education, Auburn UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2213842024-01-21T12:59:06Z2024-01-21T12:59:06ZDietary fibre affects more than your colon: How the immune system, brain and overall health benefit too<figure><img src="https://images.theconversation.com/files/570412/original/file-20240119-19-bkynf2.jpg?ixlib=rb-1.1.0&rect=66%2C6%2C3923%2C2249&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Most people only consume about half of the recommended amount of dietary fibre, and it can negatively affect overall health.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/dietary-fibre-affects-more-than-your-colon-how-the-immune-system-brain-and-overall-health-benefit-too" width="100%" height="400"></iframe>
<p>There’s no shortage of advice about what to eat, including hype about the latest <a href="https://www.hsph.harvard.edu/nutritionsource/superfoods/">superfoods</a> that will help you <a href="https://www.npr.org/sections/thesalt/2015/04/11/398325030/eating-to-break-100-longevity-diet-tips-from-the-blue-zones">live to 100</a>, or about the newest <a href="https://food-guide.canada.ca/en/tips-for-healthy-eating/diets-food-trends/#section-2">restrictive diets</a> that claim to help you lose weight and look beautiful. As a researcher from the <a href="https://farncombe.mcmaster.ca/">Farncombe Family Digestive Health Research Institute</a>, I’m well aware that there is no universal “healthy diet” that will work for everyone. </p>
<p>However, most professionals would agree that a diet should be well balanced between the food groups, and it’s better to include more things like vegetables and <a href="https://doi.org/10.3390%2Fnu11081806">fermented foods</a> in your diet than restrict yourself unnecessarily. Eating foods that promote gut health improves your overall health too.</p>
<h2>Why is everyone so concerned about fibre?</h2>
<p>The importance of fibre has been known for decades. The late great surgeon and fibre researcher <a href="https://doi.org/10.1017/S0954422417000117">Denis Burkitt</a> once said, “If you pass small stools, you have to have large hospitals.” But dietary fibre does more than just help move your bowels. Fibre can be considered a <a href="https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/probiotics/faq-20058065">prebiotic nutrient</a>. </p>
<p>Prebiotics aren’t actively digested and absorbed, rather they are selectively used to promote the growth of a beneficial species of microbes in our gut. <a href="https://doi.org/10.3390%2Ffoods8030092">These microbes then help digest foods</a> for us so we can obtain more nutrients, promote gut barrier integrity and prevent the growth of harmful bacteria. </p>
<figure class="align-center ">
<img alt="High-fibre foods against the outline of intestines" src="https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570413/original/file-20240119-17-wpd6x9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Prebiotics aren’t actively digested and absorbed, rather they are selectively used to promote the growth of a beneficial species of microbes in our gut.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>Fibres can also have microbe-independent effects on our immune system when they <a href="https://doi.org/10.1111/bph.14871">interact directly with receptors expressed by our cells</a>. These beneficial effects may even help teach the immune system to be more tolerant and reduce inflammation.</p>
<h2>Getting enough dietary fibre?</h2>
<p>Probably not. The so-called <a href="https://doi.org/10.3390%2Fnu15122749">western diet</a> is low in fibre and filled with ultra-processed foods. The <a href="https://www.canada.ca/en/health-canada/services/nutrients/fibre.html">recommendation for daily fibre</a> is between <a href="https://doi.org/10.1038/s41575-020-00375-4">25-38 grams depending on factors like age, sex and activity level</a>. Most people consume about half of the recommendation, and it can negatively affect overall health. </p>
<p>Good sources of dietary fibre include whole grains, fruits and vegetables, beans and legumes, and nuts and seeds. There is a lot of emphasis on soluble fibres and less on insoluble fibres, but in reality, most foods will contain a mixture of both, and they each <a href="https://www.healthline.com/health/soluble-vs-insoluble-fiber%23risks">have their merits</a>. </p>
<p>High fibre snacks are also gaining popularity. With an estimated global value of US$7 billion in 2022, the <a href="https://www.precedenceresearch.com/prebiotic-ingredients-market#:%7E:text=The%2520global%2520prebiotic%2520ingredients%2520market,13.25%2525%2520from%25202022%2520to%25202030">value of the prebiotic ingredient market</a> is expected to triple by 2032.</p>
<h2>The benefits of dietary fibre</h2>
<figure class="align-right ">
<img alt="Diagram of a human with arrows linking brain and intestines" src="https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/570414/original/file-20240119-17-fwfmrl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fibre is associated with overall health and brain health through the gut-brain axis.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>There’s plenty of evidence supporting the benefits of dietary fibre. Fibre isn’t just associated with colon health; it’s associated with overall health and brain health through the <a href="https://my.clevelandclinic.org/health/body/the-gut-brain-connection">gut-brain axis</a>. Diets low in fibre have been associated with gastrointestinal disorders such as irritable bowel syndrome or inflammatory bowel disease. </p>
<p>On the other hand, consuming adequate fibre also <a href="https://doi.org/10.1038/s41575-020-00375-4">reduces the risk and mortality associated with cardiovascular diseases and obesity</a>. There are studies that show <a href="https://doi.org/10.3390/nu13072159">improvements of cognitive function with certain types of fibre</a>. </p>
<p>There are some gastrointestinal diseases, like Celiac disease, which are not typically associated with the benefits of dietary fibre. However, <a href="https://doi.org/10.1038/s41575-020-00375-4">there isn’t a consensus</a> to the specific type of fibre and dose that would be beneficial in treating most diseases.</p>
<h2>Not all fibre is good fibre</h2>
<p>Shockingly, not all fibre is good for you. Fibre is used as an umbrella term for indigestible plant polysaccharides, so there are many different types with varying fermentability, solubility and viscosity in the gut. </p>
<p>To make things more complex, <a href="https://doi.org/10.3389/fped.2020.620189">the source matters too</a>. Fibre from one plant isn’t the same as fibre from another plant. Additionally, the old proverb, “too much good is not good” rings true, where overconsumption of fibre supplements can cause symptoms such as constipation, bloating and gas. This is partly due to the differences in gut microbiomes that affect the ability to metabolize fibre to produce beneficial molecules like short-chain fatty acids. </p>
<p>In some cases, such as inflammatory bowel disease patients, lack of microbes with the capacity to digest fibre may allow intact fibres to <a href="https://doi.org/10.1053/j.gastro.2022.09.034">interact with intestinal cells directly and exert pro-inflammatory effects</a>. Recent evidence has even shown that excessively high consumption of soluble fibres, such as inulin, a common supplement, <a href="https://doi.org/10.1053/j.gastro.2023.10.012">can increase the risk of colon cancer development in an experimental animal model</a>.</p>
<h2>Part of a healthy diet</h2>
<p>Dietary fibre is an important part of a healthy diet that can promote both gut and overall health. Fibre helps you feel more satisfied after meals and helps to regulate your blood sugar and cholesterol. Do your best to consume fibre as part of your diet, and when needed, take only the dose of supplements as recommended. </p>
<p>Prebiotics promote the growth of gut microbes that can affect gut health and immunity in the context of many different diseases, although not all fibres are created equal. While fibre won’t cure illness, diet is a great addition to medicines and treatment strategies that can improve their efficacy.</p><img src="https://counter.theconversation.com/content/221384/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Wulczynski does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Fibre isn’t just associated with colon health; it’s associated with overall health and brain health through the gut-brain axis. But not all fibres are created equal.Mark Wulczynski, Medical Sciences PhD Candidate, McMaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2165502024-01-17T13:06:08Z2024-01-17T13:06:08ZIs our sense of fairness driven by selfishness? We’re studying the brain to find out<figure><img src="https://images.theconversation.com/files/569302/original/file-20240115-17-bhx103.jpg?ixlib=rb-1.1.0&rect=22%2C82%2C4954%2C3235&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Even kids know how to share.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/four-young-children-indoors-eating-pizza-15488146">Monkey Business Images</a></span></figcaption></figure><p>We’ve all been there. You’re dying to grab that last piece of cake on the table during an office meeting, but you are not alone. Perhaps you just cut off a small piece – leaving something behind for your colleagues, who do exactly the same thing. And so you all watch the piece of cake getting smaller and smaller – with nobody wanting to take the last piece.</p>
<p>Whenever we make choices in a social setting about how much we want to share with others we must navigate between <a href="https://theconversation.com/are-you-a-true-altruist-or-driven-by-self-interest-brain-scan-may-give-verdict-55545">our own selfish interests</a> and social norms for fairness. </p>
<p>But how fair are we truly? And under which circumstances do we offer others a fair share of the cake? Neuroscientific research has started revealing answers. Our own team used electric brain stimulation on 60 volunteers to figure out which parts of the brain were involved.</p>
<p>Humans have a strong preference for proactively conforming to social norms – even if there’s no punishment for not doing so. This has been extensively studied with economic games in which participants can decide how to distribute an amount of money between themselves and others. </p>
<p>Past research suggests that we simply <a href="https://academic.oup.com/qje/article-abstract/114/3/817/1848113?redirectedFrom=fulltext">prefer an equal split</a> between ourselves and others. Interestingly, this is not only in situations when we are disadvantaged compared to others (disadvantageous inequity) and may have something to gain from the sharing of resources, but also in cases when we are better off than others (advantageous inequity).</p>
<p>This ultimately suggests that our sense of fairness isn’t solely driven by a selfish desire to be better off than others. </p>
<p>What’s more, the preference for a fair share between ourselves and others <a href="https://www.nature.com/articles/s41562-016-0042#Abs1">emerges early in childhood</a>, suggesting it is to some extent hardwired. </p>
<p>The willingness to equally share resources with others persists even at the expense of sacrificing personal benefits. And when others give us an unfair share, we often feel <a href="https://www.science.org/doi/10.1126/science.1129156?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed">a strong urge to punish them</a> to protect our own interest. However, we typically do this even if it means that both of us end up with nothing in the end.</p>
<p>This raises the question of which psychological mechanisms support actions of different types of fairness decisions. Depending on whether we or the others find ourselves in a less favourable position, do the same psychological mechanisms drive our willingness to ensure a fair share with others? </p>
<h2>Understanding others</h2>
<p>One explanation for our tendency to be fair, even when we are better off than others, is that we understand other people’s perspectives. This might in fact encourage our willingness to sacrifice personal benefits for them. </p>
<p>Therefore, by taking the other’s perspective into account, we try to create a more equal environment by reducing inequality. Research has suggested that a small brain region facilitates our ability to navigate complex social environments: the right temporo-parietal junction (rTPJ).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/569784/original/file-20240117-27-4btohg.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Image pinpointing the temporoparietal junction." src="https://images.theconversation.com/files/569784/original/file-20240117-27-4btohg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/569784/original/file-20240117-27-4btohg.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/569784/original/file-20240117-27-4btohg.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/569784/original/file-20240117-27-4btohg.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/569784/original/file-20240117-27-4btohg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/569784/original/file-20240117-27-4btohg.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/569784/original/file-20240117-27-4btohg.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The temporoparietal junction.</span>
<span class="attribution"><span class="source">wikipedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The rTPJ plays a crucial role in understanding the thoughts and perspectives of others and might therefore help us make pro-social decisions. Given this, it has been proposed that this brain region <a href="https://www.cell.com/neuron/fulltext/S0896-6273(12)00487-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0896627312004874%3Fshowall%3Dtrue">contributes to our willingness to sacrifice personal benefits</a> for the sake of others. </p>
<p>But what about when we’re not better off than others? It may be that advantageous and disadvantageous inequity are based on different psychological mechanisms, potentially represented in different brain regions. </p>
<p>Some researchers suggest that the right lateral prefrontal cortex (rLPFC), a brain region which drives the <a href="https://www.nature.com/articles/nn.2933">rejection of unfair offers</a> and promotes the decision to punish social norm violators, might be involved. This is what ultimately makes us dislike being treated unfairly, particularly by those who are better off than us – unleashing <a href="https://www.science.org/doi/10.1126/science.1082976">negative emotions such as anger or envy</a>.</p>
<h2>Overcoming selfish motives</h2>
<p>Our recent research <a href="https://academic.oup.com/scan/article/18/1/nsad061/7335678?login=true">offers new insights</a> and reveals that the rTPJ and the rLPFC do indeed play different roles when it comes to fairness. </p>
<p>In our experiment, 60 participants made fairness decisions while undergoing a non-invasive type of electric brain stimulation called <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7867505/">transcranial alternating current stimulation</a> – applying a current to the scalp over a certain brain area to make it active. This enabled us to assess the involvement of specific brain regions. </p>
<p>Specifically, our study explored whether the same brain rhythms underlie the processes involved in making fairness decisions and take another’s perspective into account. We did that by electrically stimulating each brain area with different types of oscillations, or rhythms, and seeing how that affected people’s fairness decisions.</p>
<p>Our findings provide direct evidence that oscillations in the rTPJ play a crucial role for switching between one’s own and the other’s perspective. And when we do that, it ultimately helps us make proactive, fair decisions that also benefit others. A different type of underlying oscillation in the rLPFC instead seems to make people more utilitarian to overcome their less favourable position.</p>
