tag:theconversation.com,2011:/us/topics/face-blindess-3606/articlesFace blindess – The Conversation2024-03-28T18:54:37Ztag:theconversation.com,2011:article/2264302024-03-28T18:54:37Z2024-03-28T18:54:37ZA rare condition makes other people’s faces look distorted. Why a new case is important<p>If you’ve seen portraits painted by <a href="https://journals.sagepub.com/doi/10.1111/j.1468-2982.2000.00113.x">Pablo Picasso</a> or <a href="https://www.frontiersin.org/articles/10.3389/fnhum.2014.00581/full">Francis Bacon</a>, you might not be surprised to hear that both men may have suffered from a disorder that affects how faces are perceived. </p>
<p><a href="https://prosopometamorphopsia.faceblind.org/">Prosopometamorphopsia</a> (PMO) is a condition where faces appear distorted, and sometimes even demonic. In most cases, these distortions alter how images of faces look, as well as those seen in person. This makes it difficult for sufferers to assess the accuracy of illustrations depicting what they see because the illustration itself will appear distorted. </p>
<p>However, a case described in a <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00136-3/abstract">recent study</a> gave researchers new insight into PMO. Unlike most other cases, the 58-year-old man (referred to as VS) perceived images of faces without distortion. Unfortunately, when he saw people in person over the last 31 months, every face appeared stretched and “demonic” to him. </p>
<p>Not to be confused with <a href="https://theconversation.com/i-should-know-you-face-blindness-and-the-problem-of-identifying-others-8884">prosopagnosia</a> (poor face recognition but without visual distortions), PMO is thought to be extremely rare and people who have it perceive faces as drooping, stretched, out of position, or either smaller or larger than normal. These distortions might apply to the whole face, <a href="https://www.sciencedirect.com/science/article/pii/S0028393208004971">only one side</a>, or even be restricted to particular features like the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3540293/">nose and mouth</a>.</p>
<h2>What causes prosopometamorphopsia?</h2>
<p>In contrast with prosopagnosia, which can either be acquired (through injury, for example) or developmental (present from birth), PMO seems only to be the result of the former. A <a href="https://www.sciencedirect.com/science/article/pii/S0010945221000836">2021 study</a> by researchers in the Netherlands reviewed 81 cases of PMO. The causes included <a href="https://www.vinmec.com/en/news/health-news/brain-infarction-what-you-need-to-know/">brain infarction</a> (disrupted blood flow to part of the brain), <a href="https://www.ncbi.nlm.nih.gov/books/NBK559173/#:%7E:text=type%20of%20stroke.-,Hemorrhagic%20stroke%20is%20due%20to%20bleeding%20into%20the%20brain%20by,bleeding%20into%20the%20subarachnoid%20space.">haemorrhagic stroke</a> (bleeding into the brain), surgery complications, head injury, and brain tumour. However, in 24% of cases, there appeared to be no structural abnormalities to the brain. Instead, PMO was associated with other diagnoses like epilepsy, migraine and schizophrenia.</p>
<p>Reassuringly, in the majority of cases, people with PMO appear to recover from their condition. This might be either a full or partial recovery, sometimes resulting from treatments that address the underlying cause (such as anti-epileptic drugs for epilepsy, or surgery to remove a brain tumour). However, some people seem to recover without any intervention. The time for recovery ranges from hours to years, but the typical recovery period is often days to weeks. </p>
<h2>Is face recognition affected?</h2>
<p>Despite the fact that people with PMO sometimes experience seeing profound facial distortions, their ability to recognise faces rarely seems to be affected. However, sufferers may simply be relying on other cues to help with recognition, like the person’s voice or clothes. For some people, distortions only appear after seconds or minutes of seeing someone’s face, allowing them time to identify the person first. Researchers have also tried to model how PMO-like distortions could <a href="https://www.sciencedirect.com/science/article/pii/S0010945221003440">affect face recognition</a>. They found that the distance between the viewer and face played a significant role in how accurately faces were recognised by participants.</p>
<p>A <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00136-3/abstract">recent study</a> by researchers in New Hampshire, US, focused on the case of a man known as VS. He had a lesion in his <a href="https://www.britannica.com/science/hippocampus">hippocampus</a> (a region of the brain mainly associated with memory) but no other medical issues of note.</p>
