tag:theconversation.com,2011:/africa/topics/brain-fingerprinting-21415/articlesBrain fingerprinting – The Conversation2017-09-25T20:04:10Ztag:theconversation.com,2011:article/838742017-09-25T20:04:10Z2017-09-25T20:04:10ZMind-reading technology should not be used to solve crime<figure><img src="https://images.theconversation.com/files/185772/original/file-20170913-3782-833nte.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Brain-reading technology can still be tricked.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/closeup-ct-scan-brain-skull-on-107572736?src=t1Jn3hoHnJKYjeZNaHLEMA-1-5">Shutterstock/SvedOliver</a></span></figcaption></figure><p>There is growing interest in the potential for a technology known as brain fingerprinting to be used in the fight <a href="http://www.abc.net.au/news/2017-06-23/brain-finger-printing-could-revolutionise-criminal-trials/8647462">against crime</a> and <a href="http://www.smh.com.au/comment/scanning-for-terrorism--brain-fingerprinting-offers-new-hope-in-antiterrorism-fight-20160106-gm08k1.html">terrorism</a>, but it’s far from reliable.</p>
<p>Its use without consent violates human rights. And importantly, the technology (as it currently exists) can be tricked.</p>
<p>Brain fingerprinting seeks to detect deception by essentially reading thoughts. It works by using electroencephelography (EEG) to read the electrical activity of the brain, with the aim of trying to identify a phenomenon known as the <a href="https://www.ncbi.nlm.nih.gov/pubmed/1464675">P300 response</a>. </p>
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Read more:
<a href="https://theconversation.com/can-we-predict-who-will-turn-to-crime-63047">Can we predict who will turn to crime?</a>
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<p>The P300 response is a noticeable spike in the brain’s electrical activity, which usually occurs within <a href="https://www.google.com/patents/US7376459">one-third of a second</a> of being shown a familiar stimulus. The idea is that our subconscious brain has an uncontrollable and measurable response to familiar stimuli that the machine can register.</p>
<p>Imagine, for example, that a particular knife was used in a murder, and police show an image of it to their lead suspect who denies the crime. If the suspect registers a P300 response and thus a positive recognition of the knife, this would seem to suggest he’s lying. Alternatively, if the suspect doesn’t register a positive recognition, maybe police have the wrong guy.</p>
<p>It isn’t hard to see why this procedure might be enticing for law enforcement, but, as I explored in a <a href="http://journals.sagepub.com/toc/aljb/0/0">recent journal article</a>, they should be wary. </p>
<h2>Human rights concerns</h2>
<p>Most Australians would agree that they have a right to privacy, a right not to incriminate themselves, and a right to freedom of thought. Brain fingerprinting threatens all three.</p>
<p>The right to privacy usually protects us from police intrusions without a warrant into our home, our car, our body, or (at least in the United States) our <a href="https://www.nytimes.com/2014/06/26/us/supreme-court-cellphones-search-privacy.html?mcubz=0">mobile phone</a>. It seems almost obvious that if we have privacy in these physical things, then surely we deserve privacy in <a href="http://scholarship.law.duke.edu/faculty_scholarship/2654/">our innermost thoughts</a>.</p>
<p>As Tim Robbins said in The Shawshawnk Redemption: </p>
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<p>There are places in the world that aren’t made out of stone … there’s something inside that they can’t get to and they can’t touch. That’s yours.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/YM7y5KrS4QI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The Shawshank Redemption.</span></figcaption>
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<p>The <a href="http://www6.austlii.edu.au/cgi-bin/viewdoc/au/cases/cth/HCA/2001/25.html">right against self-incrimination</a>, otherwise known as the right to silence, protects us from being compelled to bear witness against ourselves if doing so might implicate us in a crime. Surely it should also protect us from someone reaching in and <a href="http://scholarship.law.duke.edu/faculty_scholarship/2651/">taking our thoughts by force</a>.</p>
<p>We also expect to have <a href="http://www6.austlii.edu.au/cgi-bin/viewdoc/au/legis/vic/consol_act/cohrara2006433/s14.html">freedom of thought</a>.</p>
<p>This right has not received much attention from courts, but until recently the idea that anyone could tamper with or steal our thoughts was more science fiction than fact. This is no longer the case. </p>
<p>In 2011, for example, <a href="http://news.berkeley.edu/2011/09/22/brain-movies/">researchers at the University of California</a> were able to teach a computer to reconstruct a video someone was watching based only on their brain signals, and the results were remarkable.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/nsjDnYxJ0bo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Movie reconstruction from human brain activity.</span></figcaption>