<p>Future research will need to explore this link more deeply. But it does seem that fairness is not only driven by restricting one’s own selfish desires – which makes sense when you consider that cooperation is probably the single <a href="https://www.science.org/doi/10.1126/science.7466396">most important factor</a> in the evolutionary success of our species. Being selfish doesn’t always make us successful.</p>
<p>However, the process of trying to make fair decision is, as we all know, complex. The fact that there are different brain regions involved in doing so ultimately shows why this is the case.</p>
<p>We all have the capacity to be selfish. But we are also simply hardwired to balance our own perspective with understanding the minds of others – and empathising with them.</p><img src="https://counter.theconversation.com/content/216550/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Patricia Christian receives funding for her postdoctoral fellowship from the Wenner-Gren foundation. She receives no funding from an organisation or company that would benefit from this article. </span></em></p>The preference for fairness emerges early in childhood, suggesting it is to some extent hardwired.Patricia Christian, Postdoctoral Research Fellow at the Department of Clinical Neuroscience, Karolinska InstitutetLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2193202024-01-03T20:26:58Z2024-01-03T20:26:58ZAI is our ‘Promethean fire’: using it wisely means knowing its true nature – and our own minds<p>Future historians may well regard 2023 as a landmark in the advent of artificial intelligence (AI). But whether that future will prove <a href="https://a16z.com/ai-will-save-the-world/">utopian</a>, <a href="https://www.toolify.ai/ai-news/ais-apocalyptic-vision-24116">apocalyptic</a> or <a href="https://www.mckinsey.com/featured-insights/mckinsey-explainers/whats-the-future-of-generative-ai-an-early-view-in-15-charts">somewhere in between</a> is anyone’s guess. </p>
<p>In February, ChatGPT set the record as the fastest app to reach <a href="https://www.reuters.com/technology/chatgpt-sets-record-fastest-growing-user-base-analyst-note-2023-02-01/">100 million users</a>. It was followed by similar “large language” AI models from Google, Amazon, Meta and other big tech firms, which collectively look poised to transform education, healthcare and many other knowledge-intensive fields. </p>
<p>However, AI’s potential for harm was underscored in May by an <a href="https://www.safe.ai/statement-on-ai-risk">ominous statement</a> signed by leading researchers: </p>
<blockquote>
<p>Mitigating the risk of extinction from AI should be a global priority alongside other societal-scale risks such as pandemics and nuclear war. </p>
</blockquote>
<p>In November, responding to the growing concern about AI risk, 27 nations (including the UK, US, India, China and the European Union) pledged cooperation at an inaugural AI Safety Summit at Bletchley Park in England, to ensure the safe development of AI for the <a href="https://www.gov.uk/government/publications/ai-safety-summit-2023-the-bletchley-declaration/the-bletchley-declaration-by-countries-attending-the-ai-safety-summit-1-2-november-2023">benefit of all</a>. </p>
<p>To achieve this, researchers focus on <a href="https://en.wikipedia.org/wiki/AI_alignment">AI alignment</a> – that is, how to make sure AI models are consistent with human values, preferences and goals. But there’s a problem – AI’s so-called “<a href="https://www.technologyreview.com/2017/04/11/5113/the-dark-secret-at-the-heart-of-ai/">dark secret</a>”: large-scale models are so complex they are like a black box, impossible for anyone to fully understand. </p>
<h2>AI’s black box problem</h2>
<p>Although the transparency and explainability of AI systems are <a href="https://www.sciencedirect.com/science/article/pii/S1566253519308103?casa_token=eMCns9rVBmoAAAAA:ZozMhIZEA-Sd4IWnBBWRC6KmXV3THV4lqMYkWKf8-NrwaTxEKHqU2EAw4B-RZP0sCg0wazbml3o">important research goals</a>, such efforts seem unlikely to keep up with the frenetic pace of innovation. </p>
<p>The black box metaphor explains why people’s beliefs about AI are all over the map. Predictions range from utopia to extinction, and many even believe an artificial general intelligence (AGI) will soon <a href="https://www.science.org/content/article/if-ai-becomes-conscious-how-will-we-know">achieve sentience</a>. </p>
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Read more:
<a href="https://theconversation.com/a-year-of-chatgpt-5-ways-the-ai-marvel-has-changed-the-world-218805">A year of ChatGPT: 5 ways the AI marvel has changed the world</a>
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<p>But this uncertainty compounds the problem. AI alignment should be a two-way street: we must not only ensure AI models are consistent with human intentions, but also that our beliefs about AI are accurate. </p>
<p>This is because we are remarkably adept at creating futures that accord with those beliefs, even if we are unaware of them. </p>
<p>So-called “<a href="https://journals.sagepub.com/doi/abs/10.1111/1467-8721.ep10770698">expectancy effects</a>”, or self-fulfilling prophecies, are well known in psychology. And research has shown that manipulating users’ beliefs influences not just how they <a href="https://dl.acm.org/doi/pdf/10.1145/3529225">interact with AI</a>, but how AI <a href="https://dspace.mit.edu/bitstream/handle/1721.1/152316/NMI_AI_beholder_Final-Unformatted%5B85%5D.pdf?sequence=1&isAllowed=y">adapts to the user</a>. </p>
<p>In other words, how our beliefs (conscious or unconscious) affect AI can potentially increase the likelihood of any outcome, including catastrophic ones. </p>
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<strong>
Read more:
<a href="https://theconversation.com/how-ai-sees-the-world-what-happened-when-we-trained-a-deep-learning-model-to-identify-poverty-217586">How AI 'sees' the world – what happened when we trained a deep learning model to identify poverty</a>
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<h2>AI, computation, logic and arithmetic</h2>
<p>We need to probe more deeply to understand the basis of AI – like Alice in Wonderland, head down the rabbit hole and see where it takes us. </p>
<p>Firstly, what is AI? It runs on computers, and so is automated computation. From its origin as the “<a href="https://idp.springer.com/authorize/casa?redirect_uri=https://link.springer.com/content/pdf/10.1007/BF02478259.pdf&casa_token=Joxu9OnlEd4AAAAA:uCl-_FASTbvXSWBtZAt5bS24ZSRvOMsdufe1PG6PXY1TSdNoU0gL8a5j6I7lGmk4rqrSCbIqE0CQoxd9BnA">perceptron</a>” – an artificial neuron defined mathematically in 1943 by neurophysiologist <a href="https://en.wikipedia.org/wiki/Warren_Sturgis_McCulloch">Warren McCulloch</a> and logician <a href="https://en.wikipedia.org/wiki/Walter_Pitts">Walter Pitts</a> – AI has been intertwined with the cognitive sciences, neuroscience and computer science. </p>
<p>This convergence of <a href="https://www.cs.cmu.edu/afs/cs/academic/class/15883-f21/readings/churchland-1992-ch3.pdf">minds</a>, <a href="https://www.cell.com/fulltext/S0896-6273(17)30509-3">brains</a> and <a href="https://www.nature.com/articles/s41583-020-00395-8">machines</a> has led to the widely-held belief that, because AI is computation by machine, then natural intelligence (the mind) must be computation by the brain.</p>
<p>But what is computation? In the late 19th century, mathematicians <a href="https://en.wikipedia.org/wiki/Richard_Dedekind">Richard Dedekind</a> and <a href="https://en.wikipedia.org/wiki/Giuseppe_Peano">Giuseppe Peano</a> proposed a set of axioms which <a href="https://en.wikipedia.org/wiki/Peano_axioms">defined arithmetic in terms of logic</a>, and inspired attempts to ground all mathematics on a secure <a href="https://en.wikipedia.org/wiki/Hilbert%27s_program">formal basis</a>. </p>
<p>Although the logician <a href="https://en.wikipedia.org/wiki/Kurt_G%C3%B6del">Kurt Gödel</a> later proved this goal was <a href="https://en.wikipedia.org/wiki/G%C3%B6del%27s_incompleteness_theorems">unachievable</a>, his work was the starting point for mathematician (and code-breaker) <a href="https://en.wikipedia.org/wiki/Alan_Turing">Alan Turing</a>. His “<a href="https://en.wikipedia.org/wiki/Turing_machine">Turing machine</a>”, an abstract device capable of <a href="https://en.wikipedia.org/wiki/Church%E2%80%93Turing_thesis">universal computation</a>, is the foundation of computer science. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/forget-dystopian-scenarios-ai-is-pervasive-today-and-the-risks-are-often-hidden-218222">Forget dystopian scenarios – AI is pervasive today, and the risks are often hidden</a>
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<h2>Deep structure of perception</h2>
<p>So, computation is based on mathematical ideas that trace back to efforts to define arithmetic in logic. But our knowledge of arithmetic exists <a href="https://academic.oup.com/pq/article-abstract/68/273/717/4969397?redirectedFrom=PDF&casa_token=Z-7sIkFvtL0AAAAA:UOuTtFoVh9mpu6guxajdbe44O93oCe6PANK-Uz9yWL_0iX8lo-Lla-pPatTGINKxrAqB-MBpCtmts4cz">prior to logic</a>. If we want to understand the basis of AI, we need to go further and ask where arithmetic itself comes from. </p>
<p>My colleagues and I have recently shown that arithmetic is based on the “<a href="https://theconversation.com/arithmetic-has-a-biological-origin-its-an-expression-in-symbols-of-the-deep-structure-of-our-perception-211337">deep structure</a>” of perception. This structure is like coloured glasses that shape our perception in particular ways, so that our experience of the world is ordered and manageable. </p>
<p>Arithmetic consists of a set of elements (numbers) and operations (addition, multiplication) that combine pairs of elements to give another element. We asked: of all possibilities, why are numbers the elements, and addition and multiplication the operations? </p>
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Read more:
<a href="https://theconversation.com/arithmetic-has-a-biological-origin-its-an-expression-in-symbols-of-the-deep-structure-of-our-perception-211337">Arithmetic has a biological origin – it's an expression in symbols of the 'deep structure' of our perception</a>
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<p>We showed by <a href="https://psycnet.apa.org/fulltext/2023-84614-001.pdf?sr=1">mathematical proof</a> that when the deep structure of perception was assumed to limit the possibilities, arithmetic was the result. In other words, when our mind views the abstract world through the same “coloured glasses” that shape our experience of the physical world, it “sees” numbers and arithmetic. </p>
<p>Because arithmetic is the foundation for mathematics, the implication is that mathematics is a reflection of the mind – an expression in symbols of its fundamental nature and creativity. </p>
<p>Although the deep structure of perception is shared with other animals and so a product of evolution, only humans have invented mathematics. It is our most intimate creation – and by enabling the development of AI, perhaps our most consequential. </p>
<h2>A Copernican revolution of the mind</h2>
<p>Our account of <a href="https://theconversation.com/arithmetic-has-a-biological-origin-its-an-expression-in-symbols-of-the-deep-structure-of-our-perception-211337">arithmetic’s origin</a> is consistent with views of the 18th century philosopher Immanuel Kant. According to him, our knowledge of the world is structured by “pure intuitions” of space and time that exist prior to sense experience – analogous to the coloured glasses we can never remove.</p>
<p>Kant claimed his <a href="https://plato.stanford.edu/entries/kant/?rid=903123293s840c38">philosophy</a> was a “Copernican revolution of the mind”. In the same way ancient astronomers believed the Sun revolved around the Earth because they were unaware of the Earth’s motion, Kant argued, philosophers who believed all knowledge is derived from <a href="https://en.wikipedia.org/wiki/Empiricism">sense experience</a> (John Locke and David Hume, for example) overlooked how the mind shapes perception. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/ai-is-closer-than-ever-to-passing-the-turing-test-for-intelligence-what-happens-when-it-does-214721">AI is closer than ever to passing the Turing test for ‘intelligence’. What happens when it does?</a>
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<p>Although Kant’s views were shaped by the <a href="https://books.google.com/books?hl=en&lr=&id=cBtOFUg4tHAC&oi=fnd&pg=PR11&dq=Kant+and+the+exact+sciences&ots=2Uu_qCDZT-&sig=WKqrfULN9w5qL6TfVc63PEyP5RQ">natural sciences of his day</a>, they have proved <a href="https://www.cell.com/trends/cognitive-sciences/fulltext/S1364-6613(10)00216-0">influential in contemporary psychology</a>. </p>
<p>The recognition that arithmetic is a <a href="https://theconversation.com/arithmetic-has-a-biological-origin-its-an-expression-in-symbols-of-the-deep-structure-of-our-perception-211337">natural consequence of our perception</a>, and thus biologically based, suggests a similar Kantian shift in our understanding of computation.</p>
<p>Computation is not “outside” or separate from us in an abstract realm of mathematical truth, but inherent in our mind’s nature. The mind is more than computation; the brain is not a computer. Rather, computation – the basis for AI – is, like mathematics, a symbolic expression of the mind’s nature and creativity. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/computer-says-no-more-employers-are-using-ai-to-recruit-increasing-the-risk-of-discrimination-218598">'Computer says no’: more employers are using AI to recruit, increasing the risk of discrimination</a>
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<h2>Promethean fire</h2>
<p>What are the implications for AI? Firstly, AI is not a mind and will never become sentient. The idea we can transcend our biological nature and achieve immortality by uploading our minds to the cloud is only <a href="https://medium.com/iva-to/on-achieving-immortality-3ed1d567f7a2">fantasy</a>. </p>
<p>Yet if the principles of mind on which AI is based are shared by all humanity (and likely other living creatures as well), it may be possible to transcend the limitations of our individual minds.</p>
<p>Because computation is universal, we are free to simulate and create any outcome we choose in our increasingly connected virtual and physical worlds. In this way, AI is truly our <a href="https://www.japantimes.co.jp/editorials/2023/11/10/ai-global-governance/">Promethean fire</a>, a gift to humanity stolen from the gods as in <a href="https://en.wikipedia.org/wiki/Prometheus">Greek mythology</a>. </p>
<p>As a global civilisation, we are likely at a turning point. AI will not become sentient and decide to <a href="https://newatlas.com/technology/ai-danger-kill-everyone/">kill us all</a>. But we are very capable of “apocalypsing” ourselves with it – expectation can create reality. </p>
<p>Efforts to ensure AI alignment, safety and security are vitally important, but may not be enough if we lack awareness and collective wisdom. Like Alice, we need to wake up from the dream and recognise the reality and power of our minds.</p><img src="https://counter.theconversation.com/content/219320/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Randolph Grace receives funding from the Royal Society Te Apārangi, Marsden Fund</span></em></p>AI will not become sentient and decide to kill us all. But our own conscious or unconscious beliefs about AI can potentially increase the likelihood of any outcome, including catastrophic ones.Randolph Grace, Professor of Psychology, University of CanterburyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2183432024-01-01T20:35:27Z2024-01-01T20:35:27ZThink you’re good at multi-tasking? Here’s how your brain compensates – and how this changes with age<figure><img src="https://images.theconversation.com/files/565375/original/file-20231213-19-b09oz2.jpg?ixlib=rb-1.1.0&rect=0%2C197%2C2995%2C1800&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/unknown-persons-using-computer-indoors-nFLmPAf9dVc">Arlington Research/Unsplash</a></span></figcaption></figure><p>We’re all time-poor, so multi-tasking is seen as a necessity of modern living. We answer work emails while watching TV, make shopping lists in meetings and listen to podcasts when doing the dishes. We attempt to split our attention countless times a day when juggling both mundane and important tasks. </p>
