tag:theconversation.com,2011:/fr/topics/pnas-journal-4832/articlesPNAS (journal) – The Conversation2016-10-24T19:03:27Ztag:theconversation.com,2011:article/674102016-10-24T19:03:27Z2016-10-24T19:03:27ZWhat wind, currents and geography tell us about how people first settled Oceania<figure><img src="https://images.theconversation.com/files/142940/original/image-20161024-28380-y533y2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Looks like paradise – but how did the first people get there?</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/thegef/7838027336">Global Environment Facility</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Just look at a map of Remote Oceania – the region of the Pacific that contains Hawaii, New Zealand, Samoa, French Polynesia and Micronesia – and it’s hard not to wonder how people originally settled on these islands. They’re mostly small and located many hundreds to thousands of kilometers away from any large landmass as well as from each other. As our species colonized just about every region of the planet, these islands seem to be the last places our distant ancestors reached. </p>
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<p>A comprehensive body of <a href="http://dx.doi.org/10.1080/15564894.2012.726941">archaeological</a>, <a href="http://doi.org/10.1038/35016575">linguistic</a>, <a href="http://www.cambridge.org/us/academic/subjects/archaeology/archaeology-asia-sub-saharan-africa-and-pacific/evolution-polynesian-chiefdoms?format=PB">anthropological</a> and <a href="http://dx.doi.org/10.1080/15564894.2012.761299">genetic</a> evidence suggests that people started settling there about 3,400 years before present (BP). While we have a relatively clear picture of when many of the major island groups were colonized, there is still considerable debate as to precisely where these settlers originated and the strategies and trajectories they used as they voyaged.</p>
<p>In new experiments, my colleagues and I <a href="http://doi.org/10.1073/pnas.1612426113">investigated how environmental variability and Oceania’s geographical setting</a> would have influenced the colonization process. We built computer seafaring simulations and analyzed wind, precipitation and land distribution data over this region of the Pacific. We wanted to understand how seasonal and climate variability in weather and currents might lead to some potential routes being favored over others. How would these factors, including the periodic El Niño and La Niña patterns, affect even the feasibility of different sailing strategies? Did they play a role in the puzzling 2,000-year pause we see in eastward expansion? Could they have provided incentives to migration?</p>
<h2>Standing questions about Oceania’s settlement</h2>
<p>While the archaeological record contains no concrete information on the sailing capabilities of these early voyagers, their navigational prowess is undeniable. Settlement required trips across thousands of kilometers of open ocean toward very small targets. Traditional Pacific vessels such as double-hulled voyaging canoes and outrigger canoes would be able to make these potentially harrowing journeys, but at this point we have no way of knowing what kind of boat technology those early settlers used.</p>
<p>And <a href="https://books.google.com.na/books/about/Pacific_Archaeology_Assessments_and_Pros.html?id=K7bWAAAACAAJ&hl=en">colonization occurred in the opposite direction</a> of mean winds and currents, which in this area of the Pacific flow on average from east to west. Scientists think the pioneers came from west to east, with western Melanesia and eastern Maritime Southeast Asia being the most likely source areas. But there’s still considerable debate as to exactly where these settlers came from, where they traveled and how.</p>
<p>Among the many intriguing aspects of the colonization process is the fact that it occurred in two rapid bursts separated by an almost 2,000-year-long hiatus. Starting around 3,400 BP, the region between the source areas and the islands of Samoa and Tonga was mostly occupied over a period of about 300 years. Then there was a pause in expansion; regions farther to the east such as Hawaii, Rapa Nui and Tahiti were only colonized sometime between about 1,100 and 800 BP. New Zealand, to the west of Samoa and Tonga but located far to the south, was occupied during this second expansion period. What might have caused that millennia-long lag?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/142936/original/image-20161024-28382-nwwo25.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/142936/original/image-20161024-28382-nwwo25.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/142936/original/image-20161024-28382-nwwo25.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/142936/original/image-20161024-28382-nwwo25.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/142936/original/image-20161024-28382-nwwo25.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/142936/original/image-20161024-28382-nwwo25.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/142936/original/image-20161024-28382-nwwo25.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/142936/original/image-20161024-28382-nwwo25.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Contemporary replica of a waʻa kaulua, a Polynesian double-hulled voyaging canoe.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/beautifulcataya/2152404824">Shihmei Barger 舒詩玫</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Simulating sailing conditions</h2>
<p>The goal of our simulations was to take into account what we know about the real-world sailing conditions these intrepid settlers would have encountered at the time they were setting out. We know the general sailing performance of traditional Polynesian vessels – how fast these boats move given a particular wind speed and direction. We ran the simulation using observed present-day wind and current data – our assumption was that today’s conditions would be very close to those from 3,000 years ago and offer a better representation of variability than paleoclimate models.</p>
<p>The simulations compute how far one of these boats would have traveled daily based on winds and currents. We simulated departures from several different areas and at different times of year.</p>
<p>First we considered what would happen if the boats were sailing downwind; the vessels have no specified destination and are allowed to sail only in the direction in which the wind is blowing. Then we ran directed sailing experiments; in these, the boats are still influenced by currents and winds, but are forced to move a minimum daily distance, no matter the environmental conditions, toward a predetermined target. We still don’t know what type of vessels were used or how the sailors navigated; we just ran the model assuming they had some way to voyage against the wind, whether via sails or paddling.</p>
<p>One goal of our analysis was to describe how variations in winds and precipitation associated with the annual seasons and with the El Niño and La Niña weather patterns could have affected voyaging. We focused on conditions that would have favored or motivated movement from west to east, opposite to the mean winds, but in the general direction of the real migratory flow.</p>
<p>We also used land distribution data to determine “shortest hop” trajectories. These are the routes that would be formed if eastward displacement took place by a sequence of crossings in which each individual crossing always reaches the closest island to the east of the departure island.</p>
<h2>What did the environmental data suggest?</h2>
<p>After conducting thousands of voyaging simulations and calculating hundreds of shortest-hop trajectories, patterns started to emerge.</p>
<p>While the annually averaged winds in the region are to the west, there is significant variability, and eastward winds blow quite frequently in some seasons. The occurrence and intensity of these eastward winds increase during El Niño years. So downwind sailing, especially if conducted during particular times of the year (June-November in areas north of the equator and December-February in the Southern Hemisphere), can be an effective way to move eastward. It could be used to reach islands in the region of the first colonization pulse. Trips by downwind sailing become even more feasible under El Niño conditions.</p>
<p>Though many do believe early settlers were able to sail efficiently against the wind, our simulations suggest that even just following the winds and currents would be one way human beings conceivably could have traveled east in this area. (Moving eastward in the area east of Samoa does require sailing against the wind, though.)</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/142943/original/image-20161024-28376-1dkhihv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/142943/original/image-20161024-28376-1dkhihv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/142943/original/image-20161024-28376-1dkhihv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=622&fit=crop&dpr=1 600w, https://images.theconversation.com/files/142943/original/image-20161024-28376-1dkhihv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=622&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/142943/original/image-20161024-28376-1dkhihv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=622&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/142943/original/image-20161024-28376-1dkhihv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=782&fit=crop&dpr=1 754w, https://images.theconversation.com/files/142943/original/image-20161024-28376-1dkhihv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=782&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/142943/original/image-20161024-28376-1dkhihv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=782&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Filled red lines depict all shortest-hop paths with starts from central and southern Philippines, Maluku and Solomon departure areas.</span>
<span class="attribution"><span class="source">Using seafaring simulations and shortest-hop trajectories to model the prehistoric colonization
of Remote Oceania. Montenegro et al., PNAS 2016 doi:10.1073/pnas.1612426113</span></span>
</figcaption>
</figure>
<p>Our shortest-hop analysis points to two “gateway islands” – eastward expansion into large areas of Oceania would require passage through them. Movement into Micronesia would have to go through Yap. Expansion into eastern Polynesia would mean traveling through Samoa. This idea of gateway islands that would have to be colonized first opens new possibilities for understanding the process of settling Oceania.</p>
<p>As for that 2,000-year-long pause in migration, our simulation provided us with a few ideas about that, too. The area near Samoa is marked by an increase in distance between islands. And no matter what time of year, El Niño or not, you need to move against the wind to travel eastward around Samoa. So it makes sense that the pause in the colonization process was related to the development of technological advances that would allow more efficient against-the-wind sailing.</p>
<p>And finally, we think our analysis suggests some incentives to migration, too. In addition to changes to wind patterns that facilitate movement to the east, the El Niño weather pattern also causes drier conditions over western portions of Micronesia and Polynesia every two to seven years. It’s possible to imagine El Niño leading to tougher conditions, such as crop-damaging drought. El Niño weather could simultaneously have provided a reason to want to strike out for greener pastures and a means for eastward exploration and colonization. On the flip side, changes in winds and precipitation associated with La Niña could have encouraged migration to Hawaii and New Zealand.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/142942/original/image-20161024-28405-fvteiu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/142942/original/image-20161024-28405-fvteiu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/142942/original/image-20161024-28405-fvteiu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=421&fit=crop&dpr=1 600w, https://images.theconversation.com/files/142942/original/image-20161024-28405-fvteiu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=421&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/142942/original/image-20161024-28405-fvteiu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=421&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/142942/original/image-20161024-28405-fvteiu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=529&fit=crop&dpr=1 754w, https://images.theconversation.com/files/142942/original/image-20161024-28405-fvteiu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=529&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/142942/original/image-20161024-28405-fvteiu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=529&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Synthesis of results. Filled and dashed arrows refer to crossings that, according to simulations, are viable under downwind and directed sailing, respectively.</span>
<span class="attribution"><span class="source">Using seafaring simulations and shortest-hop trajectories to model the prehistoric colonization
of Remote Oceania. Montenegro et al., PNAS 2016 doi:10.1073/pnas.1612426113</span></span>
</figcaption>
</figure>
<p>Overall, <a href="http://doi.org/10.1073/pnas.1612426113">our results</a> lend weight to various existing theories. El Niño and La Niña have been proposed as potential migration influences before, but we’ve provided a much more detailed view in both space and time of how this could have taken place. Our simulations strengthen the case for a lack of technology being the cause for the pause in migration, and downwind sailing as a viable strategy for the first colonization pulse 3,400 BP.</p>
<p>In the future, we hope to create new models – turning to time-series of environmental data instead of the statistical descriptions we used this time – to see if they produce similar results. We also want to develop experiments that would evaluate sailing strategies not in the context of discovery and colonization but of exchange networks. Are the islands along “easier” pathways between distant points also places where the archaeology shows a diverse set of artifacts from different regions? There’s still plenty to figure out about how people originally undertook these amazing voyages of exploration and expansion.</p><img src="https://counter.theconversation.com/content/67410/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alvaro Montenegro receives funding from Ohio State University, Sao Paulo Research Foundation and Univ. Estadual Paulista (Unesp). </span></em></p>Researchers ran computer simulations that take into account environmental variability and geographical setting to investigate how early explorers made it to these tiny, remote islands in the Pacific.Alvaro Montenegro, Assistant Professor of Geography and Director Atmospheric Sciences Program, The Ohio State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/577502016-04-13T19:15:40Z2016-04-13T19:15:40ZThe evolutionary origins of laughter are rooted more in survival than enjoyment<figure><img src="https://images.theconversation.com/files/118585/original/image-20160413-10808-68q2ax.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Kletr/shutterstock.com</span></span></figcaption></figure><p>Laughter plays a crucial role in every culture across the world. But it’s not clear why laughter exists. While it is evidently an inherently social phenomenon – people are up to <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0310.1989.tb00536.x/abstract;jsessionid=623CFFB06B6CBF7E8912B67215456C75.f01t01">30 times more likely to laugh in a group</a> than when alone – laughter’s function as a form of communication remains mysterious.</p>
<p>A new <a href="http://www.pnas.org/content/early/2016/04/05/1524993113.short?rss=1">study</a> published in the Proceedings of the National Academy of Sciences, and involving a large group of researchers led by Gregory Bryant from UCLA, suggests that laughter may indicate to listeners the friendship status of those laughing. The researchers asked listeners to judge the friendship status of pairs of strangers and friends based on short snippets of their simultaneous laughter. Drawn from 24 different societies, they found that listeners were able to reliably distinguish friends from strangers, based on specific acoustic characteristics of the laughter.</p>
<p>In order to unravel how this is possible and what the true meaning of laughter is, we need to delve back into its early origins.</p>
<h2>Laughter’s evolutionary past</h2>
<p>Spontaneous laughter, which is unintentionally triggered by conversation or events, emerges in the first few months of life, even in children who are deaf or blind. Laughter not only transcends human cultural boundaries, but species boundaries, too: it is present in a similar form in other great apes. In fact, the evolutionary origins of human laughter can be traced back to between <a href="http://www.cell.com/current-biology/fulltext/S0960-9822(09)01129-4">10 and 16m years ago</a>.</p>
<p>While laughter has been linked to <a href="https://books.google.co.uk/books?hl=en&lr=&id=Yi42CwAAQBAJ&oi=fnd&pg=PA159&ots=6gmryAyBT6&sig=bPk1yaxOaklgSpPt-H_q3EzDXaY#v=onepage&q&f=false">higher pain tolerance and the signalling of social status</a>, its principal function appears to be creating and deepening social bonds. As our ancestors began to live in larger and more complex social structures, the quality of relationships became <a href="https://www.researchgate.net/profile/Joan_Silk/publication/6017732_Social_Components_of_Fitness_in_Primate_Groups/links/551566970cf2b5d6a0e9ada9.pdf">crucial to survival</a>. The process of evolution would have favoured the development of cognitive strategies that helped form and sustain these cooperative alliances. </p>
<p>Laughter probably evolved from laboured breathing during play such as tickling, which encourage cooperative and competitive behaviour in young mammals. This expression of the shared arousal experienced through play may have been effective in strengthening positive bonds, and laughter has indeed been shown to prolong the length of play behaviours in both children and chimpanzees, and to directly elicit both conscious and unconscious <a href="https://books.google.co.uk/books?hl=en&lr=&id=T3wVqKtF33gC&oi=fnd&pg=PA175&ots=tuafGr39km&sig=RfLHJZqga8YftJXexTwLtpR_B5U#v=onepage&q&f=false">positive emotional responses</a> in human listeners.</p>
<figure>
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<h2>Laughter as a social tool</h2>
<p>The emergence of laughter and other primal vocalisations was at first intimately tied to how we felt: we only laughed when aroused in a positive way, just as we cried only when distressed, or roared only when angry. The key development came with the ability to vocalise voluntarily, without necessarily experiencing some underlying pain, rage, or positive emotion. This <a href="http://authors.elsevier.com/a/1SlJe4sIRu%7EfdE">increased vocal control</a>, made possible as our brains grew more complex, was ultimately vital in the development of language. But it also allowed us to consciously mimic laughter (and other vocalisations), providing a deceptive tool to artificially quicken and expand social bonds – and so increase survival odds.</p>
<p>The idea that this volitional laughter also has an evolutionary origin is reinforced by the presence of similar behaviour in adult chimpanzees, who produce <a href="https://www.researchgate.net/profile/Kim_Bard/publication/50224801_Aping_Expressions_Chimpanzees_Produce_Distinct_Laugh_Types_When_Responding_to_Laughter_of_Others/links/00b7d526e20372f681000000.pdf">laugh imitations</a> in response to the spontaneous laughter of others. The fake laughter of both chimpanzees and humans develops during childhood, is acoustically distinct from its spontaneous counterpart, and serves the same social bonding function.</p>
<p>Today, both spontaneous and volitional laughter are prevalent in almost every aspect of human life, whether sharing a joke with a mate or during polite chitchat with a colleague. However, they’re not equivalent in the ear of beholder. Spontaneous laughter is characterised by higher pitch (indicative of genuine arousal), shorter duration and shorter laugh bursts compared to volitional laughter. Researchers recently <a href="http://www.ehbonline.org/article/S1090-5138(14)00035-X/fulltext?mobileUi=0">demonstrated</a> that human listeners can distinguish between these two laugh types. Fascinatingly, they also showed that if you slow down and adjust the pitch of volitional laughter (to make it less recognisable as human) listeners can distinguish it from animal vocalisations, whereas they cannot do the same for spontaneous laughter, whose acoustic structure is far more similar to nonhuman primate equivalents.</p>
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<img alt="" src="https://images.theconversation.com/files/118586/original/image-20160413-25397-1eyxyrm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/118586/original/image-20160413-25397-1eyxyrm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/118586/original/image-20160413-25397-1eyxyrm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/118586/original/image-20160413-25397-1eyxyrm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/118586/original/image-20160413-25397-1eyxyrm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/118586/original/image-20160413-25397-1eyxyrm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/118586/original/image-20160413-25397-1eyxyrm.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">Look who’s laughing now.</span>
<span class="attribution"><span class="source">dariagarnik/shutterstock.com</span></span>
</figcaption>
</figure>
<h2>Friend or stranger?</h2>
<p>It’s this audible difference that is demonstrated in the paper by Bryant and his colleagues. Friends are more likely to produce spontaneous laughs, while strangers who lack an established emotional connection are more likely to produce volitional laughter.</p>
<p>The fact that we can accurately perceive these distinctions means that laughter is to some extent an honest signal. In the neverending evolutionary arms race, adaptive strategies for deception tend to co-evolve with strategies to detect that deception. The acoustic characteristics of authentic laughter are therefore useful cues to the bonds between and status of members of a group. This is something that may have aided decision-making in our evolutionary past. </p>
<p>However, the study found that judgement accuracy was on average only 11% higher than chance. Perhaps this is partially because some strangers may have produced spontaneous laughs and some friends volitional laughs, but it’s clear that imitating authentic emotional laughter is a valuable deceptive tool for social lubrication. One need only witness the contagious effects of <a href="http://www.sciencedirect.com/science/article/pii/S0022103104001192">canned laughter</a> to see how true this is.</p>
<p>In the complex reality of modern human social interaction, laughs are often aromatic blends of the full-bodied spontaneous and dark but smooth volitional types, further blurring the boundaries. Regardless, the goal is the same and we will most likely find ourselves becoming fonder of those we share the odd chuckle with.</p>
<p>John Cleese once <a href="http://www.openculture.com/2015/04/john-cleese-explores-the-health-benefits-of-laughter-yoga.html">said</a>: “Laughter connects you with people. It’s almost impossible to maintain any kind of distance or any sense of social hierarchy when you’re just howling with laughter.” He might just have hit the nail on the head – even when we’re faking it.</p><img src="https://counter.theconversation.com/content/57750/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jordan Raine 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>Why do we laugh? Evolutionarily speaking, it’s so we could survive – and similar rules apply today.Jordan Raine, PhD Researcher, Nature and Function of Human Nonverbal Vocalisations , University of SussexLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/571162016-04-04T20:08:45Z2016-04-04T20:08:45ZRegenerating body parts: how we can transform fat cells into stem cells to repair spinal disc injuries<figure><img src="https://images.theconversation.com/files/117240/original/image-20160404-18648-lw7d5q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Injecting stem cells to repair damaged tissue isn't a new concept, but this method appears safer than others. </span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-394470439/stock-photo-young-girl-with-back-pain-close-up.html?src=1PMDrXUik5Ojl67b6oJDZQ-7-22">Africa Studio/Shutterstock</a></span></figcaption></figure><p>We often hear about the next big thing in stem cell therapy, though few of these promises eventuate or are backed up by evidence. </p>