<p>Although VS saw people’s faces as stretched and with deep grooves (in his words, appearing “demonic”), facial images were unaffected for him. The researchers presented VS with in-person faces and the same faces on a computer screen. Next, the researchers used image-editing software to modify each photo so that it matched VS’s descriptions, listening to his real-time feedback. </p>
<p>It was the first time researchers could create photorealistic visualisations of these kinds of distortions, providing a depiction of how people with PMO can see those around them.</p>
<p>VS’s distortions also appeared to be <a href="https://jov.arvojournals.org/article.aspx?articleid=2792559">affected by colour</a>, so researchers investigated what happened when VS viewed faces through coloured plastic filters. They found that green filters decreased, and red filters intensified, the distortions compared with the no-filter baseline. These results showed that colour filters worn in glasses could reduce face distortions in PMO, and that colour might affect how we perceive face shape in general.</p>
<h2>What can we learn?</h2>
<p>As researchers continue to build on our knowledge of PMO, it is likely that more insights will be revealed about how the general population processes faces. Among the <a href="https://www.sciencedirect.com/science/article/pii/S0028393223000519">many questions</a> yet to be answered, some involve how and where faces are represented in the human brain. We also still have a lot to learn about the specific nature of PMO’s distortions, what they can tell us, and why they seem to resolve themselves in some cases but not others. For now, PMO is both a fascinating and disturbing condition, and one that could potentially teach us a great deal about human face perception.</p>
<p>Given that PMO is so rare and we still have so much to learn about it, please consider getting in touch with me (the <a href="https://staff.lincoln.ac.uk/rkramer">author</a> of this article) if you think you may be suffering from it. Remember that those with PMO don’t really think that the world is distorted, and instead realise that their vision is different in some way.</p><img src="https://counter.theconversation.com/content/226430/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robin Kramer 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>A highly unusual new case is giving scientists insights about what causes illusions of facial distortionRobin Kramer, Senior Lecturer in the School of Psychology, University of LincolnLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1765892022-02-10T14:23:16Z2022-02-10T14:23:16ZFrom ‘super-recognisers’ to the ‘face blind’ – how tests reveal the underlying cognitive processes<figure><img src="https://images.theconversation.com/files/444773/original/file-20220207-23-1tnlfpp.jpg?ixlib=rb-1.1.0&rect=88%2C54%2C4477%2C3162&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">'Have we met?' Actor Brad Pitt thinks he is faceblind.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/venice-italy-august-29-brad-pitt-1527973523">Matteo Chinellato/Shutterstock</a></span></figcaption></figure><p>The ability to recognise faces is important in many different real life contexts and fundamental to our social relationships and interactions. It allows us to identify people we care about, and respond appropriately to them. We may greet a friend differently to our boss, for example. But some people are simply better than others at recognising faces.</p>
<p>At one end of the spectrum, there are people called “<a href="https://theconversation.com/facial-recognition-research-reveals-new-abilities-of-super-recognisers-128414">super-recognisers</a>”. They find face recognition easy – often successfully identifying people even if they have only seen them once, briefly or a long time ago. Conversely, people with “<a href="https://theconversation.com/always-forget-a-face-so-does-brad-pitt-dont-just-blame-your-memory-50334">developmental prosopagnosia</a>” are at the opposite end of the face recognition scale. They find it tricky to recognise faces and can therefore struggle to socially interact with those around them. </p>
<p>People with this type of “face blindness” may not realise they have it until they reach their teenage years or later. For most of us though, our face recognition ability falls between these extremes – we aren’t super-good, but we aren’t particularly bad either. </p>
<p>It may seem that face recognition is a single, isolated skill. But psychologists know that the ability depends on a number of different cognitive processes that interact in complex ways.</p>
<h2>Measuring face recognition</h2>
<p>If we are to test face recognition accurately, it is important that we know what it is. And it turns out that <a href="https://doi.org/10.1186/s41235-018-0112-9">different tests</a> may produce different results.</p>