<p>But doing two things at the same time isn’t always as productive or safe as focusing on one thing at a time.</p>
<p>The dilemma with multi-tasking is that when tasks become complex or energy-demanding, like driving a car while talking on the phone, our performance often drops on one or both. </p>
<p>Here’s why – and how our ability to multi-task changes as we age. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/women-arent-better-multitaskers-than-men-theyre-just-doing-more-work-121620">Women aren't better multitaskers than men – they're just doing more work</a>
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<h2>Doing more things, but less effectively</h2>
<p>The issue with multi-tasking at a brain level, is that two tasks performed at the same time often compete for common neural pathways – like two intersecting streams of traffic on a road. </p>
<p>In particular, the brain’s <a href="https://www.sciencedirect.com/science/article/pii/S0149763416300604">planning centres</a> in the frontal cortex (and connections to parieto-cerebellar system, among others) are needed for both motor and cognitive tasks. The more tasks rely on the same sensory system, like vision, the greater the interference. </p>
<figure class="align-center ">
<img alt="Regions of the brain" src="https://images.theconversation.com/files/566167/original/file-20231217-25-l8zcdp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566167/original/file-20231217-25-l8zcdp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566167/original/file-20231217-25-l8zcdp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566167/original/file-20231217-25-l8zcdp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566167/original/file-20231217-25-l8zcdp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=528&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566167/original/file-20231217-25-l8zcdp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=528&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566167/original/file-20231217-25-l8zcdp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=528&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The brain’s action planning centres are in the frontal cortex (blue), with reciprocal connections to parietal cortex (yellow) and the cerebellum (grey), among others.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/brain-areas-parts-functions-regions-anatomy-2159624763">grayjay/Shutterstock</a></span>
</figcaption>
</figure>
<p>This is why multi-tasking, such as talking on the phone, while driving can be risky. It <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6521777/#:%7E:text=These%20findings%20show%20that%20when,dangerous%20or%20risky%20behavioral%20responses.">takes longer</a> to react to critical events, such as a car braking suddenly, and you have a higher risk of missing critical signals, such as a red light. </p>
<p>The more involved the phone conversation, the <a href="https://www.researchgate.net/publication/7487625_Using_Mobile_Telephones_Cognitive_Workload_and_Attention_Resource_Allocation">higher the accident risk</a>, even when talking “hands-free”.</p>
<figure class="align-center ">
<img alt="Man drives car, while chatting" src="https://images.theconversation.com/files/565378/original/file-20231213-26-mh6h0x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565378/original/file-20231213-26-mh6h0x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565378/original/file-20231213-26-mh6h0x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565378/original/file-20231213-26-mh6h0x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565378/original/file-20231213-26-mh6h0x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565378/original/file-20231213-26-mh6h0x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565378/original/file-20231213-26-mh6h0x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Having a conversation while driving slows your reaction time.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-asian-man-drives-car-on-2291045823">GBJSTOCK/Shutterstock</a></span>
</figcaption>
</figure>
<p>Generally, the more skilled you are on a primary motor task, the better able you are to juggle another task at the same time. Skilled surgeons, for example, can <a href="https://journals.sagepub.com/doi/10.1177/1553350611430673">multitask more effectively</a> than residents, which is reassuring in a busy operating suite. </p>
<p>Highly automated skills and efficient brain processes mean <a href="https://www.sciencedirect.com/science/article/pii/S0304394023003671?via%3Dihub">greater</a> flexibility when multi-tasking. </p>
<h2>Adults are better at multi-tasking than kids</h2>
<p>Both brain capacity and experience endow adults with a greater capacity for multi-tasking compared with children. </p>
<p>You may have noticed that when you start thinking about a problem, you walk more slowly, and sometimes to a standstill if deep in thought. The ability to walk and think at the same time gets better over childhood and adolescence, as do other types of multi-tasking. </p>
<p>When <a href="https://www.tandfonline.com/doi/abs/10.1080/00222895.2020.1791038">children</a> do these two things at once, their walking speed and smoothness both wane, particularly when also doing a memory task (like recalling a sequence of numbers), verbal fluency task (like naming animals) or a fine-motor task (like buttoning up a shirt). Alternately, outside the lab, the cognitive task might fall by wayside as the motor goal takes precedence. </p>
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<strong>
Read more:
<a href="https://theconversation.com/tiktok-may-be-bad-for-privacy-but-is-it-also-harming-our-cognitive-abilities-203156">TikTok may be bad for privacy, but is it also harming our cognitive abilities?</a>
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<p>Brain maturation has a lot to do with these age differences. A larger prefrontal cortex helps share cognitive resources between tasks, thereby reducing the costs. This means better capacity to maintain performance at or near single-task levels. </p>
<p>The white matter tract that connects our two hemispheres (the corpus callosum) also takes a long time to fully mature, placing limits on how well children can walk around and do manual tasks (like texting on a phone) together. </p>
<p>For a child or adult with motor skill difficulties, or <a href="https://canchild.ca/en/diagnoses/developmental-coordination-disorder">developmental coordination disorder</a>, multi-tastking errors are more common. Simply standing still while solving a visual task (like judging which of two lines is longer) is hard. When walking, it takes <a href="https://pubmed.ncbi.nlm.nih.gov/27428781/">much longer</a> to complete a path if it also involves cognitive effort along the way. So you can imagine how difficult walking to school could be. </p>
<h2>What about as we approach older age?</h2>
<p>Older adults are more prone to multi-tasking errors. When walking, for example, adding another task generally means older adults walk much slower and with less fluid movement than younger adults. </p>
<p>These age differences are <a href="https://www.frontiersin.org/articles/10.3389/fneur.2018.00913/full">even more pronounced</a> when obstacles must be avoided or the path is winding or uneven. </p>
<figure class="align-center ">
<img alt="Two older people walk together" src="https://images.theconversation.com/files/565383/original/file-20231213-25-6cs3l0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565383/original/file-20231213-25-6cs3l0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565383/original/file-20231213-25-6cs3l0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565383/original/file-20231213-25-6cs3l0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565383/original/file-20231213-25-6cs3l0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565383/original/file-20231213-25-6cs3l0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565383/original/file-20231213-25-6cs3l0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Our ability to multi-task reduces with age.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/couple-elderly-people-walk-park-748880338">Shutterstock/Grizanda</a></span>
</figcaption>
</figure>
<p>Older adults <a href="https://www.tandfonline.com/doi/abs/10.1080/20445911.2022.2143788">tend to</a> enlist more of their prefrontal cortex when walking and, especially, when multi-tasking. This creates more interference when the same brain networks are also enlisted to perform a cognitive task. </p>
<p>These age differences in performance of <a href="https://journals.humankinetics.com/view/journals/japa/25/4/article-p671.xml">multi-tasking</a> might be more “compensatory” than anything else, allowing older adults more time and safety when negotiating events around them. </p>
<h2>Older people can practise and improve</h2>
<p>Testing multi-tasking capabilities can <a href="https://bmcgeriatr.biomedcentral.com/articles/10.1186/s12877-022-03271-5">tell clinicians</a> about an older patient’s risk of future falls better than an assessment of walking alone, even for healthy people living in the community. </p>
<p>Testing can be as simple as asking someone to walk a path while either mentally subtracting by sevens, carrying a cup and saucer, or balancing a ball on a tray. </p>
<p>Patients can then <a href="https://www.nature.com/articles/s41598-022-11489-x">practise and improve these abilities</a> by, for example, pedalling an exercise bike or walking on a treadmill while composing a poem, making a shopping list, or playing a word game. </p>
<p>The goal is for patients to be able to divide their attention more efficiently across two tasks and to ignore distractions, <a href="https://pubmed.ncbi.nlm.nih.gov/37772294/">improving</a> speed and balance.</p>
<h2>There are times when we do think better when moving</h2>
<p>Let’s not forget that a good walk can help unclutter our mind and promote creative thought. And, <a href="https://www.sciencedirect.com/science/article/pii/S0966636221001156?via%3Dihub">some research shows</a> walking can improve our ability to search and respond to visual events in the environment.</p>
<h2>But often, it’s better to focus on one thing at a time</h2>
<p>We often overlook the emotional and energy costs of multi-tasking when time-pressured. In many areas of life – home, work and school – we think it will save us time and energy. But the reality can be different. </p>
<p>Multi-tasking can sometimes sap our reserves and <a href="https://www.mdpi.com/2076-3425/9/11/290">create stress</a>, raising our cortisol levels, especially when we’re <a href="https://www.tandfonline.com/doi/full/10.1080/17437199.2022.2071323">time-pressured</a>. If such performance is sustained over long periods, it can leave you feeling fatigued or just plain empty. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-much-energy-do-we-expend-thinking-and-using-our-brain-197990">How much energy do we expend thinking and using our brain?</a>
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<p>Deep thinking is energy demanding by itself and so caution is sometimes warranted when acting at the same time – such as being immersed in deep thought while crossing a busy road, descending steep stairs, using power tools, or climbing a ladder. </p>
<p>So, pick a good time to ask someone a vexed question – perhaps not while they’re cutting vegetables with a sharp knife. Sometimes, it’s better to focus on one thing at a time.</p><img src="https://counter.theconversation.com/content/218343/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Wilson has received prior funding from the Australian Research Council (ARC), studying the motor and cognitive development of children. He currently receives funding from the Australian Automobile Association (AAA), studying hazard perception in older adult pedestrians. </span></em></p>Doing two things at the same time isn’t always as productive, healthy or safe as focusing on one thing at a time.Peter Wilson, Professor of Developmental Psychology, Australian Catholic UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2169802023-12-21T21:37:49Z2023-12-21T21:37:49ZThe Douglas-Bell Canada Brain Bank: a goldmine for research on brain diseases<figure><img src="https://images.theconversation.com/files/557356/original/file-20231005-26-rmh9lm.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4000%2C1508&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The experimental methods available today allow us to break the brain down into its elementary components in order to understand its functions and dysfunctions.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Human beings have always been fascinated by the brain. </p>
<p>Although scientific knowledge about this 1.3 kg of fragile substance embedded in our cranium has long been incomplete, dazzling technical breakthroughs made in recent years are now ushering in a Golden Age of molecular neuroscience. </p>
<p>These breakthroughs have been made possible partly thanks to brain banks, which preserve human brains in the best possible conditions for scientific research. Here in Montréal, we have one of the world’s largest such banks, the Douglas-Bell Canada Brain Bank (DBCBB), <a href="https://douglasbrainbank.ca">founded in 1980 at the Douglas Hospital</a>. </p>
<p>The DBCBB, which receives several brains each month, has collected over 3,600 specimens to date. Every year, its team processes dozens of tissue requests from scientists in Québec, Canada and abroad, preparing some 2,000 samples for research. </p>
<p>Over the past 40 years, these efforts have led to a considerable number of discoveries about different neurological and psychiatric diseases. </p>
<p>As a full professor in the department of psychiatry at McGill University, researcher at the Douglas Research Centre and director of the DBCBB since 2007, I work in close collaboration with <a href="https://www.mcgill.ca/psychiatry/gustavo-turecki">Dr. Gustavo Turecki</a>, co-director of the DBCBB and responsible for the component devoted to psychiatric illnesses and suicide.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/552153/original/file-20231004-17-mdh992.jpg?ixlib=rb-1.1.0&rect=14%2C2%2C1535%2C1231&q=45&auto=format&w=1000&fit=clip"><img alt="cerebral hemisphere" src="https://images.theconversation.com/files/552153/original/file-20231004-17-mdh992.jpg?ixlib=rb-1.1.0&rect=14%2C2%2C1535%2C1231&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/552153/original/file-20231004-17-mdh992.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=475&fit=crop&dpr=1 600w, https://images.theconversation.com/files/552153/original/file-20231004-17-mdh992.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=475&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/552153/original/file-20231004-17-mdh992.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=475&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/552153/original/file-20231004-17-mdh992.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=596&fit=crop&dpr=1 754w, https://images.theconversation.com/files/552153/original/file-20231004-17-mdh992.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=596&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/552153/original/file-20231004-17-mdh992.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=596&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Douglas-Bell Canada Brain Bank, which receives several brains each month, has collected over 3,600 specimens to date.</span>
<span class="attribution"><span class="source">(Naguib Mechawar)</span>, <span class="license">Fourni par l'auteur</span></span>
</figcaption>
</figure>
<h2>A brief history of research on the human brain</h2>
<p>Scientists only began to identify the microscopic elements that make up the human brain in the second half of the 19th century. </p>