<p>Well, we think we’re close to a genuine breakthrough in stem cell therapy, based on new research published today in <a href="http://www.pnas.org/">Proceedings of the National Academy of Sciences</a>.</p>
<p>We have developed a stem cell technique capable of regenerating any human tissue damaged by injury, disease or ageing. </p>
<p>The new technique, which reprograms bone and fat cells into <a href="http://www.itek.com.au/portfolio/health/item/small-molecule-induced-neural-stem-cells.html">induced multipotent stem cells</a> (iMS), has successfully repaired bones and muscles in mice. Human trials are set to begin next year.</p>
<h2>How the technique works</h2>
<p>Injecting stem cells to repair damaged tissue is not a new concept. Every time someone receives a bone marrow transplant, they have in fact received blood stem cells to rescue their blood production. </p>
<p>But bone marrow is easy to extract and blood is constantly replaced. Therefore, blood stem cells are relatively easy to source. </p>
<p>This is not the case if you need stem cells to repair damage to muscles, cartilage or organs such as the heart and brain. These stem cells are not easy to extract and their turnover is low.</p>
<p>If stem cells are hard to extract, another option is to reprogram mature cells from other parts of the body that are relatively easy to extract. We have developed a method that converts fat or bone cells, which are relatively easy to extract, into induced multipotent stem cells. </p>
<p>This method involves culturing fat or bone cells with a drug called <a href="http://www.australianprescriber.com/magazine/33/3/89/95/drug/914/azacitidine">Azacitidine</a> and a naturally occurring growth factor called platelet-derived growth factor.</p>
<p>Azacitidine is used to treat blood disorders and has the ability to relax the hard-wired gene expression patterns that make a fat cell a fat cell or a bone cell a bone cell. </p>
<p>We think the combination of erasing the cell’s memory with Azacitidine and forcing the cell to proliferate with the growth factor are key to converting fat and bone cells into induced multipotent stem cells.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/117237/original/image-20160404-18622-1e4p281.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/117237/original/image-20160404-18622-1e4p281.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=848&fit=crop&dpr=1 600w, https://images.theconversation.com/files/117237/original/image-20160404-18622-1e4p281.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=848&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/117237/original/image-20160404-18622-1e4p281.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=848&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/117237/original/image-20160404-18622-1e4p281.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1066&fit=crop&dpr=1 754w, https://images.theconversation.com/files/117237/original/image-20160404-18622-1e4p281.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1066&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/117237/original/image-20160404-18622-1e4p281.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1066&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="attribution"><span class="source">UNSW.</span></span>
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<h2>The quest for tissue regeneration</h2>
<p>The new technique is similar to the limb regeneration of the salamander, which can repair multiple tissue types, depending on which body part needs replacing.</p>
<p>In 2006, Japanese Nobel Prize-winning stem cell researcher Shinya Yamanaka identified a small number of genes that could reprogram skin cells from mice into immature stem cells, which could grow into all types of cells in the body. </p>
<p>However, these induced pluripotent stem (iPS) cells, like embryonic stem cells, which are derived from early embryos, are not suitable as a stem cell therapy because they can form tumours rather than repairing damaged tissue. </p>
<p>Since then, scientists have identified different combinations of genes that can reprogram skin or other cells into tissue-specific stem cells that only make cells of a single type of tissue. </p>
<p>A drawback with these reprogramming methods is the use of viral elements to force gene expression. Researchers use a virus as a mechanism to inject the gene into the cell. </p>
<p>Multipotent stem cells, in contrast, are produced without using any viral elements. They can regenerate damaged tissues without making unwanted tissues or tumours at the site of transplantation. </p>
<h2>What did we find?</h2>
<p>We have reprogrammed mouse bone cells into induced multipotent stem cells and injected these cells into mice with damaged bone and muscle. </p>
<p>We were astounded by the ability of these induced multipotent stem cells to regenerate these damaged tissues and also generate their own blood supply to carry nutrients to these developing tissues. </p>
<p>The transplanted cells appear to follow instructions from adjacent cells and divide and mature in an orderly fashion.</p>
<h2>Safety and efficacy</h2>
<p>We are still investigating the safety and regenerative potential of human-induced multipotent stem cells. </p>
<p>We have injected human-induced multipotent stem cells, made by reprogramming human fat cells, into our animal models of tissue injury. We are monitoring signals from these cells and know they are retained at the site of injection. </p>
<p>In a few months, we will retrieve tissues from these mice to measure the contribution from transplanted human-induced multipotent stem cells to tissue regeneration in mice.</p>
<p>We need evidence of robust tissue regeneration and the absence of any unwanted tissues or tumours at these sites before commencing human trials.</p>
<h2>Clinical applications</h2>
<p>The process of human induced multipotent stem cell production is free of animal products and is being developed to meet manufacturing standards appropriate for human cell transplantation. </p>
<p>Our initial clinical focus will be using induced multipotent stem cells either as a stand-alone treatment or with spinal implants to treat <a href="http://www.mayfieldclinic.com/PE-DDD.htm">degenerative disc disease</a> towards the end of 2017. </p>
<p>Low back and neck pain is frequently associated with degenerative disc disease and is a major cause of disability, affecting millions of people globally with crippling physical and economic costs.</p>
<p>Our aim is to use induced multipotent stem cells to regenerate discs to retain the flexibility of the native spine or to stabilise spinal implants by helping them fuse with adjacent bone.</p>
<h2>Next steps</h2>
<p>We need further research to understand how mouse- and human-induced multipotent stem cells respond to signals from damaged tissues. It will also be important know how long induced multipotent stem cells remain at sites of transplantation and retain their ability to proliferate and make new tissues. </p>
<p>Nevertheless, this efficient virus-free method of generating tissue regenerative stem cells brings us a step closer to realising stem cell therapy for repairing tissue injury in the human body.</p><img src="https://counter.theconversation.com/content/57116/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Pimanda is employed by UNSW Australia and the Prince of Wales Hospital and receives funding from the National Health and Medical Research Council. </span></em></p><p class="fine-print"><em><span>Vashe Chandrakanthan receives funding from the NHMRC. </span></em></p><p class="fine-print"><em><span>Ralph Mobbs 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>We have developed a new stem cell technique capable of regenerating any human tissue damaged by injury, disease or ageing.John Pimanda, Associate Professor of Medicine and Stem Cell Biology, UNSW SydneyRalph Mobbs, Neurosurgeon at the Prince of Wales Hospital; Conjoint Lecturer, UNSW SydneyVashe Chandrakanthan, Researcher, regenerative medicine, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/449462015-07-20T19:23:09Z2015-07-20T19:23:09ZMusical training can accelerate brain development and help with literacy skills<figure><img src="https://images.theconversation.com/files/89064/original/image-20150720-12567-8vzbxj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What's happening in world-famous cellist Yo-Yo Ma's brain?</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-196322336/stock-photo-human-brain-recording-information-with-headphones.html?src=2QzCfFvUytEgPLWOjc4IWg-1-10">Cello by Shutterstock</a></span></figcaption></figure><p>The notion that musical training can have positive effects on cognitive functions other than music has long been a source of interest. <a href="https://books.google.co.uk/books/about/Relationships_Between_Intelligence_Schol.html?id=Pt65AAAAIAAJ&redir_esc=y">Research first emerged</a> at the beginning of the 20th century. Standardised assessments of IQ and musical ability suggested the two were correlated – and <a href="http://www.tandfonline.com/doi/abs/10.1080/08856559.1942.10534660">it was thought</a> that participation in musical training could improve IQ. </p>
<p>Recently, research has shifted focus from effects on musical training on global intelligence and instead focuses on benefits to specific skills and tasks in individuals.</p>
<p>Musical training has shown to lead to improvements in a wide variety of different skills, including <a href="http://www.ncbi.nlm.nih.gov/pubmed/21315092">memory</a> and <a href="http://www.sciencedirect.com/science/article/pii/S0885200600000508">spatial learning</a> for example. In addition, language skills such as <a href="http://www.nature.com/nature/journal/v396/n6707/abs/396128a0.html">verbal memory</a>, <a href="http://www.brainmusic.org/EducationalActivities/Tallal_development2006.pdf">literacy</a> and <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0003566">verbal intelligence</a> have been shown to strongly benefit from musical training.</p>
<p>Musicians are <a href="http://www.jneurosci.org/content/29/45/14100.full">also more adept at processing speech</a> in environments where there are large amounts of background noise, possess a greater propensity for processing auditory signals that are <a href="http://www.ncbi.nlm.nih.gov/pubmed/20691672">in some way degraded</a> and show an advantage over their musically naive counterparts when it comes to pitch detection in <a href="http://www.ncbi.nlm.nih.gov/pubmed/16494681">both music and language</a>. Recent advances in technologies have also allowed researchers to probe into the neural (functional, structural and electrophysiological) underpinnings of these adaptations.</p>
<h2>The brain responds</h2>
<p>A <a href="http://www.pnas.org/content/early/2015/07/15/1505114112">new study</a>, just published in the Proceedings of the National Academy of Sciences, aimed to assess neurodevelopment in adolescence and the impact that certain forms of experience, such as musical training, could have on this process. </p>
<p>Neuro-physiological methods were adopted to measure subcortical and cortical responses to speech in the brains of two groups of adolescents in a high school in the Chicago area. One group took part in group musical training and one group took part in a Junior Reserve Officer Training Corps programme. Enrolment on to one of these two programmes was part of the curriculum of the schools with which the lead researcher, Adam Tierney of Northwestern University, worked.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/89071/original/image-20150720-12527-g4ss59.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/89071/original/image-20150720-12527-g4ss59.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/89071/original/image-20150720-12527-g4ss59.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/89071/original/image-20150720-12527-g4ss59.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/89071/original/image-20150720-12527-g4ss59.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/89071/original/image-20150720-12527-g4ss59.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/89071/original/image-20150720-12527-g4ss59.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">
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<span class="caption">March of progress.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-191160056/stock-photo-shafter-ca-may-the-shafter-high-school-band-brass-section-plays-with-enthusiasm-on-a.html?src=jhS2vhvIoEklfwxqUv00nw-1-2">Richard Thornton/Shutterstock.com</a></span>
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<p>The method allowed Tierney and his colleagues to assess how their participants’ brains encoded speech before and after three years of taking part in the two different types of training. Language skills were also assessed using a phonological awareness task – which included asking the adolescents to create a new word by dropping a syllable or unit of sound from a spoken word. They were also assessed using a phonological memory task, in which they had to repeat back lists of digits or non-English words, and a rapid naming task, where they had to read aloud a list of letters or digits as quickly and accurately as they could.</p>
<p>At adolescence the brain is not fully developed and specific areas are yet to mature, which makes this an interesting age to do these tests. The results showed that both groups made improvements in all of the language tasks, as would be expected over this period in their development – but, in addition, the degree of improvement was larger in the phonological awareness task for the group who had undergone musical training. </p>
<p>The methods used allowed the researchers to track the level of neural development present in the brains of the participants. Through this they were then able to measure the usual time course of changes that occurred at this stage in development and assess any alterations due to participation in either the music training, or officer training.</p>
<p>The researchers observed the normal brain development that occurs at this age in both groups. However, for those who participated in musical training the period of time during which regions of the brain responsible for auditory processing were developing was extended in comparison to those that did the officer training. The musically trained groups also showed an accelerated time course for reaching adult cortical development. The results therefore suggest that participation in musical training can accelerate brain development and that this can benefit literacy skills.</p>
<h2>Music and language</h2>
<p>Music could potentially function as a training ground for language skills and may potentially offer an effective, economical and enjoyable activity that could help improve language skills in children around the world if employed in schools. Giving adolescents musical training could help kick-start and accelerate maturation of their brains.</p>
<p>These advantages may also have potential to provide enhancements to a wider range of skills, such as the learning of a second language. The study suggests that musical training could help prolong the window of time in which the brain is developing and is able to deal with complex auditory input, which in turn could make second language learning more achievable to people who otherwise may struggle. </p>
<p>It is important to note however, that although musical training was shown to produce benefits for the phonological awareness language tasks, for the other two tests of phonological memory and rapid naming, no difference between the two groups of adolescents was found. This suggests that although musical training does have the potential to enhance some forms of language skills, there are areas that it does not improve.</p><img src="https://counter.theconversation.com/content/44946/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amy Spray 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>Music is good for the brain – and we’re now discovering how it helps our cognition.Amy Spray, PhD candidate, University of LiverpoolLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/431512015-06-15T19:02:36Z2015-06-15T19:02:36ZMud pies and green spaces – why children do better when they can get outdoors<figure><img src="https://images.theconversation.com/files/85030/original/image-20150615-5812-14tol0k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Good reasons to get outdoors. </span> <span class="attribution"><span class="source">Playing outdoors via Matt Jeppson/www.shutterstock.com</span></span></figcaption></figure><p>The first warm weather here in the UK generally means a few things – the impending start of tennis at Wimbledon, school examination time, and the smell of cut grass. Inevitably, pupils and teachers start to wish they were outdoors and not stuck in a classroom. There is now a growing body of evidence why teachers should respond to these urges and incorporate outdoor places into their teaching and the school day more widely. </p>
<p>A <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1503402112">new study</a> published in Proceedings of the National Academy of Sciences by a team of researchers from Spain, Norway, and the US found that time spent near or in green places, especially those in and around schools, can improve learners’ cognitive development. Payam Dadvand and colleagues found that pupils’ ability in memory tasks and to maintain attention improved over time if their schools had green spaces on their campus and nearby. </p>
<p>The study involved 2,500 children aged seven to ten in Barcelona, who were tested every three months over a 12-month period. The researchers found small but significant improvements in “working memory”, “superior working memory” and “attentiveness” in pupils with green areas near and in their schools. Importantly, in this rigorous study, the effects of greenness were found regardless of the socio-economic background and education of parents. </p>
<p>The Spanish-led team sought mainly to explain and explore the medical reasons for their findings. It could be, the authors argue, that with green spaces children are less exposed to traffic and the kinds of pollutants that are likely to negatively influence development, especially at the younger ages. There are also possible explanations such as the reduction of noise, the likelihood that children will be more active, and, the presence of <a href="https://theconversation.com/parasites-harder-to-swallow-but-we-already-take-probiotics-18574">natural microbes</a> – which I think we can take to mean that “making mud pies” is good for your development.</p>
<h2>Good for well-being</h2>
<p>We have some way to go to grasp the other knock-on effects of green space. For example, we know from <a href="http://www.greenexercise.org/Papers_Reports.html">other studies</a> that exercising in green spaces and greenness in one’s neighbourhood improves mental health through lowering the risk of anxiety and depression. It could be that happier children are better able to learn too. </p>
<p>Finnish psychologist Kalevi Korpela has done useful <a href="https://www.researchgate.net/profile/Henk_Staats/publication/259841070_Korpela_K.__Staats_H._%282014%29._The_restorative_qualities_of_being_alone_with_nature._In_Coplan__J.C._Bowker_%28eds.%29_The_Handbook_of_Solitude/links/54e4ad300cf22703d5bf10d8.pdf">work in this area</a>. He found that spending “time out”, time alone or times in one’s favourite place in nature have positive effects: reducing stress levels, muscle tension, heart rate and other physiological factors. It has been argued that being alone in nature is “restorative” for us, allowing us to clear our minds, and deal with our troubles, and feel better about ourselves. It even appears that the more stressed you are, the more likely that this solo time in nature will be the prescription required.</p>
<p>Different “dosages” of green space can have a range of different effects on different kinds of people that are only recently being uncovered. <a href="http://www.gla.ac.uk/news/headline_402984_en.html">Richard Mitchell’s work</a> in Scotland has found that access to green or recreational areas led to a narrowing of the differences between rich and poor on some measures around mental health. <a href="http://ac.els-cdn.com/S0272494415000195/1-s2.0-S0272494415000195-main.pdf?_tid=1160242c-1051-11e5-9639-00000aacb35d&acdnat=1434037787_01431401551883dd9b3e5cc10047a8ce">Another recent study</a> looked at how even visually experiencing nature – in this case looking <a href="https://theconversation.com/virtual-nature-makes-us-feel-good-even-if-its-farmville-21099">at photos and videos</a> – may increase one’s disposition to cooperate and to engage in certain actions. <a href="http://www.fullerlab.org/wp-content/uploads/2015/04/Shanahan-et-al-2015a.pdf">For some,</a> the type and duration of the required “dose” of green space in our increasingly urbanised settings is an important consideration as we move towards deeper understandings of its effects.</p>
<h2>Greening the curriculum</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/85031/original/image-20150615-5832-vxcwgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/85031/original/image-20150615-5832-vxcwgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=389&fit=crop&dpr=1 600w, https://images.theconversation.com/files/85031/original/image-20150615-5832-vxcwgm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=389&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/85031/original/image-20150615-5832-vxcwgm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=389&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/85031/original/image-20150615-5832-vxcwgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=489&fit=crop&dpr=1 754w, https://images.theconversation.com/files/85031/original/image-20150615-5832-vxcwgm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=489&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/85031/original/image-20150615-5832-vxcwgm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=489&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">Making learning more fun.</span>
<span class="attribution"><span class="source">Children outdoors via Andresr/www.shutterstock.com</span></span>
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</figure>
<p>Lacking in much of the research reported upon above is any in-depth consideration of the way people’s engagement with nature and green spaces are influenced by society and culture, and by the types of natural places they go to. In education, we need to do more work to understand better how pupils are using green spaces for travel to and from school, during playtime, and within the curriculum. </p>
<p>Given the wider literature on the effects of having green spaces nearby, we might expect that engaging in more purposeful activity in nature for educational ends (rather than merely looking at it or having it nearby) will boost pupil’s achievements and attainment. In <a href="http://www.snh.org.uk/pdfs/publications/commissioned_reports/779.pdf">my own research</a>, funded by a consortium led by Scottish Natural Heritage in Scotland, we looked at the provision of outdoor learning opportunities for children. </p>
<p>Our study used teacher’s reports on pupil’s experience of over 1,000 lessons outdoors. We noted that outdoor educational provision had increased between 2006 and 2014. But, it was striking that outdoor experiences in green areas (such as parks, gardens, wildlife areas and woodland) were comprehensively seen by teachers as important for both increasing learner engagement and enhancing pupils’ “challenge and enjoyment”. This finding seems worthy of further investigation. </p>
<p>It seems that research across many areas and disciplines now needs to be combined to fully understand the green uplift effect in many aspects of education, health, development and well-being, particularly for young people. The majority of us will soon be living in cities worldwide so there are new and important reasons for planning for green space in all local areas but within and around schools and pre-schools. In the meantime, I suggest that we should begin to green our educational provision – and our own backyards and schoolyards are certainly a good place to begin.</p><img src="https://counter.theconversation.com/content/43151/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Greg Mannion works as a Senior Lecturer at University of Stirling.