<p>One task used to measure how good we are at determining identity in unfamiliar faces is called “face matching”, captured, for example, by the <a href="https://doi.org/10.3758/BRM.42.1.286">Glasgow Face Matching Test</a>. Here you are presented with two faces and asked whether they belong to the same person or different people. Performance across 40 pairs, ranges from being just over chance (guessing) to 100% correct. </p>
<p>Being good at face matching is particularly important for some jobs. Indeed, passport control officers verify identity by matching the identity of a live person to a photo in a passport.</p>
<p>But being good at face matching doesn’t necessarily make you a super-recogniser. Indeed some matching tasks may not be difficult enough to allow super recognisers to show off their skills. <a href="https://pubmed.ncbi.nlm.nih.gov/16169565/">The Cambridge Face Memory Test</a> is an example of a “face learning task”. It measures your ability to learn and identify previously unknown faces. Specifically, you memorise the faces of different people and then try to pick them out of a line-up of three faces. The test starts very easy and gets progressively more difficult. Doing well on this task depends on your ability to see the visual differences between faces and to memorise them. </p>
<p>Finally, we can test familiar face recognition. When recognising familiar faces, we are tapping into our stored long-term memories of known people. We may know them as a family member or friend, or it may be someone from our favourite TV show. Most <a href="https://link.springer.com/article/10.3758/PBR.16.2.252">familiar face recognition tasks</a> ask people to try to recognise famous faces either from current footage or use a test based on celebrity faces from before they were famous.</p>
<h2>Performance across tasks</h2>
<p>Interestingly, performance across different face tasks may be associated. So, if you are good at one face recognition task then you may also be good at other face tasks too. Some researchers <a href="https://pubmed.ncbi.nlm.nih.gov/28077292/">have proposed a general face factor</a> that accounts for some correspondence in performance across tasks. </p>
<p>But this is not necessarily the case. You can be good at one task but impaired at another. And this is where the complexity lies. For example, if you have problems with working memory then you may struggle with face learning and familiar face recognition, but not necessarily with face matching. Similarly, being impaired at long term memory may make it particularly difficult to access memories of familiar people. Finally, problems with attention may affect your everyday face recognition but have less impact in the lab when you are fully focused on the task in hand.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/444774/original/file-20220207-13-1bou5u9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A mosaic of hundres of faces." src="https://images.theconversation.com/files/444774/original/file-20220207-13-1bou5u9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/444774/original/file-20220207-13-1bou5u9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=346&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444774/original/file-20220207-13-1bou5u9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=346&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444774/original/file-20220207-13-1bou5u9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=346&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444774/original/file-20220207-13-1bou5u9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=435&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444774/original/file-20220207-13-1bou5u9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=435&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444774/original/file-20220207-13-1bou5u9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=435&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">We are bombarded by faces on a daily basis, which can be a challenge for those with poor memory.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hundreds-multiracial-people-crowd-portraits-headshots-1908066802">Andrew Angelov/Shutterstock</a></span>
</figcaption>
</figure>
<p>Given the different measures of face recognition, we need to clearly define how we determine when someone is impaired (or a super-recogniser). Certainly, there is no single accepted test to measure face recognition ability. Instead, psychologists think that its best to measure face recognition using multiple tasks, exploring the different aspects of face recognition. On each task, performance from an individual is compared to that achieved by a large population of the general public. </p>