<p>That was when brains were preserved for the first time in formalin, a solution that preserves biological tissue so that it can be handled more easily and stored over a longer term.</p>
<p>At the same time, precision instruments and protocols were being developed that made it possible to examine the microscopic characteristics of nervous tissue.</p>
<p>Until the middle of the 20th century, researchers were mainly satisfied with preserving the brains of patients, taken during autopsies, so they could use them to identify possible macroscopic or microscopic changes linked to either neurological or psychiatric symptoms.</p>
<p>This is in fact what the German neurologist Alois Alzheimer did when he analyzed the brain of one of his patients suffering from dementia. In 1906, he described, for the first time, the microscopic lesions which characterize the disease that now bears his name.</p>
<p>Until the end of the 1970s, numerous collections of brain specimens preserved in formalin were built in hospital environments, a bit like the cabinets of curiosities of olden days.</p>
<p>Towards the end of the 20th century, new experimental approaches were developed allowing the high-resolution analysis of cells and molecules within biological tissues.</p>
<p>It then became necessary to collect and preserve human brains, obtained with the consent of the individual or his or her family, in conditions compatible with modern scientific techniques.</p>
<p>Researchers began freezing one of the cerebral hemispheres in order to measure its various molecular components. The other hemisphere was preserved in formalin to be used for macroscopic and microscopic anatomical studies.</p>
<p>This was the context in which the Douglas-Bell Canada Brain Bank was created.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/552154/original/file-20231004-25-z5k7jp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="The DBCBB premises" src="https://images.theconversation.com/files/552154/original/file-20231004-25-z5k7jp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/552154/original/file-20231004-25-z5k7jp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/552154/original/file-20231004-25-z5k7jp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/552154/original/file-20231004-25-z5k7jp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/552154/original/file-20231004-25-z5k7jp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/552154/original/file-20231004-25-z5k7jp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/552154/original/file-20231004-25-z5k7jp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Montréal is home to one of the world’s largest brain banks, the Douglas-Bell Canada Brain Bank, which was founded in 1980 at the Douglas Hospital.</span>
<span class="attribution"><span class="source">(Naguib Mechawar)</span>, <span class="license">Fourni par l'auteur</span></span>
</figcaption>
</figure>
<h2>New experimental approaches are yielding results</h2>
<p>Leading researchers from many universities around the world now use DBCBB samples to advance their research. This, of course, includes a number of teams in Québec.</p>
<p>For example, with his team from the Douglas Research Centre, which is affiliated with McGill University, <a href="https://douglas.research.mcgill.ca/judes-poirier/">Judes Poirier</a> discovered that the APOE4 gene is a <a href="https://doi.org/10.1016/0140-6736(93)91705-Q">risk factor for Alzheimer’s disease</a>. More recently, the team of <a href="https://crhmr.ciusss-estmtl.gouv.qc.ca/en/researcher/gilbert-bernier">Gilbert Bernier</a>, professor in the department of neuroscience at Université de Montréal, discovered that the lesions characteristic of this disease are associated with <a href="https://doi.org/10.1038/s41598-018-37444-3">abnormal expression of the BMI1 gene</a>.</p>
<p>With regard to psychiatric illnesses, and more specifically depression, major progress has been made recently by the <a href="https://douglas.research.mcgill.ca/mcgill-group-suicide-studies-mgss/">McGill Group for Suicide Studies</a>. </p>
<p>Using cutting-edge methods to isolate and analyze human brain cells, Turecki’s team has succeeded in precisely identifying the cell types whose function is affected in men <a href="https://doi.org/10.1038/s41593-020-0621-y">who have suffered from major depression</a>, and then discovering that the cell types involved in this illness differ <a href="https://doi.org/10.1038/s41467-023-38530-5">between men and women</a>. </p>
<p>These experimental approaches generate huge data sets that can be examined in subsequent studies. This is the case, for example, of work carried out in my laboratory, which identified signs of persistent changes in neuroplasticity within the prefrontal cortex of people with a history of <a href="https://doi.org/10.1038/s41380-021-01372-y">child abuse</a>. In fact, the studies mentioned above enabled us to discover at least one of the cell types involved in this phenomenon. </p>
<p>In short, the experimental methods we have today allow us to break the brain down into its elementary components in order to understand its functions and dysfunctions.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/552155/original/file-20231004-27-62uc6y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Cerebral hemispheres preserved in formalin" src="https://images.theconversation.com/files/552155/original/file-20231004-27-62uc6y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/552155/original/file-20231004-27-62uc6y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/552155/original/file-20231004-27-62uc6y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/552155/original/file-20231004-27-62uc6y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/552155/original/file-20231004-27-62uc6y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/552155/original/file-20231004-27-62uc6y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/552155/original/file-20231004-27-62uc6y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Leading researchers from many universities around the world benefit from Douglas-Bell Canada Brain Bank samples to advance their research.</span>
<span class="attribution"><span class="source">(Naguib Mechawar)</span>, <span class="license">Fourni par l'auteur</span></span>
</figcaption>
</figure>
<h2>Identify, prevent, screen and treat</h2>
<p>Thanks to the hard work and dedication of the entire DBCBB team, as well as the unfailing support of all its partners, patrons (often anonymous) and funding bodies — particularly the FRQS research fund and Québec’s suicide research network, the <a href="https://reseausuicide.qc.ca">Réseau québécois sur le suicide, les troubles de l'humeur et les troubles associés</a> — this invaluable resource has not only managed to survive, but to grow and become one of the largest brain banks in the world. </p>
<p>There is every reason to believe that, in the years to come, the DBCBB will play an important role in the increasingly precise identification of the biological causes of brain diseases, and, as a result, will contribute to the identification of new targets for better approaches to prevention, screening and treatment.</p><img src="https://counter.theconversation.com/content/216980/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Naguib Mechawar has received funding from CIHR, NSERC, HBHL (CFREF) and FQRS (NEURON ERA-NET and RQSHA).</span></em></p>Montréal is home to one of the world’s largest brain banks, the Douglas-Bell Canada Brain Bank, where discoveries about different neurological and psychiatric diseases are made.Naguib Mechawar, Neurobiologiste, Institut Douglas; Professeur titulaire, Département de psychiatrie, McGill UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2117262023-12-21T10:27:16Z2023-12-21T10:27:16ZSocial media drains our brains and impacts our decision making – podcast<figure><img src="https://images.theconversation.com/files/543273/original/file-20230817-40322-o38kim.jpg?ixlib=rb-1.1.0&rect=798%2C167%2C7788%2C5214&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Social media can make us buy products we don't want, new research shows. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/young-asian-business-woman-connecting-to-social-royalty-free-image/1470073460?phrase=social+media&adppopup=true">Oscar Wong/Moment via Getty Images</a></span></figcaption></figure><p>Ever found yourself scrolling through social media late at night and accidentally buying something you regretted? In this episode of <a href="https://theconversation.com/uk/topics/the-conversation-weekly-98901">The Conversation Weekly</a> podcast, we talk to an advertising expert about recent research into how social media <a href="https://www.tandfonline.com/doi/full/10.1080/15252019.2022.2144780">can overload our brains</a> and make us buy products we don’t need or want.</p>
<iframe src="https://embed.acast.com/60087127b9687759d637bade/6581c0553f03c00017d0f360" frameborder="0" width="100%" height="190px"></iframe>
<p></p>
<p><iframe id="tc-infographic-561" class="tc-infographic" height="100" src="https://cdn.theconversation.com/infographics/561/4fbbd099d631750693d02bac632430b71b37cd5f/site/index.html" width="100%" style="border: none" frameborder="0"></iframe></p>
<p><a href="https://scholar.google.com/citations?user=cXqXHpsAAAAJ&hl=en">Matthew Pittman</a> is a professor of advertising at the University of Tennessee in the US. In 2022, Pittman and his colleague <a href="https://scholar.google.com/citations?user=GqkucpQAAAAJ&hl=en&oi=ao">Eric Haley</a>, conducted three online studies on Americans aged 18-65 to examine how people under various mental loads respond to advertisements differently.</p>
<p>“Our brain has limited resources and it can also be taxed if we try to do too many things at once and once those resources are depleted, there are usually negative consequences,” says Pittman. </p>
<blockquote>
<p>If you’re on the fence about a purchase and you’re under cognitive load and you see a lot of likes or a lot of comments, or maybe it’s very attractive people in the ad that look happy … click, I’m gonna purchase it.</p>
</blockquote>
<p>Pittman found that those who weren’t under <a href="https://doi.org/10.1007/s11251-009-9110-0">cognitive load</a> made more balanced purchasing decisions. But the group that they told to scroll through their Instagram feed for 30 seconds and then look at an advert was more susceptible to cues such as the comments and likes associated with it. </p>
<p>When asked to describe their rationale for buying a product, Pittman was surprised that those under a high mental load had diminished sentence and language capabilities. He found that Instagram put subjects in a mentally exhausted state because they were consuming different types of text, photos and posts.</p>
<blockquote>
<p>People that were not under cognitive load gave grammatically normal sentences that flowed logically, such as this ice cream looked tasty, or I liked the colors, but when people were under cognitive load, even their sentences were more fractured. Which explains why I can’t explain to my wife why I consistently make stupid purchases.</p>
</blockquote>
<p>Listen to the full episode of <a href="https://podfollow.com/the-conversation-weekly/view">The Conversation Weekly</a> to hear the different ways social media impacts our processing abilities and decision-making. </p>
<p>A <a href="https://cdn.theconversation.com/static_files/files/3015/Social_Media_and_Cognitive_Load_Transcript.docx.pdf?1706201893">transcript of this episode</a> is now available.</p>
<hr>
<p><em>Matthew Pittman does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</em></p>
<p><em>This episode was written and produced by Mend Mariwany with production assistance from Katie Flood and our intern Jusneel Mahal. Eloise Stevens does our sound design, and our theme music is by Neeta Sarl. The executive producer is Gemma Ware.</em> </p>
<p><em>You can find us on Twitter <a href="https://twitter.com/TC_Audio">@TC_Audio</a>, on Instagram at <a href="https://www.instagram.com/theconversationdotcom/">theconversationdotcom</a> or <a href="mailto:podcast@theconversation.com">via email</a>. You can also sign up to The Conversation’s <a href="https://theconversation.com/newsletter">free daily email here</a>.</em> </p>
<p><em>Listen to “The Conversation Weekly” via any of the apps listed above, download it directly via our <a href="https://feeds.acast.com/public/shows/60087127b9687759d637bade">RSS feed</a> or find out <a href="https://theconversation.com/how-to-listen-to-the-conversations-podcasts-154131">how else to listen here</a>.</em></p><img src="https://counter.theconversation.com/content/211726/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew Pittman does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New research shows that scrolling through Instagram can effect our processing and language capabilities. Listen to The Conversation Weekly podcast.Mend Mariwany, Producer, The Conversation Weekly Podcast, The ConversationLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2200442023-12-18T16:17:12Z2023-12-18T16:17:12ZA new supercomputer aims to closely mimic the human brain — it could help unlock the secrets of the mind and advance AI<figure><img src="https://images.theconversation.com/files/566252/original/file-20231218-15-hajmbj.jpg?ixlib=rb-1.1.0&rect=19%2C9%2C6470%2C3940&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/businessman-touching-digital-human-brain-cell-582507070">Sdecoret / Shutterstock</a></span></figcaption></figure><p>A supercomputer scheduled to go online in April 2024 will rival the estimated rate of operations in the human brain, <a href="https://www.westernsydney.edu.au/newscentre/news_centre/more_news_stories/world_first_supercomputer_capable_of_brain-scale_simulation_being_built_at_western_sydney_university">according to researchers in Australia</a>. The machine, called DeepSouth, is capable of performing 228 trillion operations per second. </p>
<p>It’s the world’s first supercomputer capable of simulating networks of neurons and synapses (key biological structures that make up our nervous system) at the scale of the human brain.</p>
<p>DeepSouth belongs to an approach <a href="https://www.nature.com/articles/s43588-021-00184-y">known as neuromorphic computing</a>, which aims to mimic the biological processes of the human brain. It will be run from the International Centre for Neuromorphic Systems at Western Sydney University.</p>
<p>Our brain is the most amazing computing machine we know. By distributing its
computing power to billions of small units (neurons) that interact through trillions of connections (synapses), the brain can rival the most powerful supercomputers in the world, while requiring only the same power used by a fridge lamp bulb.</p>
<p>Supercomputers, meanwhile, generally take up lots of space and need large amounts of electrical power to run. The world’s most powerful supercomputer, the <a href="https://www.hpe.com/uk/en/compute/hpc/cray/oak-ridge-national-laboratory.html">Hewlett Packard Enterprise Frontier</a>, can perform just over one quintillion operations per second. It covers 680 square metres (7,300 sq ft) and requires 22.7 megawatts (MW) to run. </p>
<p>Our brains can perform the same number of operations per second with just 20 watts of power, while weighing just 1.3kg-1.4kg. Among other things, neuromorphic computing aims to unlock the secrets of this amazing efficiency.</p>
<h2>Transistors at the limits</h2>
<p>On June 30 1945, the mathematician and physicist <a href="https://www.ias.edu/von-neumann">John von Neumann</a> described the design of a new machine, the <a href="https://ieeexplore.ieee.org/document/194089">Electronic Discrete Variable Automatic Computer (Edvac)</a>. This effectively defined the modern electronic computer as we know it. </p>
<p>My smartphone, the laptop I am using to write this article and the most powerful supercomputer in the world all share the same fundamental structure introduced by von Neumann almost 80 years ago. <a href="https://www.sciencedirect.com/topics/computer-science/von-neumann-architecture">These all have distinct processing and memory units</a>, where data and instructions are stored in the memory and computed by a processor.</p>