</span></em></p>New research has shown that living near green spaces can improve children’s cognitive development.Greg Mannion, Senior Lecturer, Director of Post-graduate Research, School of Education, University of StirlingLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/404082015-04-20T20:26:32Z2015-04-20T20:26:32ZFostering before the age of two helps children in institutional care deal better with stress<figure><img src="https://images.theconversation.com/files/78606/original/image-20150420-25694-xptry5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Institutional care for young children can impact on their health later on.</span> <span class="attribution"><span class="source">Sad girl via Yuliya Evstratenko/www.shutterstock.com</span></span></figcaption></figure><p>As human beings we are born helpless and entirely dependent on those who care for us. Most of us are lucky to have had parents or guardians who provided us with food, security and comfort. We form attachment experiences with these caregivers that create a way to develop our social skills and grow up with a sense of purpose and value in the social world.</p>
<p>But some children do not find themselves in the care of a family but rather in the care of an institution. There they are much more likely to experience a lack of responsive and sensitive care. We now know that growing up in such settings has a <a href="http://discovery.ucl.ac.uk/96522/">long-term negative</a> impact on a child’s <a href="http://www.ncbi.nlm.nih.gov/pubmed/20500637">physical and mental health</a>.</p>
<p>Important questions remain about how best to help children recover from the negative effects of being institutionalised. Research with rodents and non-human primates has provided some clues. These animal studies have demonstrated that early maternal deprivation has enduring effects on biological and behavioural responses to stress, such as the functioning of the hyperthalamic-pituitary-adrenal (HPA) axis, a key physiological system that regulates stress hormone production. </p>
<p>It has also been shown that a typically high stress response of rodents who have been maternally deprived <a href="http://sites.oxy.edu/clint/physio/article/EnvironmentalEnrichmentReversestheEffectsofMaternalseperationstress.pdf">can be reversed</a> by an enriched environment during puberty. However, because of the differences between animals and humans, it hasn’t been possible to generalise from animal studies to humans.</p>
<h2>Turning down the stress levels</h2>
<p>A <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1423363112">new US study</a> published in Proceedings of the National Academy of Sciences examined the consequences of early life deprivation on children associated with growing up in an institution. The study, by scientists based at the University of Washington, also looked at the potential for a family caregiving environment to reverse the impact of such early adversity. </p>
<p>The children in the study were abandoned in Romania. They were randomly selected with 43 remaining in institutions in Bucharest and 48 placed in foster family care. These two groups of children were compared with each other and also with another group of 47 children who came from similar backgrounds, but had never been institutionalised. </p>
<p>The scientists measured the impact of these different rearing conditions on the development of the children’s “stress response system”. They did this by measuring the autonomic nervous system and the HPA axis. Because the institutionalised children were placed in foster care at different ages, it was possible to investigate the impact of timing on the development of their “stress response system”.</p>
<p>The researchers found that children who remained in institutional care exhibited significantly blunted biological response to psychosocial stress compared with children who were in foster care. In other words, their stress response systems responded less strongly to a socially challenging task. Overall, children in foster care generally resembled the typically developing children who had never been institutionalised. </p>
<p>These findings provide convincing evidence that the disruption to early caregiving among children who have experienced institutional care can have a negative impact on children’s response to stress later on. However, it is extremely encouraging that by placing children in the care of a foster family, the effects of such early institutionalisation on stress systems can be ameliorated. It will be important to show in future studies that there are also improvements in behaviour and emotional functioning. </p>
<h2>Timing matters</h2>
<p>The researchers also found that the therapeutic effects of the foster care were most evident in children who were fostered before they reached 24 months. They fared much better. For example, the reactivity of the stress hormone, cortisol, was significantly associated with the age of being placed in foster care: the earlier the foster placement the more normal the cortisol response to stress at the age of 12.</p>
<p>The authors have <a href="http://www.ncbi.nlm.nih.gov/pubmed/20331663">previously found</a> that such timing effects have a similar impact on other domains, including attachment. Collectively, these findings lend weight to the notion that there are sensitive periods in human development when it comes to caregiving.</p>
<p>As with any study, there are a number of factors that need to be weighed up when considering the implications of the research. The random allocation of children to foster care or institutional care makes it more likely that both groups were as similar as possible. However, it is less clear why children in the fostered group were placed with families earlier or later. It’s possible the most difficult children who had experienced the most adversity were placed later. If so this would weaken a strong argument for a sensitive period. </p>
<p>A second issue to consider is that that stress response systems may reflect the current environmental demands of where a child is placed. We know that some of these children still remain in the institutions. It remains possible that stress responses could, at least in part, be “recalibrated” by foster care placement – even as these children are entering adolescence – given that this represents a period of particular neurobiological plasticity during which certain brain regions undergo a process of rewiring. </p>
<p>These findings have important implications for policy and practice for <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2814%2961131-4/abstract">children in institutional care</a>. But we should be cautious in generalising these findings to children in the care system in the UK who have experienced abuse and neglect at home. The experience of institutionalisation as an infant is a unique and extreme form of early adversity. However, in this remarkable study the authors have demonstrated the negative impacts in relation to stress responses can be reversed.</p><img src="https://counter.theconversation.com/content/40408/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eamon McCrory has received past and current funding from the Economic and Social Research Council, Waterloo Foundation, Kids Company and the Anna Freud Centre to research impact of early adversity. The views in this article do not reflect those of the research council. </span></em></p><p class="fine-print"><em><span>Essi Viding has received past and current funding from the Economic and Social Research Council, Waterloo Foundation, and Kids Company to research impact of early adversity. The views in this article do not reflect those of the research council. </span></em></p>A new study has shown the impact of institutional care on the way children deal with stress can be reversed if they are fostered early.Eamon McCrory, Professor of Developmental Neuroscience and Psychopathology, UCLEssi Viding, Professor of Developmental Psychopathology, UCLLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/396682015-04-07T05:25:36Z2015-04-07T05:25:36ZOcean ‘dead zones’ are spreading – and that spells disaster for fish<figure><img src="https://images.theconversation.com/files/76942/original/image-20150402-9312-gronyt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fish can suffocate too.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/seadigs/5510111800/in/photolist-oNLgkc-pt8oNT-6S9ojH-mNZfUV-7UeGca-84yb9i-7RLurZ-7RPGGQ-qFr19a-9oW4b7-7jv8Kw-8iMyoy-5aF9zJ-8sKHiS-8sGEbM-9oSVDX-9oSV74-9oW2rW-9oSW7X-9oSXmp-mVXuge-e41QBt-98F53h-9oSWra-k6A4BV-9oW3JC-7wJT2e-dGGSYq-9oULgA-eZnGru-6SdseJ-6Sdtbj-e41QC6-9oY11k-9p27Eh-9oSUJg-9oVXWy-9oVYs9-9oVYVJ-dGHiHd-9p25S5-9oUGrh-2rFxN2-2rKWZs-2rKWrN-i4rsZ1-9oY1iv-9oY28X-2rKT2C-9oXZL8">Bruce Evans</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Falling ocean oxygen levels due to rising temperatures and influence from human activities such as agrochemical use is an <a href="http://news.nationalgeographic.com/2015/03/150313-oceans-marine-life-climate-change-acidification-oxygen-fish/">increasingly widespread problem</a>. Considering that the sea floors have taken more than 1,000 years to recover from past eras of low oxygen, according to a recent University of California <a href="http://www.pnas.org/content/early/2015/03/24/1417130112.full.pdf?with-ds=yes">study</a>, this is a serious problem.</p>
<p>Ocean regions with low oxygen levels have a huge impact on aquatic organisms and can even destroy entire ecosystems. Areas of extremely low oxygen, known as <a href="https://depts.washington.edu/aog/oxygen-minimum-zones/">oxygen minimum zones</a> or “dead zones”, are estimated to constitute 10% and rising of the world’s ocean.</p>
<p>This expansion has been attributed to a warming climate, which increases water temperature, changes ocean circulation, and decreases the solubility of oxygen in sea water. At the same time <a href="http://pesticidestewardship.org/water/Pages/Runoff.aspx">fertiliser and pesticide run-off</a> from farming and other human activities leads to rising levels of nutrients such as nitrogen and phosphorous reaching the sea. </p>
<p>Together, these two processes speed up the release of chemicals from ocean sediments and promote <a href="http://www.sciencedaily.com/articles/a/algal_bloom.htm">algal blooms</a>. Subsequent algal death and decay result in increased consumption of oxygen in the water. The result is that other aquatic species such as invertebrates on the seafloor and fish suffocate for lack of oxygen.</p>
<p>Due to circulation and runoff effects, dead zones are especially severe around large cities on the western continental coasts such as the coast of Peru, and within enclosed or semi-enclosed regions like the Baltic Sea or Gulf of Mexico.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/76822/original/image-20150401-31292-uwe48r.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/76822/original/image-20150401-31292-uwe48r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/76822/original/image-20150401-31292-uwe48r.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=312&fit=crop&dpr=1 600w, https://images.theconversation.com/files/76822/original/image-20150401-31292-uwe48r.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=312&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/76822/original/image-20150401-31292-uwe48r.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=312&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/76822/original/image-20150401-31292-uwe48r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=392&fit=crop&dpr=1 754w, https://images.theconversation.com/files/76822/original/image-20150401-31292-uwe48r.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=392&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/76822/original/image-20150401-31292-uwe48r.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=392&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Oxygen levels at 300m, with extremely low oxygen oceanic ‘dead zones’ marked in red.</span>
<span class="attribution"><a class="source" href="http://www.mpi-bremen.de/en/How_the_Ocean_loses_nitrogen.html">World Ocean Atlas/Max Planck Institute for Marine Microbiology</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Looking to the past</h2>
<p>What effects will these changes have? We don’t yet know how great the effects of human-caused climate change will be, nor how much can be done to try and mitigate the effects on the environment. Even if oceanic oxygen levels rise again, will the world’s ocean ecosystems be able to recover? </p>
<p>The <a href="http://www.pnas.org/content/early/2015/03/24/1417130112.full.pdf?with-ds=yes">University of California study</a>, published in the Proceedings of the National Academy of Sciences, studies fossils of over 5,400 sea animals including seed shrimps, molluscs, and brittle stars in order to try and answer this question. By examining seafloor sediments the researchers assessed how global warming affected sealife during the transition from the last ice age to the more-recent interglacial period, between 17,000-3,000 years ago.</p>
<p>What the study found was that within only 130 years the oceans underwent devastating changes that led to complete collapse of invertebrates on the seafloor. More worryingly, the fossil records show that ecosystem recovery took at least 1,000 years.</p>
<p>So the current growth of dead zones could leave drastic and long-lasting changes to marine life biodiversity. Climate change caused by human activity has already caused significant environmental damage over a relatively short time – the vast increase in pollution, ocean acidification, overfishing and deforestation in just the last 50-100 years, for example. However long it takes us to reverse the effects of global warming, if indeed we can, it will likely take ocean ecosystems many orders of magnitude longer to recover.</p>
<h2>Headed for collapse?</h2>
<p>Though microscopic organisms residing in the ocean and on the seafloor might seem to have little relevance to us, even small changes in ocean ecosystems can have enormous effects on the entire ocean food chain, from the smallest bacteria to the largest fish. Any impact on the creatures higher up in the food chain will have a massive impact on the human communities that rely on them economically and as a food source.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/76819/original/image-20150401-31282-a5ciw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/76819/original/image-20150401-31282-a5ciw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/76819/original/image-20150401-31282-a5ciw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/76819/original/image-20150401-31282-a5ciw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/76819/original/image-20150401-31282-a5ciw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/76819/original/image-20150401-31282-a5ciw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/76819/original/image-20150401-31282-a5ciw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Algal blooms - the green sludge - are on the rise.</span>
<span class="attribution"><span class="source">Lee Bryant</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><a href="http://www.oceanscientists.org/index.php/topics/ocean-deoxygenation">Studies</a> have shown that populations of mid-water fish such as <a href="http://www.fishwatch.gov/seafood_profiles/species/whiting/species_pages/pacific_whiting.htm">Pacific hake</a> decreased by up to 60% during periods of low oxygen off the coast of Southern California. </p>
<p>Conversely, numbers of Humboldt squid, which are more tolerant of low-oxygen waters, have <a href="http://www.oceanscientists.org/index.php/topics/ocean-deoxygenation">increased significantly</a> in the same location. Even the fish that can survive in dead zones are not faring well: large numbers of female Atlantic Croaker have been found to be growing <a href="http://news.nationalgeographic.com/news/2011/05/110531-female-fish-sex-testes-gulf-dead-zone-freshwater-environment/">testes-like organs</a> instead of ovaries, a sexual deformation which causes infertility.</p>
<h2>Feedback loop</h2>
<p>Any shifts in ecosystem biodiversity can lead to a vicious feedback loop: dead zone seafloors turn into biodiversity deserts, where little but methane- and hydrogen sulphide-producing bacteria <a href="http://www.sciencedaily.com/releases/2014/03/140331153616.htm">survive</a>. Paired with changes in nutrient cycling which result in the release of <a href="http://www.mpi-bremen.de/en/Anammox_Bacteria_produce_Nitrogen_Gas_in_Oceans_Snackbar.html">nitrogen gas</a>, levels of greenhouse gases being released from the ocean to the atmosphere increase and contribute to further global warming.</p>
<p>To prevent the possibility of a 1,000-year (or longer) recovery period from a dead zone seafloor, we need to be much more aware of how the various environmental aspects are connected. An understanding of how de-oxygenation has affected the ocean in the past and how our actions are affecting the ocean in the present is critical to either preventing a recurrence or at least minimising effects of what we have already done.</p><img src="https://counter.theconversation.com/content/39668/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lee Bryant 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>The oxygen is being sucked out of the ocean, and while much of it is happening far below the surface, it will still affect us above.Lee Bryant, Prize Fellow in Water Engineering, Architecture and Civil Engineering Department, University of BathLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/379932015-02-24T23:10:51Z2015-02-24T23:10:51ZIf you speak Mandarin, your brain is different<figure><img src="https://images.theconversation.com/files/72914/original/image-20150224-25707-s1vf42.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">From left to right. Mandarin employs a different part of the brain. </span> <span class="attribution"><span class="source">Chinese man via XiXinXing/Shutterstock</span></span></figcaption></figure><p>We speak so effortlessly that most of us never think about it. But psychologists and neuroscientists are captivated by the human capacity to communicate with language. By the time a child can tie his or her shoes, enough words and rules have been mastered to allow the expression of an unlimited number of utterances. The uniqueness of this behaviour to the human species indicates its centrality to human psychology. </p>
<p>That this behaviour comes naturally and seemingly effortlessly in the first few years of life merely fascinates us further. Untangling the brain’s mechanisms for language has been a pillar of neuroscience since its inception. <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1416000112">New research</a> published in the Proceedings for the National Academy of Sciences about the different connections going on in the brains of Mandarin and English speakers, demonstrates just how flexible our ability to learn language really is.</p>
<h2>Real-time brain networking</h2>
<p>Before functional brain imaging was possible, two areas on the left side of the brain, called Broca’s area and Wernicke’s area, had already revealed their importance for language. Victims of <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=2728096">stroke or traumatic brain injury</a> to either of these crucial areas on the left side of the brain exhibited profound disabilities for producing and understanding language. Modern <a href="http://plato.stanford.edu/entries/connectionism/">theories on connectionism</a> – the idea that knowledge is distributed across different parts of the brain and not tucked into dedicated modules like Broca’s area – have compelled researchers to take a closer look.</p>
<p>For example, language requires real-time mappings between words and their meanings. This <a href="http://www.nature.com/nrn/journal/v8/n5/abs/nrn2113.html">requires that</a> the sounds heard in speech – decoded in the auditory cortex – must be integrated with knowledge about what they mean – in the frontal cortex. Modern theories in neuroscience are enamoured with this type of “network” approach. Instead of pinning miracles of cognition to singular brain areas, complex processes are now viewed as distributed across different cortical areas, relying on several parts of the brain interacting dynamically.</p>
<h2>Comparing tongues</h2>
<p>By <a href="http://www.nature.com/nature/journal/v388/n6640/abs/388381a0.html">six to ten months</a> children have already learned to be sensitive to the basic sounds, known as phonemes, that matter in their native language. Yet different languages differ profoundly in the sounds that are important for communication. </p>
<p>Mandarin Chinese is a tonal language in which the same basic sounds can refer to vastly different things based on the tone with which it is spoken. In a non-tonal language such as English, tone might convey emotional information about the speaker, but indicates nothing about the meaning of the word that is spoken.</p>
<p>Now a group of Chinese researchers, led by Jianqiao Ge
at Peking University, Beijing, has found that these differences between Mandarin Chinese and English change the way the brain’s networks work. </p>
<p>The researchers took advantage of the basic differences between Mandarin Chinese and English to investigate the differences between the language networks of native speakers of tonal and non-tonal languages. Thirty native Chinese speakers were matched on age, gender, and handedness (they were all right-handed) with a sample of native English speakers. All participants listened to intelligible and unintelligible speech and were asked to judge the gender of the speaker.</p>
<h2>The right side</h2>
<p>Both groups of speakers showed activation of the brain’s classic go-to areas for speech – including Broca’s and Wernicke’s areas – on the left side of the brain. But two important differences emerged. The first difference was the operation of the brain networks shared by English and Chinese speakers. English speakers showed stronger connectivity leading from Wernicke’s area to Broca’s area. This increased connectivity was attributed to English relying more heavily on phonological information, or sounds rather than tones. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/72911/original/image-20150224-25698-1cnownq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/72911/original/image-20150224-25698-1cnownq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/72911/original/image-20150224-25698-1cnownq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=407&fit=crop&dpr=1 600w, https://images.theconversation.com/files/72911/original/image-20150224-25698-1cnownq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=407&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/72911/original/image-20150224-25698-1cnownq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=407&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/72911/original/image-20150224-25698-1cnownq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=511&fit=crop&dpr=1 754w, https://images.theconversation.com/files/72911/original/image-20150224-25698-1cnownq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=511&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/72911/original/image-20150224-25698-1cnownq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=511&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Two areas on the left hand side of the brain associated with language.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File%3A1605_Brocas_and_Wernickes_Areas-02.jpg">OpenStax College/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Meanwhile, Chinese speakers had stronger connections leading from an area of the brain called the anterior superior temporal gyrus – which <a href="http://www.ncbi.nlm.nih.gov/pubmed/21391767">has been identified</a> as a “semantic hub” critical in supporting language – to both Broca’s and Wernicke’s area. This increased connectivity is attributed to the enhanced mapping of sound and meaning going on in people who speak tonal languages. </p>
<p>The second difference showed activation in an area of the brain’s right hemisphere, but only among the Chinese speakers. This brain area, the right superior temporal pole, <a href="https://kclpure.kcl.ac.uk/portal/en/publications/neuroanatomical-markers-of-speaking-chinese%281833ab3b-3368-4893-a4fc-954347b8410f%29/export.html">has been implicated</a> in Chinese tones before but – perhaps more importantly – has until now been considered completely separate from the classic language network in the left hemisphere. </p>
<p>The findings emphasise the importance of developing a bilateral network between the two brain hemispheres to speak and understand languages, particularly for tonal languages like Mandarin Chinese.</p>
<h2>New avenues for research</h2>
<p>We can expect more such differences to emerge as future research focuses increasingly on non-English speaking participants. Much of what we think we know about human psychology is based on <a href="http://coevolution.psych.ubc.ca/pdfs/not_Weird.pdf">“WEIRD” participants</a>: western, educated university students from industrialised, rich, and developed nations. Other cross-linguistic, cross-cultural, or cross-class differences might emerge as more research develops. </p>
<p>Provocative though the results might be, they raise questions for future research. Tone matters in English, just not to the same extent as in Chinese. For example, think of how your delivery might change the meaning of the question “Where have you been?” to convey suspicion, surprise, curiosity, or jealousy. Language might be among our most important windows to human thought, but research has barely scratched the surface of this complex and curiously unique human ability.</p><img src="https://counter.theconversation.com/content/37993/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Larry Taylor 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>Language is traditionally associated with the left side of the brain. But Mandarin speakers are using the right side.Larry Taylor, Senior lecturer, Department of Psychology, Northumbria University, NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/333752015-02-10T02:35:03Z2015-02-10T02:35:03ZDown syndrome theory on Hobbit species doesn’t hold to scrutiny<figure><img src="https://images.theconversation.com/files/63599/original/xj7yyzss-1415076243.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The skull of Liang Bua 1.</span> <span class="attribution"><span class="source">Courtesy Prof Michael Morwood</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Claims that bones found in an Indonesian cave are not the remains of a new species of extinct hominin but more likely modern humans suffering from a chromosomal disorder have been disputed by a new look at the evidence.</p>
<p>Last year Prof Maciej Henneberg, of the University of Adelaide, and his colleagues sparked intense debate among human evolution researchers when they published a pair of papers (<a href="http://www.pnas.org/content/111/33/11967">here</a> and <a href="http://www.pnas.org/content/111/33/11961">here</a>) in the Proceedings of the National Academy of Sciences.</p>
<p>Henneberg and colleagues argued that the so-called Hobbits – known by their scientific name <em><a href="http://australianmuseum.net.au/homo-floresiensis">Homo floresiensis</a></em> – were not a new species of early hominin but just small-bodied modern <a href="https://theconversation.com/hobbit-more-likely-had-down-syndrome-than-a-new-species-30067">humans with Down syndrome</a>.</p>
<p>It’s now <a href="https://theconversation.com/a-decade-on-and-the-hobbit-still-holds-secrets-33454">more than ten years</a> since a joint Indonesian-Australian team led by the late Prof <a href="https://theconversation.com/archaeologist-who-discovered-the-hobbit-dies-16321">Michael Morwood</a> announced the discovery of the famous Hobbit fossils from the site of Liang Bua on the island of Flores, Indonesia.</p>