<p>We must also listen to a person’s report of their face recognition ability in their everyday lives. Some people may score normally on, for example, the Cambridge Face Memory Test in the lab, but struggle to recognise their friends and family in the street. Conversely, while poor performance across a number of face recognition tests is a good indicator for prosopagnosia, it is not necessarily a clear diagnosis of it. </p>
<p>More valid measures of face recognition that reflect real life still need to be developed. In real life, face recognition is much more complicated. Most of the existing face tasks use still images of faces, whereas in the real world faces move in complex and subtle ways. The full picture will rely on tests that can distinguish more carefully between different types of face impairment.</p><img src="https://counter.theconversation.com/content/176589/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Karen Lander 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>No single test can accurately determine whether you are a super-recogniser.Karen Lander, Senior Lecturer in Experimental Psychology, University of ManchesterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/503342015-11-27T14:00:11Z2015-11-27T14:00:11ZAlways forget a face? So does Brad Pitt – don’t just blame your memory<figure><img src="https://images.theconversation.com/files/102153/original/image-20151117-21808-ufjql1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Meeting people out of context can be tricky</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-216292882/stock-photo-businessman-with-a-paper-bag-on-head-in-the-street.html?src=FqD1pQdRhcrm0faKFJFH0A-1-1">www.shutterstock.com</a></span></figcaption></figure><p>Most of us occasionally fail to recognise people we know. This often happens when we meet someone we know in an unusual context, such as bumping into a work colleague in a supermarket. Nevertheless, the ability to recognise another person from their face is something most of us take for granted. But what would life be like if everyone’s face looked the same to you? </p>
<p>There is growing recognition of a condition called <a href="http://www.nhs.uk/Conditions/prosopagnosia/Pages/Introduction.aspx">developmental prosopagnosia</a> (face-blindness). People with this condition have normal vision, but grow up with severe difficulties recognising faces. </p>
<p>Unlike cases of acquired prosopagnosia – where people have difficulty recognising faces later in life as a result of a stroke or an injury – people with developmental prosopagnosia experience lifelong face recognition problems despite having no brain injury. </p>
<p>Developmental prosopagnosia is an example of a neurodevelopmental condition, similar to dyslexia. Just as people with dyslexia grow up with problems reading words, people with developmental prosopagnosia grow up with problems reading faces. </p>
<p>Developmental prosopagnosia was thought to be extremely rare, but, as public awareness has increased, more and more sufferers have made their problems known to researchers. The latest estimates suggest that as many as 1 in 50 people may experience face recognition difficulties severe enough to affect their daily lives. Sadly, some people develop anxiety and depression as a result of the social difficulties they experience. </p>
<p>Well-known developmental prosopagnosics include the actor <a href="http://www.esquire.com/entertainment/movies/interviews/a22679/brad-pitt-cover-interview-0613/">Brad Pitt</a>, the co-founder of Apple, <a href="http://www.bbc.co.uk/news/technology-34188602">Steve Wozniak</a>, and the recently deceased author and neurologist, <a href="http://www.newyorker.com/magazine/2010/08/30/face-blind">Oliver Sacks</a>. </p>
<h2>Ways of coping</h2>
<p>Prosopagnosics often find alternative ways to recognise others. For example, many sufferers recognise a person by an unusual facial feature (such as a characteristic nose), voice, hairstyle, <a href="http://www.dailymail.co.uk/health/article-2641659/I-recognise-Grandfather-rare-face-blindness-condition-spot-wife-45-years-crowded-room.html">clothing</a>, or the way they <a href="http://www.theguardian.com/lifeandstyle/2008/nov/22/exp-erience-prosopagnosia-face-blindness-neurology">move</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/103171/original/image-20151125-23837-mvn6a6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/103171/original/image-20151125-23837-mvn6a6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/103171/original/image-20151125-23837-mvn6a6.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/103171/original/image-20151125-23837-mvn6a6.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/103171/original/image-20151125-23837-mvn6a6.