<p>For decades, the number of transistors on a microchip doubled approximately every two years, <a href="https://ieeexplore.ieee.org/abstract/document/591665">an observation known as Moore’s Law</a>. This allowed us to have smaller and cheaper computers. </p>
<p>However, transistor sizes are now approaching the atomic scale. At these tiny sizes, excessive heat generation is a problem, as is a phenomenon called quantum tunnelling, which interferes with the functioning of the transistors. <a href="https://qz.com/852770/theres-a-limit-to-how-small-we-can-make-transistors-but-the-solution-is-photonic-chips#:%7E:text=They're%20made%20of%20silicon,we%20can%20make%20a%20transistor.">This is slowing down</a> and will eventually halt transistor miniaturisation.</p>
<p>To overcome this issue, scientists are exploring new approaches to
computing, starting from the powerful computer we all have hidden in our heads, the human brain. Our brains do not work according to John von Neumann’s model of the computer. They don’t have separate computing and memory areas. </p>
<p>They instead work by connecting billions of nerve cells that communicate information in the form of electrical impulses. Information can be passed from <a href="https://qbi.uq.edu.au/brain-basics/brain/brain-physiology/action-potentials-and-synapses">one neuron to the next through a junction called a synapse</a>. The organisation of neurons and synapses in the brain is flexible, scalable and efficient. </p>
<p>So in the brain – and unlike in a computer – memory and computation are governed by the same neurons and synapses. Since the late 1980s, scientists have been studying this model with the intention of importing it to computing.</p>
<figure class="align-center ">
<img alt="Microchip." src="https://images.theconversation.com/files/566265/original/file-20231218-25-yjbwxy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566265/original/file-20231218-25-yjbwxy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566265/original/file-20231218-25-yjbwxy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566265/original/file-20231218-25-yjbwxy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566265/original/file-20231218-25-yjbwxy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566265/original/file-20231218-25-yjbwxy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566265/original/file-20231218-25-yjbwxy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The continuing miniaturisation of transistors on microchips is limited by the laws of physics.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/close-presentation-new-generation-microchip-gloved-691548583">Gorodenkoff / Shutterstock</a></span>
</figcaption>
</figure>
<h2>Imitation of life</h2>
<p>Neuromorphic computers are based on intricate networks of simple, elementary processors (which act like the brain’s neurons and synapses). The main advantage of this is that these machines <a href="https://www.electronicsworld.co.uk/advances-in-parallel-processing-with-neuromorphic-analogue-chip-implementations/34337/">are inherently “parallel”</a>. </p>
<p>This means that, <a href="https://www.pnas.org/doi/full/10.1073/pnas.95.3.933">as with neurons and synapses</a>, virtually all the processors in a computer can potentially be operating simultaneously, communicating in tandem.</p>
<p>In addition, because the computations performed by individual neurons and synapses are very simple compared with traditional computers, the energy consumption is orders of magnitude smaller. Although neurons are sometimes thought of as processing units, and synapses as memory units, they contribute to both processing and storage. In other words, data is already located where the computation requires it.</p>
<p>This speeds up the brain’s computing in general because there is no separation between memory and processor, which in classical (von Neumann) machines causes a slowdown. But it also avoids the need to perform a specific task of accessing data from a main memory component, as happens in conventional computing systems and consumes a considerable amount of energy. </p>
<p>The principles we have just described are the main inspiration for DeepSouth. This is not the only neuromorphic system currently active. It is worth mentioning the <a href="https://www.humanbrainproject.eu">Human Brain Project (HBP)</a>, funded under an <a href="https://ec.europa.eu/futurium/en/content/fet-flagships.html">EU initiative</a>. The HBP was operational from 2013 to 2023, and led to BrainScaleS, a machine located in Heidelberg, in Germany, that emulates the way that neurons and synapses work. </p>
<p><a href="https://www.humanbrainproject.eu/en/science-development/focus-areas/neuromorphic-computing/hardware/">BrainScaleS</a> can simulate the way that neurons “spike”, the way that an electrical impulse travels along a neuron in our brains. This would make BrainScaleS an ideal candidate to investigate the mechanics of cognitive processes and, in future, mechanisms underlying serious neurological and neurodegenerative diseases.</p>
<p>Because they are engineered to mimic actual brains, neuromorphic computers could be the beginning of a turning point. Offering sustainable and affordable computing power and allowing researchers to evaluate models of neurological systems, they are an ideal platform for a range of applications. They have the potential to both advance our understanding of the brain and offer new approaches to artificial intelligence.</p><img src="https://counter.theconversation.com/content/220044/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Domenico Vicinanza does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Neuromorphic computers aim to one day replicate the amazing efficiency of the brain.Domenico Vicinanza, Associate Professor of Intelligent Systems and Data Science, Anglia Ruskin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2168342023-12-14T23:40:30Z2023-12-14T23:40:30ZChristmas drinks anyone? Why alcohol before bedtime leaves you awake at 3am, desperate for sleep<figure><img src="https://images.theconversation.com/files/564156/original/file-20231207-21-eolo35.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1000%2C666&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/new-year-christmas-celebration-champagne-front-1534963964">fornStudio/Shutterstock</a></span></figcaption></figure><p>You’ve come home after a long day at work, you have dinner, put the kids to bed, and then you have your usual nightcap before drifting off to sleep. Or, perhaps you’re at the pub for the work Christmas party, and you think you’ll just have one more drink before heading home.</p>
<p>That last drink might help you fall asleep easily. But your nightcap can also wreck a good night’s sleep. How could it do both?</p>
<p>Here’s what’s going on in your body when you drink alcohol just before bedtime. And if you want to drink at the Christmas party, we have some tips on how to protect your sleep.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-can-i-get-some-sleep-which-treatments-actually-work-212964">How can I get some sleep? Which treatments actually work?</a>
</strong>
</em>
</p>
<hr>
<h2>What happens to my body when I drink?</h2>
<p>Soon after you drink, alcohol enters your bloodstream and travels to your brain.</p>
<p><a href="https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1530-0277.1998.tb03695.x">There</a>, it affects chemical messengers known as neurotransmitters and <a href="https://pubmed.ncbi.nlm.nih.gov/2700603/">slows down communication</a> between nerve cells. </p>
<p>Certain <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4040959/">regions of the brain</a> are particularly vulnerable to the effects of alcohol. When alcohol interacts with cells in these regions, the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6826822/">overall effect</a> leads to those characteristic feelings of relaxation, lowered inhibitions, slurred speech, and may induce feelings of drowsiness and lethargy. </p>
<p>Alcohol can also have immediate effects on the heart and circulatory system. Blood vessels widen, resulting in a <a href="https://link.springer.com/article/10.1007/s11906-021-01160-7">drop in blood pressure</a>, which can make you feel dizzy or lightheaded.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/do-different-drinks-make-you-different-drunk-88247">Do different drinks make you different drunk?</a>
</strong>
</em>
</p>
<hr>
<h2>What happens soon after a nightcap?</h2>
<p>Drinking alcohol before sleeping is like flipping a switch. At first, alcohol has a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6826822/">sedative effect</a> and you will probably feel <a href="https://pubmed.ncbi.nlm.nih.gov/23347102/">more relaxed</a> and <a href="https://www.nature.com/articles/s41598-020-62227-0#:%7E:text=In%20this%20large%2C%20population%20based,sleep%20(cross%20sectional%20analyses).">drift off easily</a>.</p>
<p>At this point, you still have a high level of alcohol in your blood. But don’t be fooled. As your body <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5821259/">processes the alcohol</a>, and the night goes on, alcohol actually <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/acer.12621">disrupts your sleep</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/564151/original/file-20231207-29-tofekf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Man sitting on sofa, wearing pyjamas, holding glass of red wine, sparkling lights on floor" src="https://images.theconversation.com/files/564151/original/file-20231207-29-tofekf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564151/original/file-20231207-29-tofekf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564151/original/file-20231207-29-tofekf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564151/original/file-20231207-29-tofekf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564151/original/file-20231207-29-tofekf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564151/original/file-20231207-29-tofekf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564151/original/file-20231207-29-tofekf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A nightcap might help you drop off, but there’s worse to come.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/man-check-pyjamas-holding-glass-red-1901882026">dabyki.nadya/Shutterstock</a></span>
</figcaption>
</figure>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-do-i-fall-asleep-on-the-sofa-but-am-wide-awake-when-i-get-to-bed-208371">Why do I fall asleep on the sofa but am wide awake when I get to bed?</a>
</strong>
</em>
</p>
<hr>
<h2>And later that night?</h2>
<p>As your body processes the alcohol and your blood alcohol level drops, your brain rebounds from the drowsiness you would have felt earlier in the night. </p>
<p>This disturbs your sleep, and can wake you up <a href="https://journals.sagepub.com/doi/10.1300/J465v26n01_01">multiple times</a>, particularly in the second half of the night. You may also have
vivid and stressful <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5821259/">dreams</a>.</p>
<p>This sleep disruption is mainly to the deep, “rapid eye movement” or REM sleep.</p>
<p>This type of sleep plays an important role in regulating your emotions and for your cognitive function. So not getting enough explains why you wake up feeling pretty lousy and groggy.</p>
<p>Drinking alcohol before bedtime also tends to mean you <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2775419/?source=post_page---------------------------">sleep less overall</a>, meaning important rest and recharge time is cut short.</p>
<p>There are also <a href="https://pubmed.ncbi.nlm.nih.gov/31234199/">long-term impacts</a> of alcohol on sleep. Moderate and heavy drinkers consistently have <a href="https://academic.oup.com/sleepadvances/article/3/1/zpac023/6632721">poor sleep quality</a> and more <a href="https://www.nature.com/articles/s41598-020-62227-0#:%7E:text=In%20this%20large%2C%20population%20based,sleep%20(cross%20sectional%20analyses).">sleep disturbances</a> over time.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/adele-called-herself-a-borderline-alcoholic-but-is-that-a-real-thing-215987">Adele called herself a 'borderline alcoholic'. But is that a real thing?</a>
</strong>
</em>
</p>
<hr>
<h2>How about the Christmas party then?</h2>
<p>If you plan to drink this holiday season, here are some tips to minimise the effect of alcohol on your sleep:</p>
<ul>
<li><p><strong>swap every other drink</strong>. Try swapping every second drink for a non-alcoholic drink. The more alcohol you drink, <a href="https://academic.oup.com/sleep/article/44/1/zsaa135/5871424?casa_token=okbJAuf8TXUAAAAA:ye_q-DACToxvj8H3IVaiKrjNkDhHZnl-LKJdds3iteaKyzJFuHUzitlRv45DqxNO-FraDRAlQMV53z8">the more</a> sleep disruption you can expect. Reducing how much you drink in any one sitting can minimise the effect on your sleep</p></li>
<li><p><strong>avoid drinking alcohol close to bedtime</strong>. If you give your body a chance to process the alcohol before you go to sleep, your sleep will be less disrupted</p></li>
<li><p><strong>eat while you drink</strong>. Drinking on an empty stomach is going to worsen the effects of alcohol as the alcohol will be absorbed <a href="https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1467-3010.2006.00588.x?casa_token=TQiCqcbasYAAAAAA:GbEvnTT82aB3_sPfmJLOQXIV3ivjnbZdIoP2_XZBa8IDZ0YLaPxNfE6DMHLgH7obnpA22VDsM4vyGZV4dQ">faster</a>. So try to eat something while you’re drinking</p></li>
<li><p><strong>ditch the espresso martinis and other caffeinated drinks</strong>. <a href="https://www.sciencedirect.com/science/article/pii/S1087079207000937?casa_token=NJsobF-C-vwAAAAA:opzPjrglPdZTwXEo7rHil5vm0a1K3KmXw9vp0Het-eRHZEWbfRAA40vgicU3Z5kC8x7uEJF39C8">Caffeine</a> can make it hard to get to sleep, and hard to stay asleep</p></li>
<li><p><strong>be careful if you have sleep apnoea</strong>. People who have sleep apnoea (when their upper airway is repeatedly blocked during sleep) can be even more impacted by drinking alcohol. That’s because alcohol can act as a muscle relaxant, <a href="https://academic.oup.com/sleep/article/5/4/318/2753287">leading to</a> more snoring, and lower oxygen levels in the blood. If you have sleep apnoea, limiting how much alcohol you drink is the best way to avoid these effects</p></li>
<li><p><strong>drink plenty of water</strong>. Staying hydrated will help you <a href="https://academic.oup.com/sleep/article/42/2/zsy210/5155420">sleep better</a> and will hopefully stave off the worst of tomorrow’s hangover.</p></li>
</ul>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-causes-hangovers-blackouts-and-hangxiety-everything-you-need-to-know-about-alcohol-these-holidays-127995">What causes hangovers, blackouts and 'hangxiety'? Everything you need to know about alcohol these holidays</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/216834/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Here’s what’s going on in your body when you drink alcohol just before bedtime. And if you want to drink at the Christmas party, we have some tips on how to protect your sleep.Madeline Sprajcer, Lecturer in Psychology, CQUniversity AustraliaCharlotte Gupta, Postdoctoral research fellow, CQUniversity AustraliaChris Irwin, Senior Lecturer in Nutrition and Dietetics, School of Health Sciences & Social Work, Griffith UniversityGrace Vincent, Senior Lecturer, Appleton Institute, CQUniversity AustraliaSaman Khalesi, Senior Lecturer and Discipline Lead in Nutrition, School of Health, Medical and Applied Sciences, CQUniversity AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2196692023-12-13T19:01:44Z2023-12-13T19:01:44ZHuman intelligence: how cognitive circuitry, rather than brain size, drove its evolution<figure><img src="https://images.theconversation.com/files/565513/original/file-20231213-20-grbqn0.png?ixlib=rb-1.1.0&rect=25%2C33%2C2779%2C1837&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">wikipedia/Foley</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>It’s one of the great paradoxes of evolution. Humans have demonstrated that having <a href="https://theconversation.com/why-do-humans-have-such-large-brains-our-study-suggests-ecology-was-the-driving-force-96873">large brains</a> are key to our evolutionary success, and yet such brains are extremely rare in other animals. Most get by on tiny brains, and don’t seem to miss the extra brain cells (neurons). </p>