<p>Opinions about the significance of the fossils for our understanding of human evolution are generally accepted by the majority of the scientific community, although some researchers argue that the Hobbits are pathological modern humans.</p>
<p>But the Down syndrome argument does not hold on the basis of the evidence from the two lower jaws (mandibles) from the site, which belong to individuals known as LB1 and LB6, as we argue in a reply <a href="http://www.pnas.org/content/early/2015/02/05/1418997112.extract">published this month</a>, also in the Proceedings of the National Academy of Sciences USA.</p>
<p>Here we summarise the main points we make in our reply.</p>
<h2>No support for a key claim</h2>
<p>The LB1 and LB6 mandibles are crucial to Henneberg and colleagues’ argument. Both specimens have a “negative chin,” which is where the outer surface of the bone at the front of the mandible, below the incisors, recedes.</p>
<p>The researchers who first described the Hobbit fossils argued that this trait sets the LB1 and LB6 mandibles apart from modern humans, who have a protruding chin, and aligns them with the early hominins, who have negative chins (as shown in the image below of the African <em>Homo ergaster</em> fossil OH 22 below).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/71398/original/image-20150208-28594-47io71.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/71398/original/image-20150208-28594-47io71.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/71398/original/image-20150208-28594-47io71.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/71398/original/image-20150208-28594-47io71.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/71398/original/image-20150208-28594-47io71.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/71398/original/image-20150208-28594-47io71.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/71398/original/image-20150208-28594-47io71.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/71398/original/image-20150208-28594-47io71.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&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 mandible of Olduvai Hominid 22 (OH 22) illustrates the archaic nature of the negative chin.</span>
<span class="attribution"><span class="source">Professor Colin Groves</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Henneberg and colleagues reject this claim. They contend that negative chins are often found among the indigenous people of Australia and Melanesia. Consequently, they suggest, the occurrence of negative chins on LB1 and LB6 does not stop them from being modern humans.</p>
<p>Henneberg and colleagues offer three pieces of evidence in support of their assertion that negative chins are commonplace among the indigenous people of Australia and Melanesia: two previous studies and a photograph (see figure S3 in the <a href="http://www.pnas.org/content/suppl/2014/07/31/1407385111.DCSupplemental/pnas.201407385SI.pdf">Supporting Information</a>) of a mandible from an Australian archaeological site called Roonka.</p>
<p>Unfortunately, none of these pieces of evidence withstands scrutiny. One of the studies has not been published, which means that it has not been peer-reviewed and therefore does not meet the minimum standard of scientific quality.</p>
<p>The other study has been published in a respectable peer-reviewed scientific journal but has since been <a href="http://www.plosone.org/article/metrics/info%3Adoi%2F10.1371%2Fjournal.pone.0003015">severely criticised</a>.</p>
<p>And the Roonka mandible does not have a negative chin. This can be seen clearly in the figure (below), which compares a CT scan of the LB1 mandible with a CT scan of the Roonka mandible.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/62615/original/grjp994x-1414053417.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/62615/original/grjp994x-1414053417.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/62615/original/grjp994x-1414053417.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=591&fit=crop&dpr=1 600w, https://images.theconversation.com/files/62615/original/grjp994x-1414053417.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=591&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/62615/original/grjp994x-1414053417.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=591&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/62615/original/grjp994x-1414053417.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=743&fit=crop&dpr=1 754w, https://images.theconversation.com/files/62615/original/grjp994x-1414053417.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=743&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/62615/original/grjp994x-1414053417.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=743&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 mandible of LB1 (in blue) compared to that of an indigenous person from the archaeological site of Roonka, Australia.</span>
<span class="attribution"><span class="source">CT scan of LB1 courtesy Prof Mike Morwood; CT scan of Roonka 45 generated by Assoc Prof Arthur Durband</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Thus, there is no reason to believe that Australo-Melanesians often have negative chins and therefore no reason to overturn the assessment that the negative chins in LB1 and LB6 precludes their attribution to <em>Homo sapiens</em>.</p>
<h2>More inconsistent data</h2>
<p>The chin is not the only feature of the LB1 and LB6 mandibles that does not support Henneberg and colleagues’ argument.</p>
<p>A study that was <a href="http://www.sciencedirect.com/science/article/pii/S0047248409000876">published several years</a> ago identified a number of other traits that LB1 and LB6 share with early hominins but not with modern humans.</p>
<p>One of these traits can be seen in both the photograph of the OH 22 mandible and the CT scan of the LB1 mandible. On the inside of the front of the mandible there is a bulge. Such “buttresses” are common in early hominin mandibles but are not found in modern human jaws.</p>
<p>A second trait that distinguishes the LB1 and LB6 mandibles from those of modern humans is the presence of distinct gap between the end of the tooth row and the rear section of the jaw.</p>
<p>A third trait that links LB1 and LB6 with the early hominins rather than modern humans is the form of their tooth roots.</p>
<p>Henneberg and colleagues ignored these traits, but their presence in LB1 and LB6 provides strong support for the hypothesis that the Liang Bua fossils are the remains of early hominins and not those of modern humans.</p>
<h2>Taking it on the chin</h2>
<p>The Down syndrome hypothesis is the latest in a long line of attempts to explain the features of the Liang Bua hominin fossils as pathologies.</p>
<p>It should be the last, we think.</p>
<p>The mandibular evidence disproves the idea that LB1 and LB6 are modern humans, and there are a number of other lines of evidence that do so too, as the work of Prof William Jungers, Prof Peter Brown, and several other colleagues has demonstrated.</p>
<p>It is time for the field to move on. The Hobbits are a new species of early hominins not modern humans with Down syndrome or indeed any other pathological condition.</p><img src="https://counter.theconversation.com/content/33375/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Westaway receives funding from Griffith University and the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Arthur Durband receives funding from Texas Tech University and the Australian-American Fulbright Commission.</span></em></p><p class="fine-print"><em><span>Mark Collard receives funding from the Social Sciences and Humanities Research Council of Canada, the Canada Foundation for Innovation, the British Columbia Knowledge Development Fund, and Simon Fraser University.</span></em></p>Claims that bones found in an Indonesian cave are not the remains of a new species of extinct hominin but more likely modern humans suffering from a chromosomal disorder have been disputed by a new look…Michael Westaway, Senior Research Fellow, Environmental Futures Research Institute, Griffith UniversityArthur Durband, Associate Professor of Anthropology, Texas Tech UniversityMark Collard, Canada Research Chair in Human Evolutionary Studies, and Professor of Archaeology, Simon Fraser UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/362282015-01-14T12:52:35Z2015-01-14T12:52:35ZYou are what you ‘like’, according to new Facebook personality test<p>Pretty much all of us work with computers these days. The problem with computers is that while they can complete complex calculations and recall distant details, they’re terrible at sensing how you’re feeling. And that can make them very frustrating.</p>
<p>Machines’ lack of a capacity for empathy is one thing that separates them from humans. It’s also one of the barriers to human-machine communication. For a machine to respond correctly to someone’s emotional state the machine must understand the personality of the person involved. Personality pervades our communication process, to the extent that the same smile can mean different things.</p>
<p>Sherlock Holmes, that great fictional investigator, was expert at inferring someone’s history and personality from minor scraps of evidence. It’s perhaps reassuring that Holmes’ insight and the likes of television psychologists in <a href="http://www.imdb.com/title/tt0105977/">Cracker</a> or <a href="http://www.imdb.com/title/tt1235099/">Lie To Me</a> exist only in fiction. </p>
<p>However a recent <a href="http://www.pnas.org/content/early/2015/01/07/1418680112">paper</a> by researchers from the University of Cambridge and Stanford University published in the Proceedings of the National Academy of Sciences in the US describes <a href="http://www.psychometrics.cam.ac.uk/productsservices/you-are-what-you-like">a computer program</a> capable of making accurate guesses concerning someone’s personality type. These predictions turned out to be more accurate than those of their employer, friends, and even family. This isn’t the first achievement of its kind, but the first to have compared people’s self-reported personality types against external judges, both human and artificial.</p>
<p>The raw material in this case were the Facebook profiles of 86,220 volunteers, from which the “likes” were examined to form a view of the subject’s personality, were compared to the volunteers responses to the <a href="http://pages.uoregon.edu/sanjay/bigfive.html">“big five” personality traits</a>, extroversion, openness, agreeableness, conscientiousness and neuroticism. Friends of 17,622 volunteers also judged the personality of the volunteer as a comparison. </p>
<p>With a baseline of about 60 likes the algorithms were able to put forward a reasonable guess. With 300 likes or more it tended to make more accurate guesses than most people. In many cases the machine’s ability to identify cases of likely depression or impulsivity were better than that of the people who actually knew the subjects in real life.</p>
<p>While this is a significant improvement in terms of computers comprehending the unspoken and unwritten aspects of human communication, it does raise some interesting ethical questions.</p>
<h2>Naturally speaking</h2>
<p><a href="http://www.mattersight.com/">Mattersight</a> is a company that provides behavioural analytics software. What’s this? Well, for example, when a customer phones a call centre it listens to them during the call and next time the customer phones, based on their previous tone of voice and other verbal clues, it routes the call to an operator more similar to the caller. Talking to someone like you has been shown to increase sales and reduce complaints. This isn’t just true of conversations between people, but with machines too.</p>
<p>As emotion is naturally carried in our voices, computerised voice technology is one of the areas we’ve adapted to demonstrating it. With a plotline in the television series The Big Bang Theory about <a href="http://bigbangtheory.wikia.com/wiki/Siri">dating Apple’s talking assistant Siri</a>, and the film <a href="https://www.youtube.com/watch?v=WzV6mXIOVl4">Her</a> in which a man falls in love with the artificial intelligence of his computer, people seem ready to accept that speech technology will be emotionally responsive. </p>
<figure>
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<p>Microsoft’s <a href="http://www.windowsphone.com/en-gb/how-to/wp8/cortana/meet-cortana">Cortana</a> (named after the <a href="http://halo.wikia.com/wiki/Cortana">AI from the Halo video game</a>) is an attempt to leapfrog Apple’s Siri and other competing speaking personal assistants such as <a href="http://www.myjibo.com">Jibo</a> and Amazon’s <a href="http://www.amazon.com/oc/echo">Echo</a>. By mining information about you from the phone and linked services such as social media websites it seeks to become more compatible with you. </p>
<p>A <a href="http://www.bitrebels.com/technology/siri-update-statistics-infographic/">survey</a> revealed 65% of owners use Siri regularly, so the technical difficulties of voice recognition seem to have been mastered. People with emotional attachments to their devices seem to be more forgiving of imperfections – something the new generation of voice-based hardware will require.</p>
<h2>Love me, love my robot</h2>
<p>Emotional attachment to robots is not just for films. A <a href="http://www.cc.gatech.edu/%7Ebeki/c35.pdf">study</a> of the <a href="http://www.irobot.com/For-the-Home/Vacuum-Cleaning/Roomba.aspx">Roomba</a> automatic floor vacuuming robot famous from <a href="https://www.youtube.com/watch?v=Of2HU3LGdbo">YouTube cat videos</a> shows that unlike other vacuums people become very emotionally attached to their Roombas – giving them names, creating <a href="http://www.myroombud.com/">custom clothes</a> for them, helping them do their job. </p>
<p>Providing your device with personality is a way of creating customer loyalty. While this was never the intention with the Roomba, people’s willingness to anthropomorphise their machines also means owners were willing to forgive the imperfections of early models. Adding the ability to scan Facebook and other social network profiles to build up a picture from “likes” that identifies your personality type will allow a machine to become a more personable device. </p>
<p>Alternatively it might just be that by ignoring what people say and looking at what they do, the study’s personality algorithm was able to bypass Facebook users’ usual personality curation. People tend to only share positive statements about themselves and as such it is possible to feel that everyone else’s lives are better than your own. It’s known that most users of Facebook <a href="http://warhol.wiwi.hu-berlin.de/%7Ehkrasnova/Ongoing_Research_files/WI%202013%20Final%20Submission%20Krasnova.pdf">experience very negative emotions</a> after using the site. This even reaches the state where the degree to which you think others are happier than you or how much you think life is fair <a href="http://online.liebertpub.com/doi/abs/10.1089/cyber.2011.0324">is proportional to the amount of time spent on Facebook</a>. </p>
<p>By studying what people like and their actions on Facebook it’s possible to arrive at a personality assessment based on data that has been less micro-managed, and so the real person stands out from the noise. In essence, it says that machines can establish that you really are what you “like”.</p>
<p>Given that your personality has been shown to predict things like substance use or depression, should you be worried about a digital Sherlock watching you? Well, while the machine was more accurate at predicting depression then friends and even family, everyone’s scores were pretty low (wrong on three out of four occasions) – a step up perhaps, but from a low base.</p><img src="https://counter.theconversation.com/content/36228/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nick Dalton 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>Pretty much all of us work with computers these days. The problem with computers is that while they can complete complex calculations and recall distant details, they’re terrible at sensing how you’re…Nick Dalton, Lecturer, Computing and Communications, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/360452015-01-12T21:39:18Z2015-01-12T21:39:18ZKeeping actively bilingual makes our brains more efficient at relaying information<figure><img src="https://images.theconversation.com/files/68676/original/image-20150112-23798-16ufj3h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What speaking two languages does to the brain's white matter. </span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-56197051/stock-photo-brain-illustration.html?src=pp-same_artist-72018124-6W8NU0OUx9D9rQPN3dQ9mg-4">Brain illustration via Jezper/Shutterstock</a></span></figcaption></figure><p>There is increasing evidence that bilingualism can affect how the brain works. Older, lifelong bilinguals <a href="http://kwistuup.net/_/mss/BIALYSTOK_etal_2008.pdf">have demonstrated</a> better cognitive skills in tasks that require increased cognitive control. These cognitive effects are most pronounced in bilingual people who speak two languages in their everyday life for many years, compared to those who speak a second language but don’t use it often. Our <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1414183112">new research</a> has now highlighted the structural improvements on the brain observed in bilingual people who immerse themselves in two languages. </p>
<p>Bilingualism affects the structure of the brain including both major types of brain tissue – the grey matter and the white matter. The neurons in our brain have two distinct anatomical features: their cell bodies, where all the processing of information, thinking and planning happens, and their axons, which are the main avenues that connect brain areas and transfer information between them. The cell bodies are organised around the surface of the brain – the grey matter – and all the axons converge and interconnect underneath this into the white matter. </p>
<p>We call it white matter because the axons are wrapped in a fatty layer, the myelin, which ensures better neuronal communication – the way information is transferred around the brain. The myelin functions as an “insulation” that prevents information “leaking” from the axon during transfer. </p>
<h2>Language-learning restructures the brain</h2>
<p>Bilingualism <a href="http://www.nature.com/nature/journal/v431/n7010/full/431757a.html">has been shown to</a> increase the volume of grey matter in several brain areas that are usually connected to <a href="http://www.ncbi.nlm.nih.gov/pubmed/21106192">language learning</a> and <a href="http://link.springer.com/article/10.1007%2Fs12311-013-0515-6#page-1">processing</a>. These effects suggest that the brain is capable of restructuring itself as a response to learning an additional language, but also as a response to the equally important task of juggling between two languages – using one language while suppressing the other at any given time. </p>
<p>This latter task poses particular cognitive demands for bilinguals, which do not apply to monolinguals. In order to handle the additional information successfully, the avenues of white matter in bilinguals’ brains that transfer information and select between two different languages must become more efficient. </p>
<h2>Bilingualism makes brains more efficient</h2>
<p>One way for the white matter to become more efficient is to increase its “insulation”, the myelin, making the transfer of information faster and with fewer losses. It has been shown that <a href="http://www.ncbi.nlm.nih.gov/pubmed/22090506">older lifelong bilinguals</a>, <a href="http://www.ncbi.nlm.nih.gov/pubmed/22197702">young early bilinguals</a> and <a href="http://www.ncbi.nlm.nih.gov/pubmed/21106192">adult early bilinguals</a> demonstrate increased integrity, or thickness of the myelin – known as “myelination” – compared to monolinguals. Some researchers have <a href="http://www.ncbi.nlm.nih.gov/pubmed/22090506">even suggested</a> that the experience of lifelong bilingualism preserves the myelination (or the integrity) of the white matter from natural deterioration in older age.</p>
<p>Based on these suggestions, our research wanted to investigate whether similar effects to white matter would be observed in late bilinguals, when compared to monolinguals of the same age and education. We defined “late bilinguals” as people who learnt their second language at around the age of 10. The existing research on late bilinguals has demonstrated that they also <a href="http://www.ncbi.nlm.nih.gov/pubmed/22571459">show changes in white matter structure</a> during second language training, but these disappear if the <a href="http://www.ncbi.nlm.nih.gov/pubmed/23966688">second language is not actively used</a>. </p>
<h2>What happens to white matter</h2>
<p>We tested 20 young bilinguals with an average age of 30-years-old who had lived in the UK for at least 13 months and were highly-proficient and active users of English as a second language, but were not undergoing any language training at the time. In other words, our participants were young, highly-proficient “immersed” bilinguals. These were compared to 25 monolingual adults of the same age and educational level.</p>
<p>We scanned and compared the two groups with an MRI technique called diffusion tensor imaging, which uses the movement of water molecules in the brain as an indicator for white matter integrity. A freer movement of the water molecules indicates less integrity. </p>
<p><a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8770967&fileId=S136672891200017X">Previous research</a> suggested that late-immersed bilinguals<a href="http://link.springer.com/article/10.1007%2Fs12311-013-0515-6#page-1"> show changes</a> in grey matter structure, as well as processing of their second language <a href="http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8770967&fileId=S136672891200017X">similar to that of native speakers</a>. So we predicted the impact of language immersion would be similar on the white matter for our bilinguals. </p>
<p>This is precisely what we found: compared to monolingual adults of a similar age, our bilinguals demonstrated greater white matter integrity in a number of regions of the brain related to language processing. This closely corresponded to the effects on the brain for early and older bilinguals.</p>
<h2>Immersion is key</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/68677/original/image-20150112-23786-8gczpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/68677/original/image-20150112-23786-8gczpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/68677/original/image-20150112-23786-8gczpi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/68677/original/image-20150112-23786-8gczpi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/68677/original/image-20150112-23786-8gczpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/68677/original/image-20150112-23786-8gczpi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/68677/original/image-20150112-23786-8gczpi.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">Keeping the language up is key.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-148199825/stock-photo-tongue-with-the-flag-of-spain-translating-illustration.html?src=Sv-uXu69V3OL-mXkKCtKbg-1-19">Spanish tongue via johnyf33/Shutterstock</a></span>
</figcaption>
</figure>
<p>Our findings further support the idea that bilingualism “reshapes” the brain, but also suggest that bilingual immersion is a crucial factor in the process. In other words, it is possible that the better preservation of brain structure that has been reported in older bilinguals is simply an effect of continuously using the two languages, rather than an effect of early language acquisition or lifelong bilingualism. </p>
<p>As a result, any effects of bilingualism on the structure of white matter in the brain seem to be independent of the critical periods when people are learning a language. Although it is possible that there might be a link between the increased connectivity between brain areas and the cognitive benefits reported in bilinguals, our study did not test for that and it’s well worth future investigation.</p><img src="https://counter.theconversation.com/content/36045/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christos Pliatsikas 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>There is increasing evidence that bilingualism can affect how the brain works. Older, lifelong bilinguals have demonstrated better cognitive skills in tasks that require increased cognitive control. These…Christos Pliatsikas, Lecturer in Cognitive Psychology, University of KentLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/341052014-11-12T06:25:42Z2014-11-12T06:25:42ZLibyan bands of brothers show how deeply humans bond in adversity<figure><img src="https://images.theconversation.com/files/64299/original/gj4jfhvb-1415724887.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">I've got all my brothers with me.</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/magharebia/6263967082">Magharebia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>It’s often said that blood is thicker than water – that family ties trump all others. But research with groups of men fighting in <a href="http://www.bbc.co.uk/news/world-africa-13755445">Libya</a> has suggested that the bonds they formed in times of great adversity were as strong as those they had with their own kin. </p>
<p>During the 2011 conflict in Libya, we surveyed the civilians who had taken up arms to topple the Gaddafi-led regime and found extremely strong relationships: these men had bonded to one another as strongly as if they were brothers. </p>
<p>Those on the front line had the strongest bonds of all. Their ties were so profound that, in many cases, they were willing to die for one another. Such behaviour, where individuals show a willingness to offer the ultimate self-sacrifice and lay down their lives for people with whom they share no genes, has puzzled evolutionary scientists since the days of Darwin. </p>
<p><a href="http://www.pnas.org/content/early/2014/11/05/1416284111.full.pdf+html">Our study</a>, published in the early online version of the Proceedings of the National Academy of Sciences, is one of several pieces of research we have been conducting for the project: “Ritual, Community, and Conflict”. Anthropologists, psychologists, historians, archaeologists and evolutionary theorists are working together in this project to try to understand the forces that bind and drive human groups.</p>
<h2>In it together</h2>
<p>In July 2011, four months into the <a href="https://theconversation.com/uk/topics/libya">Libyan revolution</a>, a member of our team in Oxford, Brian McQuinn, joined a humanitarian relief convoy travelling to <a href="http://www.middleeasteye.net/news/libya-brink-1455411139">Misrata</a>, in the north-west of Libya.</p>
<p>While in Libya, he studied how the rebels began as groups of three to five fighters that later developed into the larger revolutionary groups. The members of each group prayed, slept and fought side by side.</p>
<p>I joined Brian in Libya as the conflict was ending. Together, we persuaded the revolutionary leadership in Misrata to allow us to survey 179 civilians from four different battalions registered with the <a href="http://www.aljazeera.com/category/organisation/misrata-military-council">Misrata Military Council</a>.</p>
<p>Our survey included both revolutionaries who served on the front line with weapons and non-fighters, such as workers who serviced vehicles or drove ambulances. </p>
<p>When we asked the revolutionaries to choose which group they were most bonded with, family or battalion, front-line fighters were more likely than non-fighters to choose battalion. Our findings suggest that the strongest bonds evolve through sharing the experience of war, such as the deprivation and negative stress of combat. Although most fighters were not related, they characteristically expressed feelings of brotherhood for one another.</p>