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<p>But if brain fingerprinting were to become a part of the police’s investigative toolkit, this could force suspects to take the extreme step of trying to erase or suppress their memories.</p>
<p>Which brings us to our next question: can we suppress or erase our memories?</p>
<h2>Tricking the technology</h2>
<p>Around Australia, most jurisdictions expressly <a href="http://www.austlii.edu.au/au/legis/nsw/consol_act/lda1983144/s6.html">prohibit the use</a> of polygraph evidence in court proceedings, in large part because of how fallible the technology is. It can be tricked by anyone with <a href="https://www.livescience.com/33512-pass-lie-detector-polygraph.html">a thumb tack</a>. </p>
<p>Brain fingerprinting was supposed to fix this issue. If you read someone’s subconscious brain responses before they have a chance to alter their physiology, theoretically they shouldn’t be able to trick the machine.</p>
<p>But there are already two plausible ways to do so.</p>
<p>First, research now suggests that a person can <a href="http://www.sciencedirect.com/science/article/pii/S0301051113001154">intentionally suppress</a> their memories and reduce the chances of the brain fingerprinting machine registering a positive response.</p>
<p>Second, researchers have discovered that beta-blockers such as propranolol (which was originally used to treat heart disease) can sometimes <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3050592/">block memory formation</a>. Theoretically, a wily offender could take the drug after committing a crime and effectively erase (or at least dull) their memory of the event.</p>
<p>For anyone interested in testing this theory, the technology’s inventor Larry Farwell has apparently <a href="http://www.larryfarwell.com/brain-fingerprinting-100,000-dollar-reward-dr-larry-farwell-dr-lawrence-farwell.html">offered US$100,000</a> to anyone who can “beat” a brain fingerprinting test.</p>
<h2>Courts should steer clear</h2>
<p>Worryingly, it’s possible that brain fingerprinting could be used in Australia to contribute to the “<a href="http://www.tai.org.au/content/tough-crime">tough on crime</a>” rhetoric. The headlines practically write themselves: “Got away with it? <em>Think</em> again!”.</p>
<p>Indeed, <a href="http://www.abc.net.au/news/2017-06-23/brain-finger-printing-could-revolutionise-criminal-trials/8647462">researchers in New Zealand</a> are currently hoping that their research into brain fingerprinting might have the potential to help police solve crimes.</p>
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Read more:
<a href="https://theconversation.com/virtual-child-pornography-could-both-help-and-hinder-law-enforcement-82746">Virtual child pornography could both help and hinder law enforcement</a>
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<p>And there may very well be situations where this sort of technology can be useful – for example, as a means of narrowing down the likely location of an imminent terrorist attack.</p>
<p>But extreme caution is needed. This technology has the potential to violate fundamental human rights, and because it has not yet proved itself to be infallible, it is simply too soon to start making Orwellian thought crimes a reality.</p>
<p>Police should be wary of using brain fingerprinting to investigate crime. And, at least for now, courts should be opposed to admitting brain fingerprinting evidence in criminal proceedings.</p><img src="https://counter.theconversation.com/content/83874/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Paul McGorrery 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>Most Australians would agree they have a right to privacy, a right not to incriminate themselves, and a right to freedom of thought. Brain fingerprinting threatens all three.Dr Paul McGorrery, PhD Candidate in Criminal Law, Deakin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/802632017-08-02T08:39:33Z2017-08-02T08:39:33ZIf a brain can be caught lying, should we admit that evidence to court? Here’s what legal experts think<figure><img src="https://images.theconversation.com/files/180175/original/file-20170728-23788-guf82w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Functional magnetic resonance imaging could reveal whether someone knows something they're not telling.</span> <span class="attribution"><a class="source" href="http://journal.frontiersin.org/article/10.3389/fneur.2013.00016/full">John Graner et al/Frontiers in Neurology</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>A man is charged with stealing a very distinctive blue diamond. The man claims never to have seen the diamond before. An expert is called to testify whether the brain responses exhibited by this man indicate he has seen the diamond before. The question is – should this information be used in court?</p>
<p>Courts are reluctant to admit evidence where there is considerable debate over the interpretation of scientific findings. But a <a href="https://academic.oup.com/jlb/article/3796509/The-limited-effect-of-electroencephalography?searchresult=1">recent study from researchers in the US</a> has noted that the accuracy of such “mind reading” technology is improving. </p>