<p>Why? The answer that most biologists have settled on is that large brains are costly in terms of the energy they require to run. And, given the way natural selection works, the benefits <a href="https://pubmed.ncbi.nlm.nih.gov/9234964/">simply don’t exceed the costs</a>. </p>
<p>But is it just a matter of size? Does the way our brains are laid out also affect their costs? A new study, <a href="http://www.science.org/doi/10.1126/sciadv.adi7632">published in Science Advances</a>, has produced some intriguing answers. </p>
<p>All our organs have running costs, but <a href="https://www.jstor.org/stable/2744104">some are cheap and others expensive</a>. Bones, for example, are relatively cheap. Although they make up around 15% of your weight, they only use 5% of your metabolism. Brains are at the other end of the spectrum, and at about 2% of typical human body weight, running them uses around 20% of our metabolism. And this without doing any conscious thinking – it even happens when we’re asleep.</p>
<p>For most animals, the benefits of serious thinking are simply not worth it. But for some reason – the greatest puzzle in human evolution, perhaps – humans found ways to overcome the costs of having a larger brain and reap the benefits.</p>
<p>All this is fairly well known, but there is a more tantalising question. Certainly humans have to bear the greater costs of our brains because they are so large, but are there different costs because of the special nature of our cognition? Does thinking, speaking, being self-conscious or doing sums cost more than typical day-to-day animal activities?</p>
<p>It’s not an easy question to answer, but the team behind the new study, led by Valentin Riedl of the Technical University of Munich, Germany, have risen to the challenge. </p>
<p>The authors had a number of known points to start with. The basic design and structure of neurons is much the same across the brain – and across species. The neuronal density is also the same for humans and other primates, so these are unlikely to be the driver of intelligence. If they were, some animals with large brains such as orcas and elephants would likely be smarter than humans.</p>
<figure class="align-center ">
<img alt="Elephant and woman in village Surin Thailand." src="https://images.theconversation.com/files/565485/original/file-20231213-19-jr94u6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/565485/original/file-20231213-19-jr94u6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/565485/original/file-20231213-19-jr94u6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/565485/original/file-20231213-19-jr94u6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/565485/original/file-20231213-19-jr94u6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/565485/original/file-20231213-19-jr94u6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/565485/original/file-20231213-19-jr94u6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Elephants have larger brains than humans.</span>
<span class="attribution"><span class="source">venusvi/Shutterstock</span></span>
</figcaption>
</figure>
<p>They also knew that across human evolution, the neocortex – the largest part of the outermost layer of the brain, known as cerebral cortex – has expanded at a greater rate than other parts. This region, which involves the prefrontal cortex, is responsible for tasks involving attention, thought, planning, perception and episodic memory – all needed for higher cognitive function.</p>
<p>These two observations led them to investigate whether there are different costs of signalling across different regions of the brain.</p>
<p>The team scanned the brains of 30 people using a technique that could simultaneously measure glucose metabolism (a measure of energy consumption) and the level of signalling across the cortex. They could then look at the correlation between these two elements and see whether different parts of the brain used different levels of energy – and if so how. </p>
<h2>Surprising findings</h2>
<p>Neurobiologists will surely ponder and explore the fine details of the results, but from an evolutionary point of view, they are thought-provoking. What they found is that the difference in energy consumption between different areas of the brain is big. Not all bits of the brain are equal, energetically speaking.</p>
<p>Not only that, but the parts of the human brain that have expanded most had higher costs than expected. The neocortex in fact demanded around 67% more energy than sensorimotor networks per gram of tissue. </p>
<p>This means that during the course of human evolution, not only did the metabolic costs of our brains go up as they became larger, but they did so at an accelerating rate as the neocortex expanded faster than the rest of the brain. </p>
<p>Why should that be the case? A neuron is a neuron, after all. The neocortex relates directly to higher cognitive function. </p>
<p>The signals sent across this area are mediated through brain chemicals such as serotonin, dopamine and noradrenaline (neuromodulators), which create circuits in the brain to help maintain a general level of excitement (in a neurological sense of the word meaning being awake, not having fun). These circuits, which regulate some brain areas more than others, control and modify the ability of neurons across the brain to communicate with each other.</p>
<p>In other words, they keep the brain active for memory storage and thinking – a generally higher level of cognitive activity. Not surprisingly, perhaps, the higher level of activity involved in our advanced cognition comes at a higher energetic cost.</p>
<p>Ultimately then, it seems the human brain evolved to such advanced levels of cognition not just because we have large brains, nor even just because certain areas of our brain grew disproportionately big, but because – at a cost – the connectivity improved.</p>
<p>Many animals with large brains, such as elephants and orcas, are highly intelligent. But it seems it is possible to have a large brain without developing the “right” circuitry for human-level cognition.</p>
<p>The results help us understand why larger brains are so rare. A larger brain can enable more complex cognition to evolve. It is not just a matter of scaling up brains and energy at the same rate though, but taking on additional costs.</p>
<p>This doesn’t really answer the ultimate question – how did humans manage to break through the brain-energy ceiling? As so often in evolution, the answer must lie in ecology, the ultimate source of energy. To grow and maintain a large brain – whatever social, cultural, technological or other things it is used for – <a href="https://royalsocietypublishing.org/doi/10.1098/rstb.1991.0111">requires a dependable and high quality diet</a>.</p>
<p>To learn more, we need to explore the last million years, the period when our ancestors’ brains really expanded, to investigate this interface between energy expenditure and cognition.</p><img src="https://counter.theconversation.com/content/219669/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The human brain uses up 20% of the energy we consume.Robert Foley, Emeritus Professor of Human Evolution, University of CambridgeMarta Mirazon Lahr, Professor of Human Evolutionary Biology & Director of the Duckworth Collection, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2182512023-12-08T13:35:19Z2023-12-08T13:35:19ZThe holidays and your brain – a neuroscientist explains how to identify and manage your emotions<figure><img src="https://images.theconversation.com/files/564372/original/file-20231207-19-phpcrd.jpg?ixlib=rb-1.1.0&rect=129%2C25%2C8517%2C5730&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">When stress and tension are starting to mount, taking short breaks and deep breaths can help clear your mind.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/young-hispanic-woman-standing-by-christmas-tree-royalty-free-image/1333972363?phrase=holiday+stress&searchscope=image%2Cfilm&adppopup=true">AaronAmat/iStock / Getty Images Plus</a></span></figcaption></figure><p>Just as the shift to shorter days and colder weather can bring with it <a href="https://theconversation.com/shorter-days-affect-the-mood-of-millions-of-americans-a-nutritional-neuroscientist-offers-tips-on-how-to-avoid-the-winter-blues-194417">mood swings</a> and other <a href="https://mcpress.mayoclinic.org/mental-health/seasonal-affective-disorder/">emotional challenges</a>, the holiday season can also bring about somewhat predictable changes in mood and behavior. </p>
<p>Around this time of year, many of us experience more stress, anxiety and frustration than usual. These stressors have been linked to <a href="https://doi.org/10.1007/s00392-016-0995-8">higher levels of heart failure</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257984/">alcohol poisoning</a> and an increase in <a href="https://doi.org/10.1161/jaha.118.011888">deaths from stroke</a>.</p>
<p>Learning how to recognize what brings about stress and what parts of the brain are actively involved can help with managing the stress response.</p>
<p>As a neuroscientist, I am often curious about the <a href="https://www.umhb.edu/resources/hr/directory/seena-mathew">dynamic connection between behavior and the brain</a>. I’ve learned that, biologically speaking, there are ways to manage your responses to holiday stressors through awareness of why they happen.</p>
<h2>Harnessing the hypothalamus</h2>
<p>Delays in itineraries, crowded airports and congested highways can easily lead to <a href="https://doi.org/10.1192%2Fbjb.2020.32">frustrations for those traveling</a> to spend time with family or friends. </p>
<p>One region of the brain involved in your response to these types of stresses is the <a href="https://doi.org/10.4103%2F2152-7806.110667">hypothalamus</a>, a structure deep in the brain that is involved in trying to keep the body in a stable state, known as homeostasis. The <a href="https://doi.org/10.1016/b978-0-444-64123-6.00004-7">hypothalamus works to regulate</a> the <a href="https://www.ncbi.nlm.nih.gov/books/NBK539845/">autonomic nervous system</a>, a system that coordinates involuntary responses such as heart rate, blood pressure and respiration. It is the key component of the <a href="https://www.stress.org/how-the-fight-or-flight-response-works">fight-or-flight</a> response to real or perceived threats.</p>
<p>When you are under stress, such as when you learn that your flight has been delayed or even canceled, your hypothalamus stimulates the release of stress hormones such as cortisol and epinephrine. These hormones in turn trigger physiological responses like increased heart rate, perspiration and feelings of irritation and frustration. </p>
<p>When you experience these stressors, <a href="https://doi.org/10.3389/fresc.2022.864079">deep breathing exercises</a> can help stimulate the body’s parasympathetic nervous system. This is known as the “rest and digest” system because it is responsible for helping your body relax and recover from stress. By taking slow, deep breaths, you can engage the parasympathetic nervous system, which can in turn <a href="https://doi.org/10.1155/2021/5924040">calm your nerves</a> and reduce frustrations.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Nfe7n2OC3Zc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">It’s important to take time to recharge during the holidays, whether it be through yoga, meditation, a trip to the gym or even cuddling with a pet.</span></figcaption>
</figure>
<h2>Family dynamics and interactions</h2>
<p>Getting together with family during the holidays can bring about complicated emotions when there are conflicting personalities, unresolved issues or <a href="http://dx.doi.org/10.21832/9781845413286-012">awkward family dynamics</a>.</p>
<p>Frustrating or aggravating conversations with relatives often trigger a region of the brain known as the <a href="https://neuroscientificallychallenged.com/glossary/anterior-cingulate-cortex#">anterior cingulate cortex</a>. The anterior cingulate cortex has a unique position in the brain, establishing connections with both the <a href="https://doi.org/10.4103/0019-5545.33264">“emotional” limbic</a> system and the “<a href="https://doi.org/10.1176/jnp.23.2.jnp121">cognitive” prefrontal cortex</a>. </p>
<p>This brain region is involved in monitoring and regulating cognitive processes, <a href="https://doi.org/10.1162/jocn_a_01023">conflict resolution</a> and error detection. It plays a role in processing frustration by signaling when there is a conflict between expectations and outcomes. The anterior cingulate cortex is also involved in what’s known as <a href="https://doi.org/10.1007%2Fs00429-019-01945-2">action-outcome learning</a>, where you evaluate the consequence of an action and adjust your behavior based on feedback.</p>
<p>When you are feeling overwhelmed or frustrated, <a href="https://doi.org/10.1016/j.annale.2020.100006">taking short breaks</a> to step away from the situation can provide a fresh perspective and allow you to return with a clearer mindset. This break will allow you to reinforce this action-outcome learning, helping you learn to associate an action – a short break – with the outcome of the action, which is more relaxed breathing and a clearer mind. </p>
<h2>Financial worries</h2>
<p>The holiday season can put an unnecessary burden on those who are <a href="https://doi.org/10.1371%2Fjournal.pone.0264041">experiencing economic or financial hardship</a>. The cost of hosting a holiday meal, buying gifts or traveling can contribute additional financial strain during an already stressful time. </p>
<p>The brain region <a href="https://doi.org/10.1016%2Fj.pneurobio.2015.12.006">primarily associated with memory and learning</a> is the <a href="https://doi.org/10.4103%2F0972-2327.104323">hippocampus</a>. When you recall past experiences, such as how much you spent last year during the holidays or remember that the credit card bill is coming soon, you activate your hippocampus. The hippocampus is critical in the interplay of memory formation and recall and retrieval of individual episodic memories. </p>
<p>Some ways to reduce stress may be to make gifts for friends and family instead of purchasing them. To help cut down on travel costs, perhaps take a virtual holiday visit now, followed by an in-person visit later when it is less expensive or when financial strains have eased. When reminded of <a href="https://doi.org/10.3758/s13415-021-00973-y">stressful experiences</a>, the hippocampus sends signals to the hypothalamus and other brain regions to help restore balance in your mind. The hippocampus also aids in your adaptation to these stressors by helping you learn how to <a href="https://doi.org/10.1016/j.cortex.2019.01.005">adjust your expectations</a>. In the end, you have to remind yourself that it truly is the thought that counts most.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/564352/original/file-20231207-29-bg6nm0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Illustration of a human brain highlighting various brain regions that are associated with stress." src="https://images.theconversation.com/files/564352/original/file-20231207-29-bg6nm0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/564352/original/file-20231207-29-bg6nm0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=483&fit=crop&dpr=1 600w, https://images.theconversation.com/files/564352/original/file-20231207-29-bg6nm0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=483&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/564352/original/file-20231207-29-bg6nm0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=483&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/564352/original/file-20231207-29-bg6nm0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=607&fit=crop&dpr=1 754w, https://images.theconversation.com/files/564352/original/file-20231207-29-bg6nm0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=607&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/564352/original/file-20231207-29-bg6nm0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=607&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Some key brain regions involved in restoring balance in the mind.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/posttraumatic-stress-disorder-royalty-free-illustration/1176650050?phrase=brain+regions">ttsz/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<h2>Loneliness and isolation</h2>