<p>We measured levels of <a href="http://www.europhd.eu/html/_onda02/07/PDF/20th_lab_materials/jane/swan_et_al_2009.pdf">identity fusion</a> – a visceral sense of oneness with the group that has been used in many previous <a href="http://www.ncbi.nlm.nih.gov/pubmed/22642548">studies</a>. </p>
<p>Each individual was asked to represent their relationship to the group by choosing from a series of pictures that represented different degrees of overlap between themselves and three groups: their families, their battalions and other battalions. Those who chose the picture in which the “self” overlapped completely with the group were said to be “fused” with the group in question. </p>
<p>We found that 99% of front-line fighters had strong bonds or were “fused” with their own families – but perhaps more strikingly, 97% also indicated fusion with their own battalions, and 96% with fighters in other battalions.</p>
<p>When they were asked which of the groups they were most connected with, nearly half (45%) of front-line fighters chose their own battalion rather than their family. By contrast, only 28% of non-fighters chose battalion over family. Interestingly, hardly anyone surveyed (only 1%) were fused with ordinary Libyans who supported the revolution but did not join the battalions.</p>
<h2>Strength in numbers</h2>
<p>One interpretation of this study is that sharing life-shaping, intense experiences, such as bearing the brunt of enemy fire, is what bonded Libya’s revolutionaries so strongly; an alternative explanation might be that those who were predisposed to bond with the battalion at the outset are most likely to end up on the front line with each other.</p>
<p>The fact that fighters experienced such low levels of fusion with ordinary Libyans was quite surprising. In our discussions with fighters, they suggested that non-combatants were incapable of understanding what the fighters had experienced during the revolution. In the minds of the revolutionary fighters, this distinction may have sowed the seeds of distrust between fighters and non-combatants after the war.</p>
<p>There are already a number of <a href="http://amj.aom.org/content/41/4/387.short">studies</a> that look at how <a href="http://afs.sagepub.com/content/33/2/286.short">cohesion in the military</a> affects <a href="http://www.tandfonline.com/doi/abs/10.1207/s15324834basp0902_6">group performance</a>, but very little research has looked at how intense bonds like these are formed – how bonding with the group can lead individuals to place themselves in harm’s way and sacrifice their lives for other group members.</p><img src="https://counter.theconversation.com/content/34105/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Harvey Whitehouse receives funding from:
Economic and Social Research Council
John Templeton Foundation
John Fell Fund
</span></em></p>It’s often said that blood is thicker than water – that family ties trump all others. But research with groups of men fighting in Libya has suggested that the bonds they formed in times of great adversity…Harvey Whitehouse, Chair professor, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/340342014-11-11T05:53:28Z2014-11-11T05:53:28ZPlaying video games is good for your brain – here’s how<figure><img src="https://images.theconversation.com/files/64153/original/fwfpr2fb-1415639547.png?ixlib=rb-1.1.0&rect=0%2C198%2C800%2C698&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Your brain, on games.</span> <span class="attribution"><a class="source" href="http://www.onlineuniversities.com/neurology-of-gaming">OnlineUniversities.com</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Whether playing video games has negative effects is something that has been debated for 30 years, in much the same way that rock and roll, television, and even the novel faced much the same criticisms in their time.</p>
<p>Purported negative effects such as addiction, increased aggression, and various health consequences such as obesity and repetitive strain injuries tend to get far more media coverage than the positives. I know from my own research examining both sides that my papers on video game addiction receive far more publicity than my research into the social benefits of, for example, <a href="http://online.liebertpub.com/doi/abs/10.1089/cpb.2007.9988">playing online role-playing games</a>. </p>
<p>However there is now a wealth of research which shows that video games can be put to <a href="http://www.apa.org/news/press/releases/2013/11/video-games.aspx">educational and therapeutic uses</a>, as well as many studies which reveal how playing video games can improve reaction times and hand-eye co-ordination. For example, research has shown that spatial visualisation ability, such as mentally rotating and manipulating two- and three-dimensional objects, <a href="http://www.cdmc.ucla.edu/PG_Media_biblio_files/kaveri_greenfield_1994.pdf">improves with video game playing</a>. </p>
<p>To add to this long line of studies demonstrating the more positive effects of video games is a <a href="http://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1417056111/">study</a> in the Proceedings of the National Academy of Sciences by <a href="http://www.princeton.edu/neuroscience/people/display_person.xml?netid=vbrao%20">Vikranth Bejjanki</a> and colleagues. Their newly published paper demonstrates that the playing of action video games – the sort of fast-paced, 3D shoot-em-up beloved of doomsayers in the media – confirms what other studies have revealed, that players show improved performance in perception, attention, and cognition. </p>
<p>In a series of experiments on small numbers of gamers (10 to 14 people in each study), the researchers reported that gamers with previous experience of playing such action video games were better at perceptual tasks such as pattern discrimination than gamers with less experience. </p>
<p>In another experiment, they trained gamers that had little previous experience of playing action games, giving them 50 hours practice. It was showed that these gamers performed much better on perceptual tasks than they had prior to their training. The paper concludes:</p>
<blockquote>
<p>The enhanced learning of the regularity and structure of environments may act as a core mechanism by which action video game play influences performance in perception, attention, and cognition. </p>
</blockquote>
<p>In <a href="https://nottinghamtrent.academia.edu/MarkGriffiths/Papers">my own papers</a>, I have pointed out many features and qualities that make video games potentially useful. For instance, in an educational context, video games can be fun and stimulating, which means it’s easier to maintain a pupil’s undivided attention for longer. Because of the excitement, video games may also be a more appealing way of learning than traditional methods for some.</p>
<p>Video games have an appeal that crosses many demographic boundaries, such as age, gender, ethnicity, or educational attainment. They can be used to help set goals and rehearse working towards them, provide feedback, reinforcement, self-esteem, and maintain a record of behavioural change. </p>
<p>Their interactivity can stimulate learning, allowing individuals to experience novelty, curiosity and challenge that stimulates learning. There is the opportunity to develop transferable skills, or practice challenging or extraordinary activities, such as flight simulators, or simulated operations.</p>
<p>Because video games can be so engaging, they can also be used therapeutically. For instance, they can be used as a <a href="http://www.igi-global.com/chapter/videogames-therapy-review-medical-psychological/78017">form of physiotherapy</a> as well as in more innovative contexts. A number of studies have shown that when children play video games following chemotherapy <a href="http://www.bmj.com/content/331/7509/122">they need fewer painkillers</a> than others.</p>
<p>Video games have great educational potential in addition to their entertainment value. Games specifically designed to address a specific problem or teach a specific skill have been very successful, precisely because they are motivating, engaging, interactive, and provide rewards and reinforcement to improve. </p>
<p>But the transferability of skills outside the game-playing context is an important factor. What’s also clear from the scientific literature is that the negative consequences of playing almost always involve people that are excessive video game players. There is little evidence of serious acute adverse effects on health from moderate play.</p><img src="https://counter.theconversation.com/content/34034/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr. Mark Griffiths has received research funding from a wide range of organizations including the Economic and Social Research Council, the British Academy and the Responsibility in Gambling Trust. He has also carried out consultancy for numerous gaming companies in the area of social responsibility and responsible gaming.</span></em></p>Whether playing video games has negative effects is something that has been debated for 30 years, in much the same way that rock and roll, television, and even the novel faced much the same criticisms…Mark Griffiths, Director of the International Gaming Research Unit and Professor of Gambling Studies, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/337062014-11-03T12:18:40Z2014-11-03T12:18:40ZMaps made from mobile phone records could help plan for the next tsunami or Ebola outbreak<figure><img src="https://images.theconversation.com/files/63444/original/y8r2c6qj-1414948775.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mobile phone networks join the dots about where we live and travel.</span> <span class="attribution"><span class="source">Ovchinnkov Vladimir</span></span></figcaption></figure><p>There are now more mobile phones in use than there are people in the world to use them – some <a href="http://www.ibtimes.co.uk/there-are-more-gadgets-there-are-people-world-1468947">7.2 billion phones</a>. Mobile phones are becoming integral parts of our lives, penetrating into areas of the developing world that lack much of the fixed infrastructure taken for granted elsewhere. This makes them an excellent potential source of information about population movements.</p>
<p>For example, in the event of a natural disaster, disease outbreak, terrorist attack or conflict, knowing where people are and how many may be affected is vital for planning a response. But these population distribution details are largely drawn from a census – typically undertaken only every ten years (<a href="http://www.ons.gov.uk/ons/guide-method/census/2011/index.html">the most recent in the UK was in 2011</a>), which means that without other sources of information the details quickly become inaccurate or incomplete. </p>
<p>In many poorer countries population census data can be very out of date: the Democratic Republic of Congo, Madagascar and Pakistan have not undertaken a census since 1984, 1993 and 1998 respectively. And in any case, a census only records residential populations in a single snapshot, without providing any detail of the daily, weekly and seasonal dynamics of population movements within countries. This means it’s difficult to accurately assess the number of people who may be affected by, for example, climate change, or conflict, or for ascertaining in which direction a disease like Ebola is likely to spread.</p>
<h2>Filling in the gaps</h2>
<p>This is where mobile phones can provide invaluable data, using the call connection records that are updated by the second. Phone subscriptions have rocketed in the last few years, with the highest rates of adoption in the world’s lowest-income nations. Every time an individual makes or receives a call or text, it is routed through the nearest receiving cell network tower. This information – the anonymous ID of the user, the time and the location of the tower the call was routed through – is recorded for billing purposes by phone network operators.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/63426/original/ddjxhtr9-1414864164.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/63426/original/ddjxhtr9-1414864164.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/63426/original/ddjxhtr9-1414864164.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=614&fit=crop&dpr=1 600w, https://images.theconversation.com/files/63426/original/ddjxhtr9-1414864164.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=614&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/63426/original/ddjxhtr9-1414864164.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=614&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/63426/original/ddjxhtr9-1414864164.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=772&fit=crop&dpr=1 754w, https://images.theconversation.com/files/63426/original/ddjxhtr9-1414864164.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=772&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/63426/original/ddjxhtr9-1414864164.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=772&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">France moves between the city and the beach.</span>
<span class="attribution"><span class="source">Andy Tatem</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>So with millions of phone users per nation, this provides a surprisingly accurate picture of human activity. Our <a href="http://www.pnas.org/content/early/2014/10/23/1408439111.abstract">study</a> published in the Proceedings of the US National Academy of Sciences draws upon just a few months of this type of anonymised data from France and Portugal. We measured the density of phone calls per cell tower and, adjusting for biases in phone usage, have been able to produce population density maps of equivalent accuracy to those produced from a census. </p>
<p>This opens up some interesting possibilities. By using just this small segment of anonymised data that is already stored by mobile network operators, it is possible to rapidly produce detailed and up-to-date population distribution maps, sidestepping the need for the cumbersome once-a-decade census in providing such data.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/qsUDH5dUnvY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>As these phone call records are continually collected, this also provides unprecedented insight into the nature of human population dynamics. Distribution maps can be easily drawn up for any period required – for example day vs night, weekday vs weekend, workday vs holiday difference. At little cost, this can help answer the type of questions that have previously been logistically challenging: how many people were likely to have been affected when a tsunami hit at 2.07pm? How have people reacted in the days following a devastating earthquake? How have mobility patterns changed in light of movement restrictions implemented for an Ebola outbreak?</p>
<p>Inevitably there will be questions about privacy and commercial interests when dealing with mobile phone records. The data contain details of the phone network operators’ system design, their customers, and of course the location of individual phone users at specific times. However, for the purposes of responding to natural disasters, conflicts or other public health emergencies, operators need not provide access to the full details. It’s sufficient to measure call density per tower with aggregated and anonymised data and still produce accurate maps.</p>
<p>In fact it’s relatively straightforward for phone network operators to produce these themselves without having to release information to third parties and run into possible privacy issues. This could become a routine step, in collaboration with governments, which would provide planners with far better understanding of population dynamics than we’ve had hitherto, and so a much better response in the face of any crisis.</p><img src="https://counter.theconversation.com/content/33706/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew J Tatem 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>There are now more mobile phones in use than there are people in the world to use them – some 7.2 billion phones. Mobile phones are becoming integral parts of our lives, penetrating into areas of the developing…Andrew J Tatem, Reader, Geography and Environment, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/325352014-10-06T20:59:38Z2014-10-06T20:59:38ZHow genes can influence children’s exam results<figure><img src="https://images.theconversation.com/files/60893/original/gdf63fft-1412588535.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What role do genes have to play? </span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-124057036/stock-photo-students-sitting-a-test-in-an-exam-hall-in-college.html?src=OsP4UyDjDaXk2r46Lb628w-1-25">Student test by wavebreakmedia/Shutterstock</a></span></figcaption></figure><p>The idea that children can inherit the ability to get good results at school can spark heated debate. But, put simply, all this means is that children differ in how easy and enjoyable they find learning and that these differences are to a large extent explained by differences in their genes, rather than differences between schools or teachers. </p>
<p>We know from previous research that educational achievement in <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1540-5834.2007.00439.x/abstract;jsessionid=2308C55109442D150D9FE8873B72AC13.f04t03">primary</a>, <a href="http://www.tweelingenregister.org/nederlands/verslaggeving/NTR_publicaties/Bartels_TR_2002.pdf">middle school</a> years and at the <a href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0080341">end of compulsory education</a> is highly heritable. Heritability is a population statistic – it doesn’t tell us anything about a single individual. It describes the extent to which differences between children can be put down to DNA differences, on average, in a particular population at a particular time.</p>
<h2>Twins’ exam results</h2>
<p>Our new <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1408777111">study</a>, published in the journal Proceedings of the National Academy of Sciences, focused on the UK-wide standardised exam results at age 16, the General Certificate of Secondary Education (GCSE). We obtained exam grades from over 13,000 identical and non-identical twins from the <a href="http://www.teds.ac.uk/">Twins Early Development Study</a> who were also assessed on nine broad psychological domains, including intelligence, educational self-belief, personality, behaviour problems, and well-being.</p>
<p>Identical twins share 100% of their genes, whereas non-identical twins, just like any siblings, share on average only half of the genes that vary between people. If overall, identical twins are more alike than non-identical twins on a particular trait, then this implies there is a genetic influence. </p>
<p>Our study showed that the mean results in the GCSE core subjects of English, mathematics and science is more heritable (62%) than the nine other psychological domains (35–58%) we looked at. </p>
<p>This means that differences in how well children perform at exams are to a large extent explained by the difference in their DNA. Importantly, it does not mean that genetics explain 62% of a single child’s school achievement. </p>
<h2>Not just intelligence</h2>
<p>When we analysed different traits, we found that educational achievement is <a href="https://theconversation.com/twins-show-success-at-school-is-not-just-down-to-genes-22373">correlated with many characteristics of children</a>, not just intelligence. Our results indicate that these correlations are largely mediated by genetic factors. To the extent that children’s traits predict educational achievement, they do so largely for genetic reasons. </p>
<p>Although intelligence accounts for more of the heritability of GCSE results than any other single domain, the joint contribution of children’s self-belief, behaviour problems, personality, well-being, and their perceptions of school environment, collectively account for about as much GCSE heritability as intelligence. Together with intelligence, these domains account for 75% of the heritability of GCSE performance. </p>
<h2>Indicator of equality</h2>
<p>The children in this study were all taught the national curriculum, so to some extent received a similar education. As children’s learning experiences become more similar, they begin to explain the similarities between them rather than the differences between them. As a result of these diminished environmental differences, the relative genetic influences increase. So in a way, high heritability is an indicator of equality. </p>
<p>For example, despite high heritability, with sufficient educational effort, nearly all children could reach minimal levels of literacy and numeracy. This is an explicit goal of education in Finland. Success in achieving that goal would reduce differences in children’s educational achievement, which could change heritability. Hypothetically, if all environmental effects on individual differences (such as educational inequality) were to be minimalised, then the heritability estimate for educational achievement would be 100%. </p>
<h2>Personalised learning</h2>
<p>So what to make of this? Genes are important, not just in educational achievement or intelligence, but in a whole raft of other traits which contribute to how easy and enjoyable children find learning. Education is more than what happens passively to a child. Children are active participants in selecting, modifying, and creating experiences that are matched to their genetic predispositions. In genetics, this is <a href="http://eu.wiley.com/WileyCDA/WileyTitle/productCd-1118482786,subjectCd-ED05.html">known as “gene-environment correlation”</a>. </p>
<p>At the practical level, our findings add support for the trend in education toward personalised learning rather than a one-size fits all model. None of this means that schools, parents or teachers aren’t important. Of course they are – and each has an important role in helping children achieve the best of their potential.</p>
<hr>
<p><em>Next read: <a href="https://theconversation.com/better-at-reading-than-maths-dont-blame-it-all-on-your-genes-28947">Better at reading than maths? Don’t blame it all on your genes </a></em></p><img src="https://counter.theconversation.com/content/32535/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eva Krapohl receives funding from the Medical Research Council Studentship.</span></em></p><p class="fine-print"><em><span>Kaili Rimfeld receives funding from the Medical Research Council Studentship. </span></em></p>The idea that children can inherit the ability to get good results at school can spark heated debate. But, put simply, all this means is that children differ in how easy and enjoyable they find learning…Eva Krapohl, Phd Student, Institute of Psychiatry, Psychology & Neuroscience, King's College LondonKaili Rimfeld, PhD Student, Institute of Psychiatry, Psychology & Neuroscience, King's College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/313972014-09-08T20:29:29Z2014-09-08T20:29:29ZIntelligence inheritance – three genes that add to your IQ score<figure><img src="https://images.theconversation.com/files/58403/original/zg38b6zs-1410142955.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">There's no one universal 'intelligence gene' but many thousands each contributing a small increment – and here are three.</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/andrew_loves_norcal/14067870750">Andrew Huff/Flickr (cropped)</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Intelligence, cognitive ability or cognitive performance is usually measured by a battery of tests that aim to quantify skills such as memory and analytical ability. There is loads of variation between people in how they perform on such tests, and these differences can be due to genetic and environment factors, and their interplay. </p>
<p>In <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1404623111">research published</a> in the Proceedings of the National Academy of Science (PNAS) today, we show three genetic variants in humans that can account for a couple of IQ points – but before you get excited, these are only three variants out of likely thousands.</p>
<h2>The genetics of cognitive performance</h2>
<p>While a measure of “intelligence” can be controversial, cognitive performance scores are widely used because of their predictive ability. Educational attainment, income, job performance and health are all correlated with cognitive performance.</p>
<p>By comparing the cognitive performance between family members, including comparisons between identical and non-identical twins, scientists are able to quantify the contribution of genetic and environmental causes of individual differences. </p>
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<a href="https://images.theconversation.com/files/58397/original/xxzzr628-1410141811.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/58397/original/xxzzr628-1410141811.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/58397/original/xxzzr628-1410141811.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=301&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58397/original/xxzzr628-1410141811.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=301&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58397/original/xxzzr628-1410141811.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=301&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58397/original/xxzzr628-1410141811.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=378&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58397/original/xxzzr628-1410141811.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=378&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58397/original/xxzzr628-1410141811.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=378&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.flickr.com/photos/miss_pupik/2716324697">shira gal/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>Decades of research have shown that genetic factors account for <a href="http://www.nature.com/ejhg/journal/v14/n6/full/5201588a.html">about half</a> of the causes of individual difference in cognitive performance, and recent studies using unrelated people have confirmed that a <a href="http://www.nature.com/mp/journal/v16/n10/abs/mp201185a.html">substantial proportion</a> of individual difference is due to genetic factors. </p>
<p>So, we know now that cognitive performance is heritable, but where are the genes? Despite considerable attempts to find genes for cognitive performance, no specific genes had been found and replicated. </p>
<p>One reason for this puzzle is that there are a lot of genes involved – thousands, even – and their individual gene effect sizes are tiny. Past studies couldn’t find them because sample sizes were not large enough to detect genes with statistical significance. </p>
<p>So how did we overcome this problem? </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/58396/original/9mqmrbft-1410141682.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/58396/original/9mqmrbft-1410141682.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/58396/original/9mqmrbft-1410141682.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=708&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58396/original/9mqmrbft-1410141682.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=708&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58396/original/9mqmrbft-1410141682.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=708&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58396/original/9mqmrbft-1410141682.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=890&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58396/original/9mqmrbft-1410141682.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=890&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58396/original/9mqmrbft-1410141682.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=890&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="http://www.flickr.com/photos/the-lobster/4014103824">daves cupboard/Flickr</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>Last year, a huge international collaborative study of <a href="http://www.sciencemag.org/content/340/6139/1467.abstract">more than 126,000 people</a> correlated millions of genetic variants with educational attainment and discovered three genetic variants associated with it. </p>