<p>There are various methods of detecting false statements or concealed knowledge, which vary greatly. For example, traditional “lie detection” relies on measuring physiological reactions such as heart rate, blood pressure, pupil dilation and skin sweat response to direct questions, such as “did you kill your wife?” Alternatively, a <a href="http://theconversation.com/brain-scanners-allow-scientists-to-read-minds-could-they-now-enable-a-big-brother-future-72435">functional magnetic resonance imaging (fMRI)</a> approach uses brain scans to identify a brain signature for lying. </p>
<p>However, the technology considered by the US researchers, known as “brain fingerprinting”, “guilty knowledge tests” or “concealed information tests”, differs from standard lie detection because it claims to reveal the fingerprint of knowledge stored in the brain. For example, in the case of the hypothetical blue diamond, knowledge of what type of diamond was stolen, where it was stolen, and what type of tools were used to effect the theft.</p>
<p>This technique gathers electrical signals within the brain through the scalp by electroencephalography (EEG), signals which indicate brain responses. Known as the <a href="https://www.rroij.com/open-access/the-p300-wave-of-eventrelatedpotential.php?aid=34978">P300 signal</a>, those responses to questions or visual stimuli are assessed for signs that the individual recognises certain pieces of information. The process includes some questions that are neutral in content and used as controls, while others probe for knowledge of facts related to the offence. </p>
<p>The P300 response typically occurs some 300 to 800 milliseconds after the stimulus, and it is said that those tested will react to the stimulus before they are able to conceal their response. If the probes sufficiently narrow the focus to knowledge that only the perpetrator of the crime could possess, then the test is said to be “accurate” in revealing this concealed knowledge. Proponents of the use of this technology argue that this gives much stronger evidence than is possible to get through human assessment.</p>
<p>Assuming this technology might be capable of showing that someone has hidden knowledge of events relevant to a crime, should we be concerned about its use?</p>
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<img alt="" src="https://images.theconversation.com/files/176612/original/file-20170703-4580-1c1nqcr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/176612/original/file-20170703-4580-1c1nqcr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=499&fit=crop&dpr=1 600w, https://images.theconversation.com/files/176612/original/file-20170703-4580-1c1nqcr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=499&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/176612/original/file-20170703-4580-1c1nqcr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=499&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/176612/original/file-20170703-4580-1c1nqcr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=627&fit=crop&dpr=1 754w, https://images.theconversation.com/files/176612/original/file-20170703-4580-1c1nqcr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=627&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/176612/original/file-20170703-4580-1c1nqcr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=627&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">How private are our memories?</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/cute-girl-colorful-glowing-photo-memories-246693712?src=wiIuEZYLCMwWJVX1yAjxjQ-1-18">ESB Professional/Shutterstock</a></span>
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<h2>Potential for prejudice</h2>
<p>Evidence of this sort has not yet been accepted by the English courts, and possibly never will be. But similar evidence has been admitted in other jurisdictions, including India. </p>
<p>In the Indian case of <a href="http://www.nytimes.com/2008/09/15/world/asia/15brainscan.html">Aditi Sharma</a> the court heard evidence that her brain responses implicated her in her former fiancé’s murder. After investigators read statements related and unrelated to the offence, they claimed her responses indicated experiential knowledge of planning to poison him with arsenic, and of buying arsenic with which to carry out the murder. The case generated much discussion, and while she was initially convicted, this was later overturned. </p>
<p>However, the Indian Supreme Court has <a href="http://www.thehindu.com/migration_catalog/article16297234.ece/BINARY/Supreme%20Court%20judgement%20on%20narco-analysis%20test%20(833%20Kb)">not ruled out the possibility of such evidence being used</a> if the person being tested freely consents. We should not forget that people may knowingly conceal knowledge of facts relevant to a crime for all sorts of reasons, such as protecting other people or hiding illicit relationships. These reasons for hiding knowledge may have nothing to do with the crime. You could have knowledge relevant to a crime but be totally innocent of that crime. The test is for knowledge, not for guilt.</p>