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/103171/original/image-20151125-23837-mvn6a6.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/103171/original/image-20151125-23837-mvn6a6.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Unusual facial features can help prosopagnosics recognise people.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Gerard_Depardieu.JPG/1024px-Gerard_Depardieu.JPG">9EkieraM1/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>People with the condition sometimes wait for others to initiate conversation so they can identify them by their voice. Environments where people wear similar clothes, such as school or work uniforms, can make recognising others difficult. Also, sufferers may fail to recognise someone if they have changed their hairstyle or put on a hat. </p>
<p>At school, children with the condition can have problems recognising friends and teachers. As adults, some sufferers deliberately choose careers that don’t require frequent face-to-face contact – and many avoid potentially challenging social situations. </p>
<p>Prosopagnosics can have difficulty following films and TV shows due to problems recognising characters in different scenes. In severe cases, sufferers can even struggle to recognise <a href="http://www.dailymail.co.uk/health/article-2641659/I-recognise-Grandfather-rare-face-blindness-condition-spot-wife-45-years-crowded-room.html">partners and family members</a>. </p>
<p>Often prosopagnosics grow up blaming themselves, attributing their face recognition difficulties to a lack of focus or poor memory. Unfortunately, these sorts of interpretations may be reinforced by parents and teachers, unaware of the condition. However, face-blindness is unrelated to <a href="http://www.pnas.org/content/112/41/12887.abstract">general intelligence</a>, attention, and wider memory ability. Often, learning about their condition and finding out that they’re not alone comes as an enormous relief to sufferers.</p>
<p>While the causes of developmental prosopagnosia are not fully understood, studies using new imaging techniques have revealed subtle <a href="http://www.nature.com/neuro/journal/v12/n1/full/nn.2224.html">brain differences</a> in people with the condition. In particular, several brain regions known to play a role in face recognition appear to be under-connected in developmental prosopagnosia, possibly impairing information exchange within this network. </p>
<p>The condition probably has a genetic component. Often sufferers have a sibling or parent who also has difficulty recognising faces. Genetic or environmental factors that cause a person to develop face-blindness may increase their chances of developing other neurodevelopmental disorders. For example, developmental prosopagnosia appears to be more common in people with <a href="https://www.psychologytoday.com/blog/my-life-aspergers/201303/how-much-aspergers-is-really-face-or-emotion-blindness">autism</a>, than in the wider population. </p>
<h2>New diagnostic test</h2>
<p>Until recently, researchers relied on computer-based face-recognition tests (notably the <a href="http://www.sciencedirect.com/science/article/pii/S0028393205002496">Cambridge Face Memory Test</a>) to diagnose developmental prosopagnosia. However, completing computer based tests can be time-consuming and costly so there have been calls for a test that is easy to administer and can be used to screen large numbers of people. </p>
<p>Researchers at <a href="http://www.city.ac.uk/news/2015/november/city-academic-develops-test-to-diagnose-face-blindness">City University in London</a> have developed a <a href="http://www.troublewithfaces.org/test-yourself-1">self-report questionnaire</a> to help researchers and doctors identify people with developmental prosopagnosia. The questionnaire has 20 statements based on common experiences reported by sufferers. For example: “When I was at school I struggled to recognise my classmates” and: “When people change their hairstyle, or wear hats, I have problems recognising them”.</p>
<p>Respondents indicate how well each statement describes them on a five-point scale, giving a total score of between 20 and 100. When used alongside computer-based tests of face recognition ability, scores on the questionnaire can help researchers develop a profile of potential prosopagnosics, ensuring consistent, reliable diagnosis. </p>