<p>Education attainment is correlated with cognitive performance, so given these two observations, we tested the genetic variants for education attainment with their associations with cognitive performance, which we report in PNAS today. </p>
<p>We tested 69 genetic variants from the educational attainment study (of almost 107,000 people) in independent samples of 24,000 people who had a cognitive performance score. This two-stage strategy is called a “proxy-phenotype method” since educational attainment is a proxy phenotype (an observable characteristic or trait) for cognitive performance. </p>
<p>The essence of this design was to piggy-back on a much larger study from a correlated trait (educational attainment) to pre-select a small number of genetic variants. These were then tested for association with cognitive performance – a bit like leveraging a large study on the genetics of weight to find genes for diabetes.</p>
<h2>Three genetic variants (out of thousands)</h2>
<p>Previously, using a genome-wide study in a sample of <a href="http://www.nature.com/mp/journal/v19/n2/full/mp2012184a.html">18,000 individuals</a>, we could not identify a single genetic variant associated with cognitive performance. Using the new proxy strategy, though, we identified three genetic variants associated with cognitive performance. As expected from the calculation, the effects of these variants on cognitive performance are tiny. </p>
<p>A copy of each variant accounts for only 0.3 points on a standard IQ test (with a mean of 100 and standard deviation of 15). A person who inherits all six copies (note: one genetic variant has two copies) of increasing variants differs by 1.8 points compared to individual who inherits none. That’s a small difference.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/58395/original/qgqn65t2-1410141588.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/58395/original/qgqn65t2-1410141588.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/58395/original/qgqn65t2-1410141588.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/58395/original/qgqn65t2-1410141588.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/58395/original/qgqn65t2-1410141588.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/58395/original/qgqn65t2-1410141588.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/58395/original/qgqn65t2-1410141588.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/58395/original/qgqn65t2-1410141588.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"></a>
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<span class="attribution"><a class="source" href="http://www.flickr.com/photos/sheeshoo/7177636487">sheeshoo/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
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</figure>
<p>Another interesting finding from our study is related to the potential relevance to our health. A combination of genetic effect calculated from 60 education attainment-associated variants is correlated with memory and absence of dementia in an independent sample of almost 9,000 individuals. </p>
<p>While it is premature to suggest the biological function of the genes identified, our additional analysis suggests that the genes are related to synaptic plasticity – the main mechanism in the brain for learning and memory.</p>
<h2>The take-away message</h2>
<p>This study of normal variation in cognitive performance confirms that there is no gene with a large effect on this trait. There is no “gene for intelligence” – instead, cognitive performance is likely to be influenced by thousands of genes, each having a small effect.</p>
<p>While the individual effect of the genetic variants are extremely small, their identification may lead to knowledge of the biological pathways involved in cognitive performance and cognitive ageing. This insight may eventually lead us into a better understanding of the mechanism involves in memory loss and dementia.</p>
<p>Finally, because individual gene effects are small, an implication of the study is that even larger studies, for example on millions of people, will lead to the discovery of many more gene variants.</p><img src="https://counter.theconversation.com/content/31397/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Beben Benyamin receives funding from the National Health and Medical Research Council (NHMRC) and the Motor Neurone Disease Research Institute of Australia (MNDRIA).</span></em></p><p class="fine-print"><em><span>Peter Visscher receives funding from the National Health and Medical Research Council, the Australian Research Council and the National Institutes of Health (USA). </span></em></p>Intelligence, cognitive ability or cognitive performance is usually measured by a battery of tests that aim to quantify skills such as memory and analytical ability. There is loads of variation between…Beben Benyamin, Research Fellow in Statistical Genetics, The University of QueenslandPeter Visscher, Professor of Quantitative Genetics, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/294602014-08-05T15:07:10Z2014-08-05T15:07:10ZNew device diagnoses sick people using a mobile phone and the cloud<figure><img src="https://images.theconversation.com/files/54816/original/qyczcqhq-1406212449.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Malaria testing could soon be done in the cloud.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/usarmyafrica/4553746920/in/photolist-7Wp9iW-7Wp9vE-7WkVn6-7djL6s-7WkSe2-7WkNfg-7WkRfD-8gTRX6-8gX8kJ-7Wp7WQ-9VJBHm-7WkQ9r-8GSqtK-7Wp9J1-8GSosi-7dgMwp-auM9GY-9NXy1b-8GVAdL-7Wp5uE-7WpaSj-bLePu2-8GVzMY-7Wp64W-avi2t9-hm6axT-8GVzYj-8GVwoA-8GVwL9-d43pe-7WkPV8-8GSojZ-8GSqfx-8GVzcq-9AKZBR-8GVyN3-7WkVWr-7Wp8rh-hm66WK-7WpacE-hfmE2U-7WkT12-9i31j-7Wp7Am-7WkPKR-7WkU7K-7Wpax5-7Wp5R3-5t3rFY-8GVAyy">US Army Africa</a></span></figcaption></figure><p>Remote diagnostics is an emerging field that allows healthcare workers to perform tests on patient samples in the field and to get results interpreted by medical experts remotely. This is a groundbreaking approach to providing affordable healthcare to patients in some of the world’s poorest countries.</p>
<p>Providing healthcare in this way, though, often means using expensive equipment, supplying extensive training and getting access to relatively developed telecommunications infrastructure. In a <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1405679111">paper</a> published in the Proceedings of the National Academy of Sciences today, we present a device that has the potential to overcome these challenges.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/55633/original/xb8h9hmp-1407123811.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/55633/original/xb8h9hmp-1407123811.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/55633/original/xb8h9hmp-1407123811.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=550&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55633/original/xb8h9hmp-1407123811.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=550&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55633/original/xb8h9hmp-1407123811.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=550&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55633/original/xb8h9hmp-1407123811.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=691&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55633/original/xb8h9hmp-1407123811.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=691&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55633/original/xb8h9hmp-1407123811.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=691&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 uMED.</span>
<span class="attribution"><span class="source">Alex Nemiroski</span></span>
</figcaption>
</figure>
<p>Costing only US$25, the universal Mobile Electrochemical Detector, or uMED, can perform chemical and biochemical tests on a variety of commercially available test strips and electrodes and send the results over an audio cable connected to the headphone jack of any cell phone – even if it isn’t a smartphone. After placing a phone call, the user can upload the data over the voice channel of any mobile network (2G, 3G, or 4G) that is present on site. There is no need for an internet connection.</p>
<p>An automated cloud database or a medical expert can then return relevant information about test results to the device by text message. The cloud database might be run by a private hospital or a government agency, which can send help if needed. On the other side, that agency can track the results uploaded through uMED to keep tabs on the spread of a disease.</p>
<p>The uMED can be used to test for toxic metals in drinking water, to measure a patient’s blood-glucose and electrolyte levels, and even to quantify and diagnose malaria. It could also be used in the future to screen for other diseases, such as Ebola, HIV, E. Coli, hepatitis, influenza, West Nile virus or Dengue fever.</p>
<p>There are already various low-cost devices that can be used to test patients’ health or to diagnose certain diseases. Pregnancy tests, blood-glucose tests and rapid malaria tests all have their uses but are often too limited in what they can detect. In general, diagnostic tests can be either versatile and accurate but expensive and complicated, or rapid and cheap but limited and insensitive. We believe our approach fuses the strengths of these technological extremes, and avoids their weaknesses.</p>
<h2>How it works</h2>
<p>Electrochemical detection is widely used to perform chemical testing in well-resourced laboratories. In this type of testing, a voltage applied to a chemical sample causes a reaction that yields a detectable flow of current. The reaction can be controlled to ensure the current produced is related to the concentration of the chemical sample. In this way, concentrations of various chemicals can be measured by interrogating the samples with electronics. </p>
<p>Apart from blood-glucose metres, though, these types of measurements typically need expensive and sophisticated instruments. We redesigned a laboratory electrochemical analyser from the ground up to be affordable and tailored it to specifically measure fluid samples with physiological concentrations. It was important to us that all these sophisticated functions could be offered in a single, automated, hand-held device that resembled a blood-glucose meter, because this device in particular is familiar to a lot of people around the world.</p>
<p>To build the uMED, we developed a custom electrochemical sensor compatible with the open-source development environment <a href="http://www.arduino.cc">Arduino</a>. This means the uMED can be easily adapted to local needs, and reprogrammed or updated with minimal training. We also added a vibration motor, similar to those found on cellphones, to mix samples when necessary. This eliminated the need for addition equipment that is typically necessary to stir samples during measurements. </p>
<p>Although the use of smartphones is rapidly rising, there remain almost three billion people in the world today who still use older technologies for communication, and according to market trends, that number is not set to decrease much over the next decade. That’s why we needed to make uMED compatible with even low-end phones. There is huge potential to improve the health of people and animals in countries where mobile phones are everywhere but high-tech infrastructure is not. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/55640/original/zsvwcjtj-1407126470.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/55640/original/zsvwcjtj-1407126470.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/55640/original/zsvwcjtj-1407126470.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=612&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55640/original/zsvwcjtj-1407126470.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=612&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55640/original/zsvwcjtj-1407126470.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=612&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55640/original/zsvwcjtj-1407126470.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=770&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55640/original/zsvwcjtj-1407126470.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=770&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55640/original/zsvwcjtj-1407126470.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=770&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 flow of information from a test taken at the point-of-care to a remote medical facility, and back.</span>
<span class="attribution"><span class="source">Alex Nemiroski</span></span>
</figcaption>
</figure>
<p>For most tests, all a healthcare worker needs to do is insert a strip containing a blood, urine, or water sample (or dip an electrode into the sample), select the test they want to perform, and make a phone call to send the results. These can be glucose test strips, screen-printed electrodes, ion-selective electrodes or <a href="http://gmwgroup.harvard.edu/pubs/pdf/1189.pdf">ultra-low-cost, paper-based electrodes</a>.</p>
<p>The uMED is still a work in progress, and we’re working with devices firm <a href="http://www.dfa.org/">Diagnostics For All</a> to improve its diagnostic capacity, particularly in difficult environments. Field trials will start in India soon, with the hope of moving towards a device that can make healthcare easier, even before the internet arrives in hard-to-reach areas.</p><img src="https://counter.theconversation.com/content/29460/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alex Nemiroski 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>Remote diagnostics is an emerging field that allows healthcare workers to perform tests on patient samples in the field and to get results interpreted by medical experts remotely. This is a groundbreaking…Alex Nemiroski, Postdoctoral Fellow, Harvard UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/300672014-08-04T20:42:07Z2014-08-04T20:42:07Z‘Hobbit’ more likely had Down Syndrome than a new species<figure><img src="https://images.theconversation.com/files/55636/original/ff66zp8d-1407124080.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The hominid skull that gave rise to _Homo floresiensis_ - but is it really a new species?</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/ncssm/9069198615">Flickr/NCSSM </a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Many people believe that what was found in Liang Bua Cave on the island of Flores in Indonesia in 2003-2004 was some variety of hobbit-like human or prehuman. Our <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1407385111">research published today</a> argues that it was more likely just one of the local island inhabitants suffering from a medical condition.</p>
<p>Those of a more technical bent will recall that the “hobbit” was given the scientific name, <em><a href="http://australianmuseum.net.au/Homo-floresiensis">Homo floresiensis</a></em>.</p>
<p>What actually was found was a sample of bones and stone tools. These things did not have specimen labels on them bearing any formal scientific name, and nothing about them could reasonably be reconstructed to look anything like the brave little beings at the centre of J.R.R. Tolkien’s masterpiece of fantasy literature, <a href="http://www.sparknotes.com/lit/hobbit/context.html">The Hobbit</a>.</p>
<p>Bones are discovered; taxonomic names are invented by researchers. Analogies with characters in works of literary fiction are marketing devices.</p>
<h2>What was found in the cave</h2>
<p>Inside cave deposits several metres thick were scattered and fragmented human bones and teeth. The only reasonably complete remains of a single individual, labelled LB1 and dated to about 18,000 years ago, consisted of one skull with the mandible, most leg bones, some upper limb bones and fragments of bones of the trunk. (See this <a href="http://www.dlt.ncssm.edu/tiger/360views/Hominid_Skull-Homo_Floresiensis-Hobbit_1200x900/index.html">3D image</a> of the skull.)</p>
<p>The skull had an unusually small braincase while the face and teeth were of normal size and form, comparable with those of people living now near the cave. Limb bones had very weak muscle markings and unusual proportions. Thigh bones were very short when compared to the feet. Feet were flat.</p>
<p>No second skull was found among the mostly broken bones of other individuals. These other fragments had a range of sizes, generally on the small side, but comparable with present-day local people and those who live on Palau and the Andaman Islands.</p>
<p>Since the cave lies on an island where stone tools go back to 1 million years, archaeologists interpreted an unusual-looking skeleton as the discovery of a new species. Initial reconstructions of brain size of 380ml and body height of 1.06m did not match modern humans. Nor did they agree with general trends in human evolution (see figure below).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/55642/original/dfzczdgn-1407127502.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/55642/original/dfzczdgn-1407127502.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/55642/original/dfzczdgn-1407127502.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=408&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55642/original/dfzczdgn-1407127502.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=408&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55642/original/dfzczdgn-1407127502.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=408&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55642/original/dfzczdgn-1407127502.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=513&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55642/original/dfzczdgn-1407127502.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=513&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55642/original/dfzczdgn-1407127502.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=513&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Brain size of LB1 (orange square) against brain sizes of all hominids that lived up to the end of the Ice Age.</span>
</figcaption>
</figure>
<h2>Not as small as first thought</h2>
<p>Those reconstructions turned out to be incorrect on further investigation. After cleaning the deposit from inside the brain cavity its volume increased to 430ml. After correcting for unusual proportions of thighs and using other bones the reconstructed stature increased to between 1.2m to 1.4m.</p>
<p>The excitement of the discovery of the new species resulted in a flurry of speculations as to its origins among people interested in human evolution. It was thought initially that the small brain and diminutive stature were a <a href="http://www.bbc.com/news/science-environment-22166736">result of island dwarfing</a> - a phenomenon known for some herbivores residing on smaller islands.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/55643/original/s8sxw7q9-1407128081.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/55643/original/s8sxw7q9-1407128081.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/55643/original/s8sxw7q9-1407128081.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/55643/original/s8sxw7q9-1407128081.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/55643/original/s8sxw7q9-1407128081.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/55643/original/s8sxw7q9-1407128081.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/55643/original/s8sxw7q9-1407128081.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/55643/original/s8sxw7q9-1407128081.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&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 authors Maciej Henneberg (left) and Robert Eckhardt (centre, behind): compare our body size to that of the Rampasasa people who live near the Liang Bua cave.</span>
</figcaption>
</figure>
<p>Then complex statistical analyses of skeletal measurements led to the conclusion that the ancestors of the species had to wander to Indonesia from Africa nearly 2 million years ago but leaving no traces along the way.</p>
<p>Immediately after the <a href="http://news.nationalgeographic.com.au/news/2004/10/1027_041027_homo_floresiensis.html">discovery’s announcement</a> in 2004, biological anthropologists, who were familiar with the mechanisms of human evolution and experienced in the study of diseases from skeletal remains of ancient people, realised that the skeleton dating to a time when anatomically modern humans lived in Indonesia displayed signs of a developmental syndrome.</p>
<p>For this reason they opposed the naming of the new species. Since 2005 access to the skeletal remains for re-study was strictly limited. Opponents of the new species theory had to work from notes and measurements taken during 2005 examination of all skeletal remains from the Liang Bua cave and from secondary sources.</p>
<h2>Looking for a diagnosis</h2>
<p>Regarding the bones themselves, it always is difficult to make a diagnosis of disease from ancient remains because they are incomplete. Medical laboratory tests can’t be run and, of course, there is no way to question the patient about symptoms.</p>
<p>A number of scientists initially proposed various diagnoses. It took us a decade to arrive at a diagnosis of <a href="http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Down_syndrome_explained">Down Syndrome</a>. </p>
<p>Although there are disagreements about the precise numbers for brain size and stature estimated from skeletal parts, and the explanations for these, from the beginning everyone has agreed that LB1 brain and body size are unusually small.</p>
<p>Our group’s additional early insight from late 2004 was that the skull of LB1 was <a href="http://www.pnas.org/content/103/36/13421.abstract">asymmetrical in several ways</a>, particularly in its face. Although we published measurements of the left-right facial disparities, curiously these data were denied or dismissed for several years – but they are matters of observation, not interpretation. Anyone can see them.</p>
<p>Members of our group sometimes are referred to as “<a href="http://www.scientificamerican.com/article/hobbit-hullabaloo/?page=2">Hobbit deniers</a>”. We think that this controversy has been perpetuated by “data deniers”. </p>
<p>Starting from small brain and body size combined with asymmetry, it was possible to find several hundred medical syndromes that were at least a partial match. We went through these – as, incidentally, did several other groups of able researchers in Australia and elsewhere.</p>
<p>More than a few syndromes seemed promising to others as well as to us. Each time, as we looked closer, some detail would not fit. We even went so far as to begin a clinical study of <a href="http://rarediseases.info.nih.gov/gard/6859/laron-syndrome/resources/1">Laron syndrome</a>.</p>
<p>Finally, after comparing the distribution of signs in various diseases, and using statistical data on body proportions of patients, we have arrived at the diagnosis of Down Syndrome. This was the only pathological condition that had all signs in agreement with what is present in LB1.</p>
<h2>No help from DNA</h2>
<p>DNA extracted from LB1 bones is too fragmentary to allow direct diagnosis, but significantly the only fragments recovered so far are of modern human type. No sequences of a different species could be found.</p>
<p>Down Syndrome results from duplication of some genetic material and produces small brain and short stature. It affects childhood development, causing “<a href="http://science.howstuffworks.com/life/evolution/atavism1.htm">atavisms</a>”, with some bodily characteristics resembling earlier stages of evolution. No wonder archaeologists were confused.</p>
<p>Skeletal remains of Down Syndrome people are known from archaeological sites. Such people, though disadvantaged, can be valuable members of families and communities and in the past survived to age 30-35 years. </p>
<p>The researchers who made the extraordinary claims of the new species’s discovery, and the science writers who spread them, overlooked an important rule central to scientific method: extraordinary claims require extraordinary evidence.</p>
<p>But simpler explanations must be considered first (the rule of parsimony). This is a key issue for rational thought and scepticism everywhere.</p><img src="https://counter.theconversation.com/content/30067/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>Many people believe that what was found in Liang Bua Cave on the island of Flores in Indonesia in 2003-2004 was some variety of hobbit-like human or prehuman. Our research published today argues that it…Maciej Henneberg, Professor of Anthropological and Comparative Anatomy, University of AdelaideRobert Eckhardt, Professor of Developmental Genetics and Evolutionary Morphology, Penn StateLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/294912014-07-21T19:20:44Z2014-07-21T19:20:44ZThe true cost of cattle is much, much higher than you imagine<p>That eating beef is environmentally costly is by now widely appreciated. But little has been done to curtail the amount of cattle farmed for meat consumption. To try and address this, my colleagues and I decided to calculate just how costly beef production is for the environment, and how it stacks up against pork, poultry, dairy and eggs. Our hope is that better knowledge of the environmental costs of raising animals for food will help improve both the dietary choices people make and agricultural policies.</p>
<p>Our research, which was published in the Proceedings of the National Academy of Sciences of the US, found that raising beef cattle is far more environmentally costly than poultry, pork, dairy or eggs. Per calorie, cattle requires on average <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1402183111">28 times more land and 11 times more water</a> to farm. Farming cattle releases five times more greenhouse gases and uses six times as much nitrogen as the average of other animal products. </p>
<p>When compared with staple plant foods, these ratios roughly double. So, a beef calorie requires about 50 times more land than a wheat calorie. By comparison, pork, poultry and eggs are all roughly on the same level of environmental cost. In terms of greenhouse gas emissions, water use and the levels of nitrogen discharge from fertiliser run-off, dairy is comparable to pork, poultry and eggs. </p>
<p>While it’s long been clear that vegetarian diets produce lower environmental costs than ones involving produce from animals, people are still intent on eating food derived from animals – and with ever-increasing gusto. Taking note of this, we sought to identify the types of animal-based food that are least environmentally harmful.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/54472/original/qgwdchwv-1405960421.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/54472/original/qgwdchwv-1405960421.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/54472/original/qgwdchwv-1405960421.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=231&fit=crop&dpr=1 600w, https://images.theconversation.com/files/54472/original/qgwdchwv-1405960421.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=231&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/54472/original/qgwdchwv-1405960421.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=231&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/54472/original/qgwdchwv-1405960421.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=290&fit=crop&dpr=1 754w, https://images.theconversation.com/files/54472/original/qgwdchwv-1405960421.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=290&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/54472/original/qgwdchwv-1405960421.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=290&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Environmental costs of animal foods in (l to r) land, water, greenhouse gas, and nitrogen, compared to common plant foods such as wheat, rice and potato (green text).</span>