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<a href="https://images.theconversation.com/files/176644/original/file-20170703-17450-u7v7lb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/176644/original/file-20170703-17450-u7v7lb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/176644/original/file-20170703-17450-u7v7lb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=705&fit=crop&dpr=1 600w, https://images.theconversation.com/files/176644/original/file-20170703-17450-u7v7lb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=705&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/176644/original/file-20170703-17450-u7v7lb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=705&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/176644/original/file-20170703-17450-u7v7lb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=886&fit=crop&dpr=1 754w, https://images.theconversation.com/files/176644/original/file-20170703-17450-u7v7lb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=886&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/176644/original/file-20170703-17450-u7v7lb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=886&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">How much weight is placed on neuroscientific evidence in the courtroom?</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/balance-weight-head-silhouette-graphic-design-330801134">Studio_G/Shutterstock</a></span>
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<h2>Context is key</h2>
<p>The US researchers looked at whether brain-based evidence might unduly influence juries and prejudice the fair outcome of trials. They found concerns that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2778755/">neuroscientific evidence may adversely influence trials</a> could be overstated. In their experiment, mock jurors were influenced by the existence of brain based evidence, whether it indicated guilty knowledge or the absence of it. But the strength of other evidence such as motive or opportunity weighed more heavily in the hypothetical jurors’ minds.</p>
<p>This is not surprising, as our <a href="https://academic.oup.com/jlb/article/2/3/510/1917949/The-use-of-neuroscientific-evidence-in-the?searchresult=1">case-based research</a> demonstrates the importance of the context in which neuroscientific evidence is introduced in court. It could help support a case, but the success is dependent on the strength of all the evidence combined. In no case was the use of neuroscientific evidence alone determinative of the outcome, though in several it was highly significant.</p>
<p>Memory detection technologies are improving, but even if they are “accurate” (however we choose to define that term) it does not automatically mean they will or should be allowed in court. Society, legislators and the courts are going to have to decide whether our memories should be allowed to remain private or whether the needs of justice trump privacy considerations. Our innermost thoughts have always been viewed as private; are we ready to surrender them to law enforcement agencies?</p><img src="https://counter.theconversation.com/content/80263/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>Using mind reading technologies in court could become common practice.Lisa Claydon, Senior Lecturer in Law, The Open UniversityPaul Catley, Head of Law School, The Open UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/487232015-10-12T17:53:55Z2015-10-12T17:53:55ZBrain activity is as unique – and identifying – as a fingerprint<figure><img src="https://images.theconversation.com/files/98089/original/image-20151012-17858-w4ne84.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">I knew that brain was yours.</span> <span class="attribution"><span class="source">Emily S Finn</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Each of us is unique, with our own strengths, weaknesses and idiosyncrasies. While this is a truism everyone grasps intuitively, it’s been difficult to determine if and how this individuality is reflected in brain activity.</p>
<p>To investigate, my colleagues and I looked at brain images from volunteers scanned using functional magnetic resonance imaging, or <a href="http://www.ndcn.ox.ac.uk/divisions/fmrib/what-is-fmri">fMRI</a>. This technique measures neural activity via blood flow in the brain while people are awake and mentally active. We calculated a “functional connectivity profile” for each person based on their individual patterns of synchronized activity between different parts of the brain.</p>
<p>In fact, it turns out that the ebb and flow of brain activity is like a fingerprint: each person has their own signature pattern, <a href="http://doi.org/10.1038/nn.4135">according to our study</a> just published in the journal Nature Neuroscience. Using only their connectivity profiles, we could identify individuals from a group. Based purely on these profiles, we could also predict how people would perform on one type of intelligence test.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/97989/original/image-20151011-9146-1irzyiq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/97989/original/image-20151011-9146-1irzyiq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/97989/original/image-20151011-9146-1irzyiq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/97989/original/image-20151011-9146-1irzyiq.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/97989/original/image-20151011-9146-1irzyiq.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/97989/original/image-20151011-9146-1irzyiq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/97989/original/image-20151011-9146-1irzyiq.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/97989/original/image-20151011-9146-1irzyiq.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>