<p>Feelings of <a href="https://doi.org/10.1111/psyp.13031">isolation and loneliness</a> can arise for those of us who may not have family or friends to celebrate with, or perhaps are unable to travel to see those we love. </p>
<p>This is where the “<a href="https://doi.org/10.1038/s41467-021-23623-w">default network</a>” of the brain plays a role. This network, made up of brain regions including the amygdala, is involved in thoughts of future planning, reminiscing and imagining. The <a href="https://www.ncbi.nlm.nih.gov/books/NBK537102/">amygdala</a> is a part of the limbic system and is associated with processing of negative emotions to stimuli, such as the irritation from not being able to travel, and how you react.</p>
<p>Studies have shown that you can help improve your mood and reduce feelings of frustration and irritation by having a <a href="https://doi.org/10.3390/ijerph19106078">regular exercise routine</a>. Physical activity can be an effective outlet for releasing built-up tension and stress. Aerobic exercise can also modulate <a href="https://doi.org/10.3390%2Flife11060577">connections between and within the amygdala</a> and help reduce feelings of depression. As an added bonus, if you work out in a gym or park, you have an opportunity to be around others, which can help you feel more connected with communities of people with similar interests.</p>
<h2>Political discussions</h2>
<p>Family gatherings can lead to <a href="https://doi.org/10.1371/journal.pone.0262022">discussions about current events or politics</a>, which can result in heated debates and disagreements among family members. These conversations can be very frustrating and even upsetting, especially in <a href="https://doi.org/10.3389/fpos.2020.587588">today’s polarized world</a>. </p>
<p>The <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/prefrontal-cortex">prefrontal cortex</a> is an area of the brain involved in <a href="https://doi.org/10.1016%2Fj.biopsych.2010.07.005">impulse control</a>, decision-making and emotional regulation. It plays a crucial role in assessing certain situations, such as supercharged conversations, and it helps you evaluate and consider your potential actions and temper your emotional responses. Understanding what triggers your frustration in these situations is crucial to developing proactive strategies to manage or avoid them. </p>
<p>For instance, this might take the form of <a href="https://doi.org/10.1177%2F2374373517699267">empathizing with the opposing side</a> or perhaps stepping away from the table when voices start to rise or you feel your emotions building. The <a href="https://doi.org/10.1111%2Fj.1467-8624.2009.01326.x">prefrontal cortex plays a dual role</a> in regulating the relationship of your initial emotional reaction and the shift to your empathetic emotion. Your ability to build empathetic perspectives and increase cognitive control helps to further develop your prefrontal cortex, potentially making it easier to de-escalate the next time around.</p>
<h2>One step at a time</h2>
<p>Reducing frustration is a gradual process, and different strategies work for different people. </p>
<p>It is important to identify the root cause of your stress and frustration so that you can develop your own targeted coping strategies. Some examples include engaging in a hobby, listening to music, going on a walk or run, or simply practicing relaxation techniques. It is essential to experiment with various techniques and not be afraid to move away from ones that don’t work and toward ones that do. </p>
<p>The most important thing to remember is that retraining your brain is more of a marathon and not a sprint. It will include trial and error and open-mindedness, but if you focus on identifying your triggers and adapting your own coping strategies, it will almost certainly get better with time.</p><img src="https://counter.theconversation.com/content/218251/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Seena Mathew does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>It’s important to identify the root causes of your stress and to find the coping mechanisms that work best for you.Seena Mathew, Assistant Professor of Biology, University of Mary Hardin-BaylorLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2178892023-12-06T13:27:31Z2023-12-06T13:27:31ZHow electroconvulsive therapy heals the brain − new insights into ECT, a stigmatized yet highly effective treatment for depression<figure><img src="https://images.theconversation.com/files/563043/original/file-20231201-17-j1qrjt.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2059%2C1454&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Electroconvulsive therapy involves inducing a controlled seizure under anesthesia.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/human-brain-impulse-concept-futuristic-royalty-free-illustration/1177917141">Inkoly/iStock via Getty Images Plus</a></span></figcaption></figure><p>When most people hear about <a href="https://theconversation.com/electroconvulsive-therapy-a-history-of-controversy-but-also-of-help-70938">electroconvulsive therapy, or ECT</a>, it typically conjures terrifying images of cruel, outdated and pseudo-medical procedures. Formerly known as electroshock therapy, this perception of ECT as dangerous and ineffective has been reinforced in pop culture for decades – think the 1962 novel-turned-Oscar-winning film “<a href="https://www.britannica.com/topic/One-Flew-over-the-Cuckoos-Nest-film-by-Forman">One Flew Over the Cuckoo’s Nest</a>,” where an unruly patient is subjected to ECT as punishment by a tyrannical nurse.</p>
<p>Despite this stigma, ECT is a <a href="https://doi.org/10.1056/nejmra2034954">highly effective treatment for depression</a> – up to 80% of patients experience at least a 50% reduction in symptom severity. For one of the <a href="https://doi.org/10.1016/S0140-6736(20)30925-9">most disabling illnesses</a> around the world, I think it’s surprising that ECT is <a href="https://doi.org/10.1097/yct.0000000000000320">rarely used</a> to treat depression.</p>
<p>Contributing to the stigma around ECT, psychiatrists still don’t know exactly how it heals a depressed person’s brain. ECT involves using <a href="https://www.ncbi.nlm.nih.gov/books/NBK538266/">highly controlled doses of electricity</a> to induce a brief seizure under anesthesia. Often, the best description you’ll hear from a physician on why that brief seizure can alleviate depression symptoms is that ECT <a href="https://www.uhhospitals.org/services/adult-psychiatry-psychology/ect-suite/about-ect-procedure">“resets” the brain</a> – an answer that can be fuzzy and unsettling to some.</p>
<p>As a <a href="https://scholar.google.com/citations?hl=en&user=tDUCQ3UAAAAJ">data-obsessed neuroscientist</a>, I was also dissatisfied with this explanation. In <a href="https://doi.org/10.1038/s41398-023-02631-y">our newly</a> <a href="https://doi.org/10.1038/s41398-023-02634-9">published research</a>, my colleagues and I in <a href="https://voyteklab.com">the lab of</a> <a href="https://scholar.google.com/citations?user=ydFvGx0AAAAJ&hl=en">Bradley Voytek</a> at UC San Diego discovered that ECT might work by resetting the brain’s electrical background noise.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/AcmarVpo2xE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Despite its high effectiveness in alleviating depression symptoms, misperceptions about ECT made it unpopular.</span></figcaption>
</figure>
<h2>Listening to brain waves</h2>
<p>To study how ECT treats depression, my team and I used a device called an <a href="https://www.ncbi.nlm.nih.gov/books/NBK563295/">electroencephalogram, or EEG</a>. It measures the brain’s electrical activity – or brain waves – via electrodes placed on the scalp. You can think of brain waves as music played by an orchestra. Orchestral music is the sum of many instruments together, much like EEG readings are the sum of the electrical activity of millions of brain cells.</p>
<p>Two <a href="https://doi.org/10.1038/s41593-020-00744-x">types of electrical activity</a> make up brain waves. The first, oscillations, are like the highly synchronized, melodic music you might hear in a symphony. The second, aperiodic activity, is more like the asynchronous noise you hear as musicians tune their instruments. These two types of activities coexist in the brain, together creating the electrical waves an EEG records.</p>
<p>Importantly, tuning noises and symphonic music shouldn’t be mistaken for one another. They clearly come from different processes and serve different purposes. The brain is similar in this way – aperiodic activity and oscillations are different because the biology driving them is distinct.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/563769/original/file-20231205-27-cj7f46.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram showing EEG reading of neural oscillations and aperiodic activity" src="https://images.theconversation.com/files/563769/original/file-20231205-27-cj7f46.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/563769/original/file-20231205-27-cj7f46.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=134&fit=crop&dpr=1 600w, https://images.theconversation.com/files/563769/original/file-20231205-27-cj7f46.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=134&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/563769/original/file-20231205-27-cj7f46.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=134&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/563769/original/file-20231205-27-cj7f46.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=169&fit=crop&dpr=1 754w, https://images.theconversation.com/files/563769/original/file-20231205-27-cj7f46.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=169&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/563769/original/file-20231205-27-cj7f46.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=169&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This diagram shows two EEG readings: One signal contains slow neural oscillations and the other contains only aperiodic activity. Although these signals can be tricky to visually distinguish, certain data analysis methods can help tease them apart.</span>
<span class="attribution"><span class="source">Sydney Smith</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>However, the methods neuroscientists have traditionally used to analyze these signals are <a href="https://doi.org/10.1038/s41593-020-00744-x">unable to differentiate</a> between the oscillations (symphony) and the aperiodic activity (tuning). Both are critical for the orchestra, but so far neuroscientists have mostly ignored – or entirely missed – aperiodic signals because they were thought to be just the brain’s background noise.</p>
<p>In our new research, my team and I show that ignoring aperiodic brain activity <a href="https://doi.org/10.1038/s41398-023-02631-y">likely explains</a> <a href="https://doi.org/10.1038/s41398-023-02634-9">the confusion</a> behind about how ECT treats depression. It turns out we’ve been missing this signal all along.</p>
<h2>Connecting aperiodic activity and ECT</h2>
<p>Since the 1940s, ECT has been associated with <a href="https://doi.org/10.1176/ajp.99.4.525">increases in slow oscillations</a> in the brain waves of patients. However, those slow oscillations have never been linked to how ECT works. The degree to which slow oscillations appear is not consistently related to how much symptoms improve following ECT. Nor have ideas about how the brain produces slow oscillations connected those processes to the pathology underlying depression. </p>
<p>Because these two types of brain waves are <a href="https://doi.org/10.1007/s12021-022-09581-8">difficult to separate in measurements</a>, I wondered if these slow oscillations were in fact incorrectly measured aperiodic activity. Returning to our orchestra analogy, I believed that scientists had misidentified the tuning sounds as symphony music.</p>
<p>To investigate this, my team and I gathered three EEG datasets: one from nine patients with depression undergoing ECT in San Diego, another from 22 patients in Toronto receiving ECT and a third from 22 patients in Toronto participating in a clinical trial of <a href="https://doi.org/10.1001/archpsyc.58.3.303">magnetic seizure therapy, or MST</a>, a newer alternative to ECT that starts a seizure with magnets instead of electricity.</p>
<p>We found that aperiodic activity increases by <a href="https://doi.org/10.1038/s41398-023-02634-9">more than 40% on average</a> following ECT. In patients who received MST treatment, aperiodic activity increases more modestly, <a href="https://doi.org/10.1038/s41398-023-02631-y">by about 16%</a>. After accounting for changes in aperiodic activity, we found that slow oscillations do not change much at all. In fact, slow oscillations were not even detected in some patients, and aperiodic activity dominated their EEG recordings instead.</p>
<h2>How ECT treats depression</h2>
<p>But what does aperiodic activity have to do with depression?</p>
<p>A long-standing <a href="https://doi.org/10.1038/mp.2010.120">theory of depression</a> states that severely depressed patients have too few of a type of brain cell called inhibitory cells. These cells can turn other brain cells on and off, and maintaining the balance of these on and off states is critical for healthy brain function. This balance is particularly relevant for depression because the brain’s ability to turn cells off plays an important role in <a href="https://doi.org/10.2174%2F1570159X1304150831150507">how it responds to stress</a>, a function that, when not working properly, makes people particularly vulnerable to depression.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/563047/original/file-20231201-21-7jfwil.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Microscopy image of a long green neuron touching a red neuron" src="https://images.theconversation.com/files/563047/original/file-20231201-21-7jfwil.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/563047/original/file-20231201-21-7jfwil.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=596&fit=crop&dpr=1 600w, https://images.theconversation.com/files/563047/original/file-20231201-21-7jfwil.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=596&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/563047/original/file-20231201-21-7jfwil.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=596&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/563047/original/file-20231201-21-7jfwil.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=749&fit=crop&dpr=1 754w, https://images.theconversation.com/files/563047/original/file-20231201-21-7jfwil.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=749&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/563047/original/file-20231201-21-7jfwil.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=749&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This microscopy image shows a mouse inhibitory neuron (red) contacting a pyramidal neuron (green).</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/J8HizN">McBain Laboratory, NICHD/NIH via Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Using a <a href="https://doi.org/10.1016/j.neuroimage.2017.06.078">mathematical model</a> of cell type-based electrical activity, I linked increases in aperiodic activity, like those seen in the ECT patients, to a huge <a href="https://doi.org/10.1038/s41398-023-02634-9">change in the activity</a> of these inhibitory cells. This change in aperiodic activity may be restoring the crucial on and off balance in the brain to a healthy level. </p>