<p>We are only just beginning to understand developmental prosopagnosia. The ability to screen large numbers of people will help researchers uncover the true extent of the condition – something that has, until now, been based on extrapolation and guesswork. By understanding its nature and origins, it may one day be possible to alleviate the symptoms. In the meantime, increasing awareness and understanding will help those for whom recognising others remains a daily challenge.</p><img src="https://counter.theconversation.com/content/50334/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Cook receives funding from the Economic and Social Research Council (ESRC). </span></em></p><p class="fine-print"><em><span>Federica Biotti 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>Face blindness is believed to be a fairly common condition but, until now, diagnosis has been complicated and expensiveRichard Cook, Senior Lecturer in Psychology, City, University of LondonFederica Biotti, PhD student in Cognitive Psychology and Neuroscience, City, University of LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/88842012-08-16T04:54:52Z2012-08-16T04:54:52ZI should know you: ‘face blindness’ and the problem of identifying others<figure><img src="https://images.theconversation.com/files/14312/original/39xr99zw-1345090388.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What do these two famous faces have in common?</span> <span class="attribution"><span class="source">Alex Hofford/Alan Porritt</span></span></figcaption></figure><p>Do you recognise the people in the picture above? They are, of course, <a href="http://en.wikipedia.org/wiki/Jane_Goodall">Jane Goodall</a> – British primatologist and anthropologist – and the actor, author and comedian <a href="http://en.wikipedia.org/wiki/Stephen_fry">Stephen Fry</a>.</p>
<p>Recognising the identity of these people from their faces may have seemed effortless. But for some people, recognising the faces of famous people is very difficult. In fact, such people often fail to recognise the faces of their children, spouse, parents, close friends, work colleagues and sometimes even themselves in a mirror.</p>
<p>This inability to recognise faces is known as “face blindness” or prosopagnosia (from Greek: “prosopon” = “face”; “agnosia” = “not knowing”). Prosopagnosia is not the same as forgetting names (which happens to everyone!), rather it’s the problem of not being able to use someone’s face to determine their identity.</p>
<p>The following quote from David Fine, a prosopagnosic whose story <a href="http://www.bmj.com/content/342/bmj.d1736.extract">appeared in the British Medical Journal in 2011</a>, illustrates just how severe prosopagnosia can be and the effects the condition can have on mental health, relationships and occupational success:</p>
<blockquote>
<p>“I often fail to recognise my children or even my wife … I have failed to acknowledge friends and, more distressingly, those in authority. </p>
<p>At school I would get lines for not raising my cap to a teacher … As a young man I ignored girls whom I had met the night before – not a good mating strategy. </p>
<p>I find networking all but impossible, and social situations, from parties to conferences, may cause acute anxiety… I know other staff members by their uniforms and badges. In party clothes, with different hairstyles, they are strangers to me.”</p>
</blockquote>
<p>People with prosopagnosia know they are looking at a face but the face does not convey information about identity. As such, people find they use other cues, such as voice, gait or context, to identify people. To quote David Fine again:</p>
<blockquote>
<p>“I memorise hair, jewellery, and favourite clothes. I recognise gaits, tics, and voices … Above all I rely on context: a person of a certain type in our corridor is my colleague — but in the supermarket is probably a stranger.”</p>
</blockquote>
<p>People with prosopagnosia can usually see perfectly well, and as such they can often tell other similar objects apart, such as two cars. Many people with prosopagnosia are also able to extract other types of information from faces, such as the expression displayed and the direction of the person’s eye gaze.</p>
<p>In these cases, prosopagnosia is a selective impairment in extracting identifying information from a face.</p>
<figure><a href="http://upload.wikimedia.org/wikipedia/commons/4/4e/Fusiform_gyrus_animation.gif"><img width="440px" src="http://upload.wikimedia.org/wikipedia/commons/4/4e/Fusiform_gyrus_animation.gif"></a><figcaption>Animation of the [fusiform](http://en.wikipedia.org/wiki/Fusiform_face_area) gyrus of the temporal lobe. Damage to this brain area can sometimes result in prosopagnosia.</figcaption></figure>
<h2>Acquired prosopagnosia</h2>
<p>Some cases of prosopagnosia are acquired, in which a person who was previously able to recognise faces has a traumatic brain injury – such as a stroke – which damages the parts of the brain used to recognise faces.</p>
<p>Many brain regions are involved in processing faces, however damage to regions involved in face and object processing in the occipital and temporal lobes (see image below) are most likely to result in prosopagnosia.</p>