<span class="attribution"><span class="source">Eshel/Shepon/Makov/Milo</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>The (environmental) cost of food</h2>
<p>Though numerous studies have addressed elements of this issue, they have mostly used data from individual farms, typically one or at most a handful. But farms differ markedly geographically, from season to season and year to year, and are thus not necessarily representative of the big picture. </p>
<p>By contrast, we used the reverse, top-down approach by analysing national level data. While previous studies mostly addressed one environmental burden at a time (typically greenhouse gas emissions, but also water or land use), we simultaneously addressed each of them in order to offer a multi-dimensional view of the environmental performance of the livestock industry in the US. </p>
<p>We measured greenhouse gas emissions, water and land use, and reactive nitrogen discharge levels from manure or fertiliser. <a href="http://www.wired.com/2008/05/reactive-nitrog/">Reactive nitrogen</a> is environmentally important because it is the most common cause of degradation in freshwater ponds, streams and lakes, and around coastlines where fertiliser run-off washed into rivers reaches the sea.</p>
<p>We address the five main animal based products in the American diet: dairy, beef, poultry, pork and eggs, calculating the environmental costs per nutritional unit, calorie or gram protein. Our key challenge was devising accurate values of how much land, water, and reactive nitrogen livestock required, and the amount of greenhouse gasses they emit.</p>
<p>Working out these estimates required navigating numerous subtleties. For example, grazing cattle in the arid to semi-arid western US uses an enormous amount of land, but little or no irrigation. Grain-fed feedlot cattle, by contrast, use much less land, but require cultivated grains that depend strongly on nitrogen fertiliser. We needed to fairly account for these differences across the country, while determining figures that reflect, approximately, the true environmental costs.</p>
<h2>Making better decisions</h2>
<p>These findings have a number of implications. First, this research can inform environmentally minded individuals so they can make environmentally better dietary choices. Perhaps more importantly, the paper can also help inform agricultural policy, in the US and worldwide. In a companion paper in the Journal of Agricultural Science (forthcoming) we have laid down a foundation for analysing the environmental costs of any diet, including plant-based diets and those of other nations. </p>
<p>Perhaps our key contribution is to highlight areas in which improvement is most likely, and where a focused effort is likely to yield the most desirable change. Applying these methods to global diets can help improve long term global food security in light of the effects of climate change, water and land shortage, and rising population.</p><img src="https://counter.theconversation.com/content/29491/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gidon Eshel is the principal of environmentalCalculations.com
</span></em></p>That eating beef is environmentally costly is by now widely appreciated. But little has been done to curtail the amount of cattle farmed for meat consumption. To try and address this, my colleagues and…Gidon Eshel, Research Professor of Environmental Science , Bard CollegeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/265412014-05-12T20:32:09Z2014-05-12T20:32:09ZThe health impact of childhood bullying can last a lifetime<figure><img src="https://images.theconversation.com/files/48283/original/fhmgrmhw-1399905588.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Bruises fade, but stress stays on.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-64076404/stock-photo-teenager-student-with-fear-at-his-school-selective-focus.html?src=0jYKShr0BcJplVj7vdxTIQ-1-75">Teenager bullying image via Helder Almeida/Shutterstock</a></span></figcaption></figure><p>It is still not clear how the experience of being bullied in childhood translates into long-lasting health problems. A <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1323641111">new US study</a> has found that victims of bullying have high levels of a protein in their bloodstream that is associated with fighting off an infection – even into early adulthood. This finding may help understand further the association between childhood bullying victimisation and poor health outcomes later. </p>
<p>Research has consistently shown that young victims of bullying show difficulties including symptoms of anxiety, depression and also <a href="http://www.ncbi.nlm.nih.gov/pubmed/19785920">conduct problems</a> and <a href="http://www.ncbi.nlm.nih.gov/pubmed/19414712">psychotic symptoms</a>. These problems related to children’s mental health can persist even after the bullying has stopped, <a href="http://ajp.psychiatryonline.org/data/Journals/AJP/0/appi.ajp.2014.13101401.pdf">sometimes up until mid-life</a>.</p>
<p>There are some hypotheses that bullying victimisation is a form of “toxic stress” that can have an impact on physiological responses to childhood adversity. In turn, these responses may help explain why some victims develop health problems. </p>
<p>Mental and physical health problems are often related and although young children are generally healthy, research has started to show that bullied children tend to become adults with health problems. </p>
<p>One such mechanism is the inflammatory response, measured by the release in the bloodstream of a protein called C-reactive protein (CRP). High levels of CRP is a generic response that indicates that the body is either fighting an infectious agent, reacting to an injury or responding to a chronic condition such as arthritis. </p>
<p><a href="http://www.ncbi.nlm.nih.gov/pubmed/18391129">Research has shown</a> that CRP can also be elevated among people who experienced maltreatment by an adult in their childhood. This suggests that the body reacts in a similar way to “toxic stress” as it does to an infection.</p>
<h2>Bullying as a ‘toxic stress’</h2>
<p>Knowing that bullying is associated with high levels of CRP is important for two reasons. First, it would provide further support that childhood bullying victimisation should be considered as a toxic stress alongside other forms of abuse including child maltreatment. Second, this would provide a novel lead for identifying new targets for various types of interventions aimed at reducing problems related to the experience of being bullied in childhood. </p>
<p>The <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1323641111">new findings</a> from the longitudinal <a href="https://devepi.duhs.duke.edu/gsms.html">Great Smoky Mountains Study</a> of 1,420 children in the US has looked at CRP levels in children involved in bullying as victims, bullies and bully-victims (participants who both bully others and were also bullied). The authors, led by William E. Copeland at Duke University Medical Center, tested whether study participants who were bullied between the age of nine and 16 showed high levels of CRP in adolescence, and also later in early adulthood. </p>
<p>Their results indicate that the participants who experienced several exposures to bullying had higher levels of CRP compared to participants who were not involved in bullying – either as victims, bullies or bully-victims. </p>
<p>These associations remained even after taking into account the participants’ prior CRP level and variables associated with CRP levels such as body mass index, medication and alcohol use. They also took into account variables linked to being involved in bullying, including maltreatment, family dysfunction, and anxiety disorders.</p>
<h2>Lasting into early adulthood</h2>
<p>The authors then looked at CRP levels as the study participants entered adulthood. They observed a similar pattern of findings: victims of bullying had higher levels of CRP compared to those who were not involved in bullying. Furthermore, participants who were repeatedly bullied showed the highest levels of CRP.</p>
<p>Surprisingly, participants who bullied others showed the lowest levels of CRP in early adulthood amongst all four groups of children examined in this study. These associations also remained after the researcher controlled for prior CRP, variables associated with CRP levels and variables associated with being involved in bullying.</p>
<p>We already know from previous research that being bullied in childhood “gets under the skin” and can influence other mechanisms in the body involved in the physiological responses to stress, such as the <a href="http://medical-dictionary.thefreedictionary.com/hypothalamic-pituitary-adrenal+axis">hypothalamic-pituitary-adrenal axis</a>. For example, bullied children show a blunted level of cortisol response – a hormone released under stress – when exposed to stress in a laboratory experiment. </p>
<p>A <a href="http://www.ncbi.nlm.nih.gov/pubmed/21621141">study of identical twin pairs</a> where one twin had been bullied but the other not has shown that while non-bullied twins had a normal increase of cortisol after experiencing a social stress laboratory, their bullied co-twins showed a blunted response. And the more severe and frequent the bullying, the lower the cortisol response. </p>
<p>The new Duke research on the inflammatory process adds to a growing body of evidence that demonstrates that we need to move away from the perception that bullying is harmless and part of normal growing up. Instead, bullying should be considered as another form of toxic stress with potentially profound effects on mental and physical health. These effects have been repeatedly observed in childhood and increasingly so in adolescence and in adulthood too.</p><img src="https://counter.theconversation.com/content/26541/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Louise Arseneault 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>It is still not clear how the experience of being bullied in childhood translates into long-lasting health problems. A new US study has found that victims of bullying have high levels of a protein in their…Louise Arseneault, Professor in Developmental Psychology at the Institute of Psychiatry, King's College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/263642014-05-07T14:20:03Z2014-05-07T14:20:03ZPlants respond to salt just like humans respond to pain<p>Icy winters and arid summers are creating salty soil. In some regions, increasing aridity concentrates naturally occurring salt in the soil, while in others, rising seawater has contaminated the groundwater with sea salt. New research suggests plants are <a href="http://www.pnas.org/content/early/2014/03/21/1319955111.abstract">riding a calcium wave</a> just to survive in the increasingly salty, or saline, soils that have become a problem the world over. </p>
<p>Humans have contributed to increased soil salinity, as land and water use alters water tables, and human-influenced climate change shifts rainfall and air temperature patterns. While it seems counter-intuitive, even field irrigation increases soil salinity. All water applied to the soil contains some salt. As plants are unable to absorb salt, once evaporation removes the water the plant cannot use what is left is the salt, which builds up over time.</p>
<h2>These roots weren’t made for walking</h2>
<p>During icy winters, salt is flung onto the ground in ever increasing quantities to manage snow and ice. Over the past 50 years the application of salt on roads and walkways has <a href="http://www.pnas.org/content/102/41/14487.full">increased dramatically</a>: in 1960, around three million tonnes of salt were spread on North American roads; today, that figure is 20 million tonnes.</p>
<p>Come spring, rain runoff carries salt from the road and shoulders onto surrounding soils and into the water table. The cumulative effects of salt application to roadways and walkways are marked. Some freshwater river watersheds have seen salt levels rise between 100% and 250%. And <a href="http://www.sciencedirect.com/science/article/pii/S0269749102004815">these levels rise every year</a>.</p>
<p>This poses a significant problem as salt is, generally speaking, toxic to plants – as many a school student will have conclusively demonstrated in classroom experiments, and “salting the earth” was a tactic used by victorious armies to punish their foes and make it harder to reinhabit the land.</p>
<p>Rooted to the spot, plants cannot escape the toxic effects of salt, so rising salinity is a serious risk to both crop production, and more widely an entire ecosystem’s health.</p>
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<p>Recent <a href="http://www.pnas.org/content/111/17/6497.short">research</a> by Won-Gyu Choi and his colleagues, in the laboratory of <a href="http://www.botany.wisc.edu/gilroy/Site/Welcome.html">Simon Gilroy</a> at the University of Wisconsin, has found that calcium plays a key element in plants’ initial response to salt. When plants sense salt they respond by creating a “calcium wave”, an elevated concentration of calcium ions that passes in a ripple from the point of salt perception, throughout the plant. The wave is created by the release of calcium that the plants store within their cells.</p>
<p>The study’s authors used a novel system to observe changes in calcium within plant cells, by engineering plants that would create a protein that fluoresces according to the level of calcium present.</p>
<p>When they exposed plant roots to various stimuli including cold, touch, or stress, the plants generally responded with elevated calcium concentrations at the point of application. When roots sensed salt, calcium rose at the point of contact, followed by neighbouring cells in a continuous wave travelling at two cells per second throughout the plant. The calcium wave travelled from the roots all the way to the tips of the shoots and leaves above ground within two minutes.</p>
<h2>Plants get the message</h2>
<p>When the plants’ shoots received the signal, they altered what they were doing. In fact, they mounted what might best be described as a defence response. Having received the calcium wave message, plant tissues reconfigured their cellular functions – manufacturing new molecules that help the plant contend with salt, by adjusting water balance within the plant, and setting up barriers to salt invasion of the plant tissues. The authors are certain that it was the calcium wave that created this response by using chemicals that inhibited the passage of calcium.</p>
<p>Won-Gyu Choi and colleagues speculated that the calcium is released from a special compartment within the cell, stored for this purpose. This requires the action of special proteins, which form a pore that opens in order to release calcium from the compartment.</p>
<p>Examining plants where the pore proteins no longer functioned, they found the calcium wave no longer travelled properly through the plant. Without the ability to create this calcium wave transmission, they found those plants were unable to mount a defence against salt. These plants also exhibited poor growth in the presence of salt relative to normal plants.</p>
<p>Won-Gyu Choi and colleagues discovery has revealed an important mechanism that plants use to contend with salty soil. The calcium wave that plants create in their roots to inform the rest of the plant that salty times are ahead has striking similarities to our nervous system. </p>
<p>In humans, <a href="http://www.sciencedirect.com/science/article/pii/S0896627312001729">calcium is also used to signal</a> from one neuron to another when we experience stress, such as pain. When you get salt in a wound, the signals your brain receives also have a calcium wave element to them, as firing neurons trigger each other in a chain reaction that carries information from peripheral nerves to the brain in a fraction of a second. It turns out plants are using an analogous system to transmit information about salt stress, but rather than being received by a centralised brain, they inform every cell of the plant’s body. </p>
<p>Hopefully, we will be able to use this information in future to help plants alleviate the stress caused by salty soils and better contend with a saline environment – as long as we’re planning to eat plants, or animals that feed on them, we will need to give them all the help we can.</p><img src="https://counter.theconversation.com/content/26364/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Malcolm Campbell receives funding from the Natural Sciences and Engineering Research Council of Canada and from Genome Canada.</span></em></p>Icy winters and arid summers are creating salty soil. In some regions, increasing aridity concentrates naturally occurring salt in the soil, while in others, rising seawater has contaminated the groundwater…Malcolm Campbell, Professor & Vice-Principal Research, University of TorontoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/253012014-04-29T14:06:54Z2014-04-29T14:06:54Z‘Supershedding’ cows could be the biggest cause of E. coli<figure><img src="https://images.theconversation.com/files/46843/original/jwm4jgdc-1398175910.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Looks so innocent but is she a supershedder? </span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/b3d_/7065584959/sizes/l">b3d_</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Poisoning by E. coli is too familiar. As far as food-poisonings go, it’s one of the most serious and is frequently fatal in children and the elderly. Infection can also lead to lifelong kidney damage and acute kidney failure. One of the worst outbreaks <a href="http://www.independent.co.uk/news/fall-of-a-butcher-they-called-a-good-man-1313143.html">saw 21 people die</a> in Wishaw, Scotland in 1996. </p>
<p>Infection is caused by the <em>Escherichia coli</em> bacteria, and certain strains <a href="http://www.hpa.org.uk/webc/hpawebfile/hpaweb_c/1194947360190">produce a dangerous toxin</a> that can cause illness in humans. The worst of these is E. coli 0157, a pathogen that is transmitted from animal to human. Cattle are the main reservoir for the pathogen as cows harbour the bacteria in their gastrointestinal tract without becoming ill or showing any symptoms. Although it can spread between people, the usual routes of infection are either via the consumption of contaminated food and water, or by contact with livestock faeces. </p>
<p>If we are to control the spread of such diseases, we have to become better at identifying the major sources of risk in their spread. However, our understanding of how disease spreads across species boundaries is typically poor, which makes control difficult. </p>
<p>One idea is to vaccinate cattle. Vaccines have already been developed but their adoption is being hampered by licensing delays. Medical and veterinary agencies also have conflicting responsibilities. Those responsible for licensing vaccines in animals must typically show that a new control is not just safe, but that it improves the health of animals receiving it; this poses a problem for zoonotic pathogens that are benign in their reservoir hosts. It is also not easy to test a control measure used in animals against the outcome of a reduction in human illnesses, and this lack of data hampers effective decision-making when it comes to policy.</p>
<p>It is also difficult to mathematically model transmission of infection in animals to humans. Different factors such as the infectiousness of cattle, pathogen strains and infection routes, mean it’s not as simple as just measuring how much E. coli there is in cattle and using this to predict the risk for humans.</p>
<h2>‘Supershedding cows’</h2>
<p>But so-called “supershedding” might be one way of tackling the problem. Supershedding is a rare but epidemiologically important process where some cows are responsible for much more disease transmission than others. In the case of E. coli, some cattle shed the pathogen in faeces at unusually high concentrations. This is important because, despite being relatively rare, supershedders appear to be the major source of E. coli in the environment, from where other animals and humans can become infected.</p>
<p><a href="http://www.pnas.org/content/early/2013/09/10/1304978110">A recent study</a> in PNAS we published looked at this link between supershedding in cattle and transmission risk to humans. We found that although relatively rare, it was these cows that were significantly contributing to human risk. We used mathematical modelling to predict the impact of vaccination on the number of human cases. This was based on observations of more human cases associated with strains shed at high densities and fewer cases from strains shed at low densities. This information allowed us to predict the reduction in human cases from using vaccines that reduce high shedding.</p>
<p>This new understanding of animal-to-human transmission means a potential new way to target vaccines better. Vaccines could be used to reduce the frequency of bacterial shedding by particular cattle and also the number of bacteria shed when this happens. By doing this, the benefit to people from cattle vaccination should be substantially greater than previously anticipated by blanket vaccination. Our study showed that vaccines that cut shedding frequency in half could reduce human cases by nearly 85%, and could be an especially effective public health control against a serious disease.</p>
<p>In addition to the challenge of finding the best way to deal with the problem, it’s clear that veterinary and public health agencies aren’t helping by acting in apparent conflict. What the E. coli finding shows is the need for an understanding of animal and human health to be fundamentally integrated, rather than treated as discrete issues to be dealt with by separate organisations. It is only in this way that we can link together animal health findings to preventing infection in people.</p><img src="https://counter.theconversation.com/content/25301/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Louise Matthews 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>Poisoning by E. coli is too familiar. As far as food-poisonings go, it’s one of the most serious and is frequently fatal in children and the elderly. Infection can also lead to lifelong kidney damage and…Louise Matthews, Senior Research Fellow in the Institute of Biodiversity, Animal Health and Comparative Medicine, University of GlasgowLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/258342014-04-29T11:45:40Z2014-04-29T11:45:40ZOut of Africa: modern humans left the home continent in at least two waves<figure><img src="https://images.theconversation.com/files/47166/original/r6cxv2hp-1398693137.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Modern Papuans have descended from beachcombers.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/cifor/6239955953">cifor</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>It is <a href="https://theconversation.com/albert-and-adam-rewrite-the-story-of-human-origins-15835">well established</a> that modern humans originated in Africa, before moving out to inhabit rest of the planet. They first spread into Asia and Europe via the Arabian Peninsula, and those in the Far East eventually reached America and the Pacific islands. </p>
<p>However, this simple picture does not explain several groups found across Asia and Oceania. Now, by looking at genetic and archaeological data, researchers think they might have found the answer, confirming theories that humans migrated out of Africa more than once.</p>
<p>Across Asia, people are usually similar in appearance to those around them. However, there are scattered populations on <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3487975/">islands</a> and in other isolated areas that look quite distinct. These people are sometimes collectively called Negritos (while this may sound archaic, it is the <a href="http://www.nature.com/ejhg/journal/v19/n2/abs/ejhg2010162a.html">accepted scientific term</a>). Along with Papuans, Melanesians and aboriginal Australians, they are generally much darker-skinned and curlier-haired than their neighbours.</p>
<p>One explanation is offered by the “beachcomber” theory. The first modern humans that settled in Arabia were probably east African fisher-folk who crossed the Red Sea in boats. In this new land they stuck to their coastal lifestyle, rather than head inland for a whole new set of challenges. As their numbers increased, with the sea as a reliable food source and with boats for mobility, they could spread very quickly along the coast of South Asia, crossing inlets and reaching islands, until they eventually found and populated Australia. Later, inland Asian lifestles could become established and support much larger populations, which could spread south, replacing or absorbing our beachcombers in all but the most isolated locations.</p>
<p>This neat hypothesis seemed to have the problem solved until genetic studies were done, which grouped each Negrito population with its neighbours, rather than with other Negritos and Australasians. So why the similar appearance? Could it be that they have each separately evolved the same set of useful traits to live in a similar hot, coastal environment, in which case why have their neighbours not done the same? </p>
<p>A new study published in the <a href="http://dx.doi.org/10.1073/pnas.1323666111">Proceedings of the National Academy of Sciences</a>, tackled this conflicting evidence. Scientists used mathematical modelling to explain the genetics as well as the skull shapes observed across many Asian and Australasian populations. This involved testing several alternate histories to see which one is best able to explain the modern situation. Each model must be simple enough to understand, and between them, they must cover the likely possibilities.</p>
<p>The models tested could be described as:</p>
<ol>
<li>A population travelled eastwards inland and spread south from there</li>
<li>A population travelled along the beachcomber route and then spread north</li>
<li>A population took each route without interbreeding</li>
<li>A population took each route, they met and interbred</li>
</ol>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/47183/original/xr6vmtz7-1398714009.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/47183/original/xr6vmtz7-1398714009.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/47183/original/xr6vmtz7-1398714009.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/47183/original/xr6vmtz7-1398714009.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/47183/original/xr6vmtz7-1398714009.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/47183/original/xr6vmtz7-1398714009.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/47183/original/xr6vmtz7-1398714009.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/47183/original/xr6vmtz7-1398714009.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&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 four models charted.</span>
<span class="attribution"><span class="source">Reyes-Centeno/PNAS 2014</span></span>
</figcaption>
</figure>