<p>Even though scientists have been recording EEGs from ECT patients for decades, this is the first time that brain waves have been connected to this particular brain malfunction.</p>
<p>Altogether, though our sample size is relatively small, our findings indicate that ECT and MST likely treat depression by resetting aperiodic activity and restoring the function of inhibitory brain cells. Further study can help destigmatize ECT and highlight new directions for the research and development of depression treatments. Listening to the nonmusical background noise of the brain could help solve other mysteries, like how the brain changes in aging and in illnesses like schizophrenia and epilepsy.</p><img src="https://counter.theconversation.com/content/217889/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sydney E. Smith does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Electroconvulsive therapy often evokes inaccurate images of seizing bodies and smoking ears. Better understanding of how it reduces depression symptoms can illuminate new ways to treat mental illness.Sydney E. Smith, Ph.D. Candidate in Computational Neuroscience, University of California, San DiegoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2180032023-11-28T17:55:45Z2023-11-28T17:55:45ZLifestyle changes can reduce dementia risk by maintaining brain plasticity — but the time to act is now<figure><img src="https://images.theconversation.com/files/561624/original/file-20231125-24-4dpbbp.jpg?ixlib=rb-1.1.0&rect=0%2C704%2C5714%2C3742&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lifestyle changes may be our best hope of delaying dementia or not developing dementia at all.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/lifestyle-changes-can-reduce-dementia-risk-by-maintaining-brain-plasticity-but-the-time-to-act-is-now" width="100%" height="400"></iframe>
<p>Walk 10,000 steps a day, cut back alcohol, get better sleep at night, stay socially active — we’re told that changes like these can <a href="https://doi.org/10.1016/S0140-6736(20)30367-6">prevent up to 40 per cent of dementia cases worldwide</a>. </p>
<p>Given that dementia is still one of <a href="https://doi.org/10.1186%2Fs12889-023-15772-y">the most feared diseases</a>, why aren’t we pushing our doctors and governments to support these lifestyle changes through new programs and policy initiatives?</p>
<p>The truth, however, is more complex. We know that <a href="https://theconversation.com/got-health-goals-research-based-tips-for-adopting-and-sticking-to-new-healthy-lifestyle-behaviours-173740">making lifestyle changes is hard</a>. Ask anyone who has tried to keep their New Year’s resolution to visit the gym three times a week. It can be doubly difficult when the changes we need to make now won’t show results for years, or even decades, and we don’t really understand why they work.</p>
<h2>Taking control of your health</h2>
<p>Anyone who has watched a loved one <a href="https://alzheimer.ca/en/about-dementia/what-dementia/common-questions-about-dementia">living with dementia</a>, facing the small and large indignities and declines that leave them eventually unable to eat, communicate or remember, knows it is a devastating disease. </p>
<p>There are <a href="https://alzheimer.ca/en/whats-happening/events/new-dementia-drugs-therapies-what-canadians-should-know">several new drugs</a> making their way to the market for Alzheimer’s disease (one of the most common forms of dementia). However, they are still far from a cure and are currently only effective for early-stage Alzheimer’s patients.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/lecanemab-experimental-drug-is-a-ray-of-hope-for-alzheimers-disease-196719">Lecanemab: Experimental drug is a ray of hope for Alzheimer's disease</a>
</strong>
</em>
</p>
<hr>
<p>So lifestyle changes may be our best hope of delaying dementia or not developing dementia at all. Actor <a href="https://www.vanityfair.com/hollywood/2022/11/chris-hemsworth-exclusive-interview-alzheimers-limitless">Chris Hemsworth</a> knows it. He watched his grandfather live with Alzheimer’s and is making lifestyle changes after learning he has two copies of the APOE4 gene. This <a href="https://www.reuters.com/business/healthcare-pharmaceuticals/what-is-apoe4-how-does-it-relate-alzheimers-disease-2023-04-21/">gene</a> is a risk factor for Alzheimer’s, and having two copies significantly increases his risk of developing the same condition. </p>
<p>Research has identified <a href="https://doi.org/10.1016/S0140-6736(20)30367-6">modifiable risk factors</a> that contribute to increasing the risk of dementia:</p>
<ul>
<li>physical inactivity</li>
<li>excessive use of alcohol</li>
<li>less sleep</li>
<li>social isolation</li>
<li>hearing loss</li>
<li>less cognitive engagement</li>
<li>poor diet</li>
<li>hypertension</li>
<li>obesity</li>
<li>diabetes</li>
<li>traumatic brain injury</li>
<li>smoking</li>
<li>depression</li>
<li>air pollution</li>
</ul>
<p>Our understanding of the biological mechanisms for these risk factors is varied, with some more clearly understood than others. </p>
<p>But there is a lot we do know — and here’s what you need to know as well.</p>
<h2>Cognitive reserve and neuroplasticity</h2>
<figure class="align-center ">
<img alt="Two older men on a park bench, on of whom is straining to hear the other speaking" src="https://images.theconversation.com/files/561625/original/file-20231125-21-n964o8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/561625/original/file-20231125-21-n964o8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/561625/original/file-20231125-21-n964o8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/561625/original/file-20231125-21-n964o8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/561625/original/file-20231125-21-n964o8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/561625/original/file-20231125-21-n964o8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/561625/original/file-20231125-21-n964o8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">As a person‘s hearing decreases, it can make it difficult to socially engage with others, resulting in a loss of sensory input. The brain has to work harder to compensate for this.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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</figure>
<p><a href="https://doi.org/10.1016/j.neurobiolaging.2019.03.022">Cognitive reserve</a> is the brain’s ability to withstand damage or neurodegenerative disease. If there is tissue or functional loss in one part of the brain, other brain cells (neurons) work harder to compensate. In theory, this means lifelong experiences and activities create a dam against the damages of disease and aging in the brain.</p>
<p><a href="https://doi.org/10.3928/02793695-20100302-01">Neuroplasticity</a> is the brain’s amazing ability to adapt, learn and reorganize, create new pathways or rewire existing ones to recover from damage. The key takeaway is that neuroplasticity can happen at any time and any age, which means learning and activities should be lifelong.</p>
<p>Many of the risk factors linked to dementia likely work in combination, which is why an overall lifestyle approach is crucial. For example, <a href="https://doi.org/10.1007/s11920-016-0721-2">studies have shown</a> that exercise, cognitive and social engagement stimulate your brain and maintain its plasticity by growing new neural connections and building cognitive reserve.</p>
<p>The mechanism behind this is a combination of factors: increased oxygen and blood flow to the brain, stimulating growth factors that keep neurons healthy and reduced inflammation.</p>
<p>The opposite is also true. Poor sleep, diet, social isolation and untreated depression are linked to <a href="https://doi.org/10.3928/02793695-20100302-01">decreased cognitive reserve</a>. </p>
<p>The same rationale applies to hearing loss, a key emerging risk factor for dementia. As a person‘s hearing decreases, it can make it difficult to socially engage with others, resulting in a loss of sensory input. The <a href="https://doi.org/10.1097%2FWAD.0000000000000325">brain has to work harder</a> to compensate for this, potentially drawing down its cognitive reserve and leaving it less able to withstand dementia.</p>
<h2>The role of stress and inflammation</h2>
<figure class="align-center ">
<img alt="Illustration of hand drawing a brain with multicoloured chalk on blackboard" src="https://images.theconversation.com/files/561626/original/file-20231125-17-6hps66.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/561626/original/file-20231125-17-6hps66.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=222&fit=crop&dpr=1 600w, https://images.theconversation.com/files/561626/original/file-20231125-17-6hps66.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=222&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/561626/original/file-20231125-17-6hps66.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=222&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/561626/original/file-20231125-17-6hps66.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=279&fit=crop&dpr=1 754w, https://images.theconversation.com/files/561626/original/file-20231125-17-6hps66.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=279&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/561626/original/file-20231125-17-6hps66.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=279&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Chronic or prolonged inflammation disrupts normal function and causes damage to the brain’s cells.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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</figure>
<p>Stress responses and inflammation are the body’s complex answer to injury. Inflammation is an important component of the body’s immune system, helping defend against threats and repair tissue damage. While short-term inflammation is a natural and good response, chronic or prolonged inflammation disrupts normal function and causes damage to the brain’s cells.</p>
<p>For example, one of the commonalities between dementia and untreated depression is the <a href="https://doi.org/10.17219/acem/149897%22%22">inflammatory process</a>. Prolonged exposure to stress hormones can lead to chronic inflammation. Hypertension, physical inactivity, smoking and air pollution are also associated with chronic inflammation and stress, which can damage blood vessels and neurons in the brain.</p>
<p>In a newer area of research still being explored, <a href="https://globalnews.ca/news/10095898/loneliness-global-public-health-concern-who/">social isolation</a> has also been <a href="https://doi.org/10.1016/j.yfrne.2023.101061">linked to inflammation</a>. As we learned during the COVID-19 pandemic, the brain is wired to respond to social engagement as a means of bonding and emotional support, especially in times of distress. </p>
<p>With surveys showing more than <a href="https://www.thestar.com/opinion/contributors/we-have-a-loneliness-crisis-it-s-time-to-act/article_30e6c996-a9e2-588b-a776-58addc503762.html">one in three Canadians</a> feel isolated, the lack of social connection and loneliness can trigger the body’s stress response and neuroendocrine changes, and prolonged exposure to this inflammatory process can damage the brain.</p>
<h2>Similar pathways across multiple diseases</h2>
<figure class="align-center ">
<img alt="Three women walking in exercise clothes" src="https://images.theconversation.com/files/561627/original/file-20231125-27-f0h7c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/561627/original/file-20231125-27-f0h7c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/561627/original/file-20231125-27-f0h7c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/561627/original/file-20231125-27-f0h7c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/561627/original/file-20231125-27-f0h7c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/561627/original/file-20231125-27-f0h7c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/561627/original/file-20231125-27-f0h7c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">While there are benefits to being physically and socially active at any age, some research shows the payoff from those gains can be higher after age 40 when the body’s metabolism slows, risk factors increase and cognitive reserve becomes even more essential to help protect against cognitive decline.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Several of these risk factors, and their biological pathways, cut across multiple chronic diseases. Accumulating evidence of <a href="https://doi.org/10.1016/S1474-4422(19)30087-0">decades of research</a> supports the concept of “what’s good for your heart is good for your head.” </p>
<p>This means that making these lifestyle changes not only reduces your risk of dementia, but also your risk of diabetes, hypertension and heart concerns. This highlights the complex nature of dementia but also offers a united strategy to deal with multiple health concerns that may arise as people age.</p>
<h2>It’s never too late</h2>
<figure class="align-center ">
<img alt="A man asleep in bed" src="https://images.theconversation.com/files/561628/original/file-20231125-27-dyme8y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/561628/original/file-20231125-27-dyme8y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/561628/original/file-20231125-27-dyme8y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/561628/original/file-20231125-27-dyme8y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/561628/original/file-20231125-27-dyme8y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/561628/original/file-20231125-27-dyme8y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/561628/original/file-20231125-27-dyme8y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Factors like not sleeping enough, having a poor diet and lacking social and cognitive engagement can increase the risk of developing dementia.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>It’s never really too late to change. The human brain and body have a remarkable capacity for adaptation and resilience throughout life. </p>
<p>While there are benefits to being physically and socially active at any age, some research shows the <a href="https://doi.org/10.1016/j.smhs.2019.08.006">payoff from those gains can be higher</a> after age 40 when the body’s metabolism slows, risk factors increase and cognitive reserve becomes even more essential to help protect against <a href="https://doi.org/10.1212/WNL.0000000000007003">cognitive decline</a>.</p>
<p>If making lifestyle changes means you can watch your child navigate adulthood, stroll 20 blocks to your favourite café every day and continue to live in your own home, perhaps walking the daily 10,000 steps, changing diets and keeping your friendship network strong is worthwhile. At worst, you’ll be healthier and more independent with or without dementia. At best, you might completely avoid dementia and other major diseases and keep living your best possible life.</p><img src="https://counter.theconversation.com/content/218003/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laura Middleton receives funding from the Public Health Agency of Canada and the Canadian Institutes of Health Research.</span></em></p><p class="fine-print"><em><span>Saskia Sivananthan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Lifestyle-related dementia risks are complex, with factors like sleep, exercise, diet and social contact interacting with things like cognitive reserve, neuroplasticity and inflammation in the body.Saskia Sivananthan, Affiliate Professor, Department of Family Medicine, McGill UniversityLaura Middleton, Assistant Professor, Department of Kinesiology, University of WaterlooLicensed as Creative Commons – attribution, no derivatives.