<h2>Congenital prosopagnosia</h2>
<p>Cases of acquired prosopagnosia have been reported in the neurological literature since the mid-19th century. More recently, it has also become apparent that people can also have severe difficulty recognising faces without having a brain injury.</p>
<p>These people have what is known as congenital or developmental prosopagnosia and have failed to develop face identity recognition mechanisms. People with congenital prosopagnosia, such as David Fine, have been unable to recognise faces for as long as they can remember.</p>
<p>There are a number of high-profile individuals who have had lifelong face recognition difficulties. These include popular scientist <a href="http://www.abc.net.au/science/drkarl/">Dr. Karl Kruszelnicki</a>, portrait painter <a href="http://worldsciencefestival.com/videos/painting_blind">Chuck Close</a>, neuroscientist <a href="http://en.wikipedia.org/wiki/Oliver_Sacks">Oliver Sacks</a> and, as you may have guessed, the two people in the image at the top of this story: <a href="http://twitter.com/stephenfry/status/200914856931635201">Stephen Fry</a> and <a href="http://faceblind.livejournal.com/5325.html">Jane Goodall</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/14308/original/9m43sj4m-1345084594.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/14308/original/9m43sj4m-1345084594.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=428&fit=crop&dpr=1 600w, https://images.theconversation.com/files/14308/original/9m43sj4m-1345084594.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=428&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/14308/original/9m43sj4m-1345084594.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=428&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/14308/original/9m43sj4m-1345084594.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=538&fit=crop&dpr=1 754w, https://images.theconversation.com/files/14308/original/9m43sj4m-1345084594.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=538&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/14308/original/9m43sj4m-1345084594.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=538&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The lobes of the brain: the frontal lobe (blue), the parietal lobe (yellow), the temporal lobe (green) and the occipital lobe (pink).</span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
</figcaption>
</figure>
<p>In 2007, we established the <a href="https://www.maccs.mq.edu.au/research/projects/prosopagnosia/register/">Australian Prosopagnosia Register</a> where people who suspect they have congenital prosopagnosia are able to register their interest to participate in research. </p>
<p>These people report severe, recurring, everyday face recognition difficulties, such as failing to recognise their child at day care or having difficulty following the plot of movies because they cannot differentiate the actors.</p>
<p>The prevalence of congenital prosopagnosia is estimated at between 2-2.9% of the adult educated population. Given this, it’s perhaps not surprising that hundreds of people have registered with our website, and thousands of people have registered on similar <a href="http://faceblind.org/">registers in the US and UK</a>. </p>
<p>Thanks to the generosity of those who volunteer their time, we now know that congenital prosopagnosia sometimes runs in families, and therefore may have a genetic basis.</p>
<p><a href="http://dx.doi.org/10.1080/02643290802299350">Research has also shown</a> that people with prosopagnosia seem to have difficulty seeing the face as a whole and instead seem to focus on individual parts. Moreover, they may spend more time looking at parts of the face that aren’t that useful for distinguishing between faces – such as the hairline – rather than other regions which may be more diagnostic, such as the eyes.</p>
<p>Research is also beginning to reveal the neural basis of congenital prosopagnosia. And people are working on developing training programs that people with prosopagnosia can use to improve their face recognition.</p>
<p>So next time you see someone and instantly know who they are, consider yourself lucky: imagine if that never happened.</p><img src="https://counter.theconversation.com/content/8884/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Romina Palermo receives funding from the Australian Research Council.</span></em></p>Do you recognise the people in the picture above? They are, of course, Jane Goodall – British primatologist and anthropologist – and the actor, author and comedian Stephen Fry. Recognising the identity…Romina Palermo, Associate Professor, ARC Centre of Excellence in Cognition and its Disorders & School of Psychology, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.