<p>The reality is, of course, much more complicated, with millions of individuals living, travelling and breeding with no idea of an overall pattern. To this day, people leave Africa (and settle there), or in other words, there have been many, many out-of-Africa migrations. Nevertheless, identifying the model that best explains your observations can give you a good approximation of the most significant truths.</p>
<p>The study found that the fourth model best explained both the genetic data and the skulls for the Negrito population. This means that there were at least two significant out-of-Africa migrations contributing to today’s populations – one taking a coastal route and the other an inland route. </p>
<p>Negrito populations appear to have a mixture of beachcomber and inland ancestry. Australians, Melananesians and Papuans seem to descend from beachcombers alone. While other Asian populations – including Dravidian speakers, the majority of south Indians, also sometimes suggested as descendants of beachcombers – appeared to descend predominantly from the inlanders.</p>
<p>The timing, however, was crucial. If the Australasians had no inlander ancestry, they must have passed through Asia before the inlanders appeared. And indeed it appears they did. </p>
<p>A timescale was fitted to the model, using both archaeological evidence and the accumulation of genetics differences between modern populations. This suggests that, not only did the beachcombers arrive in Australia around 50,000 years ago (when the inland route was just starting out), but that they left Africa around 130,000 years ago. </p>
<p>This is much earlier than most previous estimates, and relatively soon after the first evidence of <a href="https://theconversation.com/what-makes-us-human-genetics-culture-or-both-14505">modern humans</a> (around 200,000 years ago). Intriguingly, from 135,000 years ago, East Africa was struck by a series of “megadroughts”. Perhaps it were these that triggered beachcombers to look for pastures new.</p><img src="https://counter.theconversation.com/content/25834/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel Zadik 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>It is well established that modern humans originated in Africa, before moving out to inhabit rest of the planet. They first spread into Asia and Europe via the Arabian Peninsula, and those in the Far East…Daniel Zadik, Postdoctoral researcher in genetics, University of LeicesterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/249862014-03-31T19:49:36Z2014-03-31T19:49:36ZHappily disgusted? It could show all over your face<figure><img src="https://images.theconversation.com/files/45131/original/4wss4k5s-1396239251.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Truly expressing yourself is more complex than you might think.</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/donatopirolo/8622914148/sizes/l">donatopirolo/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>Your face plays an important role in the <a href="http://en.wikipedia.org/wiki/Facial_feedback_hypothesis">experience</a> and <a href="http://bcs.worthpublishers.com/psychsim5/Expressing%20Emotion/PsychSim_Shell.html">expression</a> of emotion. Yet despite the complexity of the human face, which has 43 muscles in all, most of existing facial expression research focuses on <a href="http://education-portal.com/academy/lesson/ekmans-six-basic-emotions-list-definitions-quiz.html#lesson">six “basic” emotions</a>: happiness, surprise, sadness, anger, fear and disgust.</p>
<p>In a study <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1322355111">published today</a> in the Proceedings of the National Academy of Sciences, researchers from Ohio State University sought to expand the focus to a much more varied set of faces. </p>
<p>Their goal was to develop rules for these complex states and build a computer algorithm to identify them, with an eye, presumably, towards developing <a href="http://en.wikipedia.org/wiki/Machine_learning">machine learning</a> capabilities and <a href="https://theconversation.com/your-smartphone-is-looking-at-you-but-can-it-read-your-emotions-23908">making smart devices smarter</a>. </p>
<p>Amazingly, the algorithm was able to correctly guess those complex facial expressions more than three-quarters of the time.</p>
<h2>Express yourself</h2>
<p>We feel happy when joking with friends, sad when we lose a loved one and disgust when we come across something rotten in the fridge. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/45120/original/55b3qyyg-1396235862.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/45120/original/55b3qyyg-1396235862.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/45120/original/55b3qyyg-1396235862.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/45120/original/55b3qyyg-1396235862.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/45120/original/55b3qyyg-1396235862.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/45120/original/55b3qyyg-1396235862.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/45120/original/55b3qyyg-1396235862.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">… or see a banana eat a banana.</span>
<span class="attribution"><a class="source" href="http://www.flickr.com/photos/orangegreenblue/10350805026/sizes/l">Kat Northern Lights Man/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>Our emotional experience can also be much more complex. We might feel happy for a close work colleague when she gets promoted, but also disappointed that we were passed over. For scientific investigation of emotion, it is important to account for such complexity.</p>
<p>The researchers of today’s study proposed that more complex emotions (what they called “compound emotions”) are combinations of basic emotions. For example: </p>
<ul>
<li>hatred is a combination of anger and disgust</li>
<li>awe is a combination of fear and surprise.</li>
</ul>
<p>The authors reasoned that perhaps the facial expressions of these complex states are combinations of the displays representing “basic” emotions. In other words, if you added elements of an angry face to those of a disgusted face, you’d end up with a face that conveys hatred.</p>
<h2>Facial gymnastics</h2>
<p>As a first step, the researchers collected photos of people posing faces associated with emotions. Some 230 participants were given an emotion word (such as “disgust”), an example of a situation that might elicit that emotion (such as “a foul odour”) and a photo of someone else making the expression. A photo of each of 22 posed faces (six basic, 15 compound and one neutral) were snapped.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/45066/original/yk7zvnf5-1396223892.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/45066/original/yk7zvnf5-1396223892.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/45066/original/yk7zvnf5-1396223892.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=678&fit=crop&dpr=1 600w, https://images.theconversation.com/files/45066/original/yk7zvnf5-1396223892.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=678&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/45066/original/yk7zvnf5-1396223892.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=678&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/45066/original/yk7zvnf5-1396223892.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=851&fit=crop&dpr=1 754w, https://images.theconversation.com/files/45066/original/yk7zvnf5-1396223892.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=851&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/45066/original/yk7zvnf5-1396223892.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=851&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 facial expressions of basic and compound emotions. From left to right and top to bottom, these correspond to: happy, sad, fearful, angry, surprised, disgusted, happily surprised, happily disgusted, sadly fearful, sadly angry, sadly surprised, sadly disgusted, fearfully angry, fearfully surprised, fearfully disgusted, angrily surprised, angrily disgusted, disgustedly surprised, hatred and awed.</span>
<span class="attribution"><span class="source">Aleix M. Martinez</span></span>
</figcaption>
</figure>
<p>The resulting 5,060 photos were evaluated using a popular coding system in emotion research called the Facial Action Coding System, or <a href="http://www.paulekman.com/facs/">FACS</a>. The coding scheme notes which facial muscles are moved in an expression, such as nose wrinkling in the “disgust” pose.</p>
<p>The compound emotion expressions did indeed appear to be combinations of the muscle changes associated with their componential counterparts – see the “happily disgusted” expression below. (If you’re curious as to what “happily disgusted” means, researcher Aleix Martinez described it as: “how you feel when you watch one of those funny ‘gross-out’ movies and something happens that’s really disgusting, but you just have to laugh because it’s so incredibly funny.”)</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/45067/original/nv8jsjhq-1396223910.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/45067/original/nv8jsjhq-1396223910.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/45067/original/nv8jsjhq-1396223910.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=300&fit=crop&dpr=1 600w, https://images.theconversation.com/files/45067/original/nv8jsjhq-1396223910.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=300&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/45067/original/nv8jsjhq-1396223910.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=300&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/45067/original/nv8jsjhq-1396223910.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=377&fit=crop&dpr=1 754w, https://images.theconversation.com/files/45067/original/nv8jsjhq-1396223910.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=377&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/45067/original/nv8jsjhq-1396223910.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=377&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Here, a study participant makes three faces: happy (left), disgusted (centre) and happily disgusted (right).</span>
<span class="attribution"><span class="source">The Ohio State University</span></span>
</figcaption>
</figure>
<p>One of the interesting observations from evaluating the facial expressions is that some of compound emotion poses required conflicting muscle movements. Clearly, it would be impossible to simultaneously have one’s lips parted for happiness and lips pressed together for disgust in “happily disgusted”. </p>
<p>A number of unique muscle movements were also observed in some compound states (lips were parted in 43% of actors displaying sadly disgusted, despite lips parting not being a component of the sad or disgusted basic emotion expression).</p>
<h2>Interface-to-face</h2>
<p>After the photos were analysed, it was time to test whether a computer could accurately identify the compound facial expressions. </p>
<p>The research team wrote and trained a computer algorithm using similar emotion expression data from other research groups, then they set the algorithm loose on their 5,060 photos of basic and compound posed emotions.</p>
<p>How did the computer do? The algorithm was highly successful at identifying the basic emotion expressions (96.86% correct) and slightly less successful at identifying the compound emotion expressions (76.91% correct).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/45129/original/k2n5kmzj-1396237381.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1024%2C683&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/45129/original/k2n5kmzj-1396237381.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1024%2C683&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/45129/original/k2n5kmzj-1396237381.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/45129/original/k2n5kmzj-1396237381.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/45129/original/k2n5kmzj-1396237381.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/45129/original/k2n5kmzj-1396237381.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/45129/original/k2n5kmzj-1396237381.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/45129/original/k2n5kmzj-1396237381.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"></span>
<span class="attribution"><a class="source" href="http://www.flickr.com/photos/charlieeclark/6076117048/sizes/l">charliebarker/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Is there an app for that?</h2>
<p>So what does this mean for the promise of computers detecting our emotions? Does the ability to classify compound emotion expressions mean smart devices will become smarter? The answer is a confident “yes – and no”.</p>
<p>Recognising that human emotional life is far more complex than a small set of emotions is an important first step in improving technology at the human-machine interface. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/45074/original/jvvx69qg-1396225591.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/45074/original/jvvx69qg-1396225591.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/45074/original/jvvx69qg-1396225591.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=573&fit=crop&dpr=1 600w, https://images.theconversation.com/files/45074/original/jvvx69qg-1396225591.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=573&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/45074/original/jvvx69qg-1396225591.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=573&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/45074/original/jvvx69qg-1396225591.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=720&fit=crop&dpr=1 754w, https://images.theconversation.com/files/45074/original/jvvx69qg-1396225591.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=720&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/45074/original/jvvx69qg-1396225591.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=720&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">FIG. 21. — Horror and Agony, from Charles Darwin’s The Expression of the Emotions in Man and Animals.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Expression_of_the_Emotions_Figure_21.png">Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>Demonstrating that computers can be trained to identify more complex emotion expressions speaks to the potential ability of computers to, at some point in the future, recognise what we are communicating with our faces – but a number of critical questions remain.</p>
<p>First, in this study, as in many others, researchers used posed faces. This means that they asked people to move their faces in certain ways by prompting them with emotion words, hypothetical scenarios and visual examples. </p>
<p>Existing evidence suggests that <a href="http://smg.media.mit.edu/classes/Identity2004/FernandezDolsAndRuizBelda.pdf">adults</a> and <a href="http://www.researchgate.net/publication/235615554_Preschooler%27s_faces_in_spontaneous_emotional_contextshow_well_do_they_match_adult_facial_expression_prototypes/file/79e41511e7cc145d9c.pdf">children</a> very rarely make such caricatured faces, calling into question their utility at the human-computer interface. </p>
<p>Yes, we might be able to get computers to classify those faces. But if people don’t generate them outside the lab, this technology will have limited utility.</p>
<p>Second, the concept of compound emotions remains entirely theoretical — do people experience these states in the first place? <a href="http://www.gruponem.com/wp-content/uploads/2010/02/Oceja-Carrera-09.pdf">Other research</a> has uncovered the nuanced nature of “mixed” emotional experience, and there is <a href="http://www.researchgate.net/publication/8603001_The_agony_of_victory_and_thrill_of_defeat_Mixed_emotional_reactions_to_disappointing_wins_and_relieving_losses/file/32bfe510726b680ff2.pdf">debate</a> about whether mixed emotions even exist. </p>
<p>Regardless, the next time you find yourself in a happy yet disgusting situation, try to catch a glimpse of your face – it could be what your “happily disgusted” looks like.</p><img src="https://counter.theconversation.com/content/24986/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>Your face plays an important role in the experience and expression of emotion. Yet despite the complexity of the human face, which has 43 muscles in all, most of existing facial expression research focuses…Lisa A Williams, Lecturer, School of Psychology, UNSW SydneyEliza Bliss-Moreau, Research Fellow, University of California, DavisLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/244612014-03-17T19:35:47Z2014-03-17T19:35:47ZChickens tell tale of human migration across Pacific<figure><img src="https://images.theconversation.com/files/44068/original/pfy5h3q9-1395028272.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Wild chickens are everywhere in Hawaii but how did they get there?</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/jaybergesen/2268539580/sizes/o/">Flickr/jaybergesen</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Holiday in Hawaii and one of the birds you’re most likely to encounter is the chicken. You find them everywhere from beaches, to car parks and on walks through the bushland.</p>
<p>The locals warn that your chance of ever catching one are slim as these are wild birds, not the tame domestic kind found in farmyards and garden coops.</p>
<p>But chickens are not native to the Hawaiian islands, so how did they get there?</p>
<h2>Why did the chicken cross the Pacific?</h2>
<p>They were brought as part of the early human migration across the Pacific, and we have used ancient chicken bones to try to gain new insights into this process, with the <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1320412111">results published</a> today in the Proceedings of the National Academy of Sciences, USA.</p>
<p>The colonisation of the remote Pacific was one of the great feats of human navigation. It started in <a href="http://books.google.com.au/books?id=DSyqVAW04VIC&pg=PR14&lpg=PR14&dq=maritime+southeast+asia&source=bl&ots=3jB9KtpgCC&sig=NRpiYI-8m4AK0odSnQCeqkDw2bQ&hl=en&sa=X&ei=HIQmU5_-OMSllQWM6YDoBg&redir_esc=y#v=onepage&q&f=false">Island Southeast Asia</a> potentially in Taiwan, the Philippines, or Indonesia and moved across the vast expanse of ocean as far as Rapa Nui (Easter Island).</p>
<p>Although this is one of the most recent of major human migrations we still know relatively little about the routes or the processes involved. We also don’t know whether the eastward margin of this movement ended up contacting South America.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/44079/original/5qjfm84c-1395031416.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/44079/original/5qjfm84c-1395031416.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/44079/original/5qjfm84c-1395031416.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=262&fit=crop&dpr=1 600w, https://images.theconversation.com/files/44079/original/5qjfm84c-1395031416.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=262&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/44079/original/5qjfm84c-1395031416.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=262&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/44079/original/5qjfm84c-1395031416.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=329&fit=crop&dpr=1 754w, https://images.theconversation.com/files/44079/original/5qjfm84c-1395031416.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=329&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/44079/original/5qjfm84c-1395031416.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=329&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Feral rooster outside Makauwahi cave, Hawaii, where some of our ancient chicken samples came from.</span>
<span class="attribution"><span class="source">David Burney.</span></span>
</figcaption>
</figure>
<p>The first major oceanic human migration across the Pacific was the colonisation of western Polynesia (including Vanuatu, Fiji, Tonga, Samoa) around 3,250-3,100 years ago by the <a href="http://archaeology.about.com/b/2009/02/02/tracking-human-migration.htm">Lapita</a> culture, who are generally thought to be the ancestors of the Micronesian and Polynesian cultures.</p>
<p>The Lapita culture was characterised by a <a href="http://www.metmuseum.org/toah/hd/lapi/hd_lapi.htm">distinctively decorated</a> type of pottery, with the term “Lapita” originally based on archaeologist’s mishearing of the New Caledonian word “xapeta’a” – to dig a hole, or the place where one digs.</p>
<p>The colonisation of western Polynesia occurred only a few hundred years after the emergence of the distinctive pottery tradition in the Bismarck Archipelago, east of New Guinea, around 3,200 years ago, although its antecedents can be traced back to Island Southeast Asia.</p>
<h2>The long pause</h2>
<p>The initial movement into Western Polynesia was followed by a prolonged 1,800-year hiatus, or “pause” before further colonisation. This was perhaps related to the need to develop the navigational skills needed to cross the vast ocean barrier to the east (from Samoa to the Society Islands is 2,400km).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/44053/original/fxfdkjqt-1395021708.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/44053/original/fxfdkjqt-1395021708.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/44053/original/fxfdkjqt-1395021708.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/44053/original/fxfdkjqt-1395021708.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/44053/original/fxfdkjqt-1395021708.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/44053/original/fxfdkjqt-1395021708.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/44053/original/fxfdkjqt-1395021708.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/44053/original/fxfdkjqt-1395021708.jpg?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">Map showing the Bismarck Archipelago, western Polynesia (circled) and the eastern Polynesian triangle.</span>
</figcaption>
</figure>
<p>Following this, the remarkable navigational achievement of colonising the remote East Polynesian triangle, from Hawaii to Rapa Nui to New Zealand (an oceanic region roughly the size of North America) then occurred rapidly, in less than 300 years.</p>
<p>The huge expanse of empty ocean between these islands makes this a truly remarkable example of human technical ingenuity, and highlights the exploration capability of traditional pre-European cultures.</p>
<p>While human genetic signatures would provide the most accurate picture of these migrations, the population structures of many Pacific islands have been disrupted following European colonisation, and ancient skeletons are not common and have cultural taboos.</p>
<p>As a result, like in many other areas of the world, early human migrations have been tracked through the genetic signatures of the domestic animals and species such as pigs, rats and various plants they carried with them. These species are far more common in the archaeological record, and their study is free of many cultural restrictions.</p>
<h2>The chicken run</h2>
<p>We have used this approach to study the colonisation of the Pacific by sequencing DNA from ancient chicken bones recovered from archaeological sites, such as volcanic caves and beach middens, as well as from feathers of birds living on the islands today.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/44069/original/fbg2nzhm-1395028636.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/44069/original/fbg2nzhm-1395028636.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/44069/original/fbg2nzhm-1395028636.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/44069/original/fbg2nzhm-1395028636.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/44069/original/fbg2nzhm-1395028636.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/44069/original/fbg2nzhm-1395028636.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/44069/original/fbg2nzhm-1395028636.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/44069/original/fbg2nzhm-1395028636.jpg?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">View of Makauwahi Cave, Kaua`i, Hawai’i – a sinkhole site which produced many ancient Polynesian chicken bones containing DNA.</span>
<span class="attribution"><span class="source">Alec Burney</span></span>
</figcaption>
</figure>
<p>All of the ancient samples, and many of the modern birds, featured a characteristic Pacific genetic signature that is found nowhere else in the world apart from Island Southeast Asia. We have traced this lineage back at least as far as the Philippines, providing new clues about the origins of the Lapita peoples.</p>
<p>We also found that contamination with modern chicken DNA had misled a <a href="http://www.pnas.org/content/104/25/10335.abstract">previous study</a> that concluded there had been contact between Polynesians and pre-Columbian South America. That was based on similarities in ancient chicken DNA in each area.</p>
<p>We had already challenged these results because the genetic sequences involved were a common worldwide signature (which we informally call the “KFC sequence”) and provide no indication about past geographic connections. But when we re-analysed bones used in the earlier study we actually obtained entirely different results – only signs of the distinctive Pacific genetic signature. </p>
<h2>The South America connection</h2>
<p>Does this mean that there was no contact between Polynesians and pre-Columbian South America? All we can say is that the chicken sequences provide no support for the idea.</p>
<p>The presence of sweet potatoes in pre-European Polynesia has been seen as a strong indication of some form of contact. But plants and seeds can be also be dispersed by floating across large distances.</p>
<p>Recent work suggests this as the explanation for the African originated bottle gourd in South America, rather than the traditional view of <a href="http://www.pnas.org/content/early/2014/02/06/1318678111.abstract">human mediated dispersal</a>.</p>
<p>Apart from marine dispersal by floating, it is also possible that Polynesians obtained the sweet potato through maritime trade, without coming into direct contact with the South American mainland. Early Spanish records detail the presence of large floating trading posts off the coast of Peru and Chile – think of the 1995 movie <a href="http://www.imdb.com/title/tt0114898/">Waterworld</a> without the annoying jetskis (two words joined at the hip).</p>
<p>So – what else do we now know? Well, one surprising result is that we found that chickens with the original Lapita/Polynesian genetic signatures are still present on many isolated Pacific islands such as the Solomon Islands, Marquesas and even more central spots such as Vanuatu.</p>
<p>This early domestic breed may contain valuable genetic diversity for modern poultry flocks which have become genetically impoverished during industrialised farming, and are at considerable risk from diseases such as avian influenza. </p>
<p>Who would have thought that the basket of birds at the bottom of an ocean-going canoe in the middle of the Pacific might one day end up on our plates?</p><img src="https://counter.theconversation.com/content/24461/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alan Cooper receives funding from the Australian Research Council, the New Zealand Marsden Fund, and National Geographic Society.</span></em></p><p class="fine-print"><em><span>Vicki Thomson 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>Holiday in Hawaii and one of the birds you’re most likely to encounter is the chicken. You find them everywhere from beaches, to car parks and on walks through the bushland. The locals warn that your chance…Alan Cooper, Director, Australian Centre for Ancient DNA, University of AdelaideVicki Thomson, Postdoctoral Research Associate, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.