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<span class="caption">An fMRI scanner uses a strong magnetic field to track blood flow in the brain.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Modern_3T_MRI.JPG">KasugaHuang</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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</figure>
<h2>Trading the forest for the trees</h2>
<p>fMRI is the best tool we have to study what goes on in a living, thinking human brain in a safe and noninvasive way. And yet fMRI data is notoriously noisy – lots of things influence the signal at any given time, and only some of them are related to the actual brain activity that we care about.</p>
<p>This is why, traditionally, fMRI studies average together data from many different people: the idea is that by finding common patterns of brain activity, we can get rid of much of the noise and end up with something closer to the “true” signal. Essentially, we blend all the individuals’ signals to get one version that’s representative of the whole population.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/97991/original/image-20151011-9150-1dp5m6l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/97991/original/image-20151011-9150-1dp5m6l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/97991/original/image-20151011-9150-1dp5m6l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=374&fit=crop&dpr=1 600w, https://images.theconversation.com/files/97991/original/image-20151011-9150-1dp5m6l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=374&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/97991/original/image-20151011-9150-1dp5m6l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=374&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/97991/original/image-20151011-9150-1dp5m6l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=470&fit=crop&dpr=1 754w, https://images.theconversation.com/files/97991/original/image-20151011-9150-1dp5m6l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=470&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/97991/original/image-20151011-9150-1dp5m6l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=470&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Usually researchers combine data from many fMRI scans to find the areas of the brain typically active during certain tasks.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:FMRI_scan_during_working_memory_tasks.jpg">John Graner</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>But you don’t need to be a brain scientist to recognize that everyone is different; this averaging probably obscures interesting activity patterns that are idiosyncratic to each person. And for fMRI to be practically useful – in medicine, for example – we’d need to get meaningful information based on a scan from a single person.</p>
<p>We set out to prove that analyzing fMRI data from individual people is indeed possible, by showing that these idiosyncratic activity patterns are reliable enough to identify individuals from a large group.</p>
<h2>Analyzing individual scans</h2>
<p>We used data from the Human Connectome Project (<a href="http://www.humanconnectomeproject.org">HCP</a>), a major research effort to collect brain-imaging data along with behavioral, demographic and genetic information from a large number of healthy people. So far, data from 500 people have been released, and there are plans to collect 1,200 in total. All the data are made publicly available, so researchers anywhere can download it, analyze it in different ways, and mine it for interesting insights.</p>
<p>We looked at data from the first 126 <a href="http://humanconnectome.org/about/project/logistics-of-data-acquisition.html">participants in the HCP</a>. Each person was scanned six different times. During two of the scans, people were simply resting, letting their minds wander. During the other four scans, they worked on some type of cognitive task: trying to hold items in mind in a test of working memory, listening to a story, solving math problems, looking at emotional faces or moving different parts of their body.</p>
<p>To analyze the fMRI data for each individual participant, we first divided the whole brain into 268 separate regions. While it’s an open question just how many different functional regions there are in the brain, <a href="http://doi.org/10.1016/j.neuroimage.2013.05.081">previous work</a> of ours has shown that using between 200 and 300 regions lets us detect subtle effects, while still keeping things manageable in terms of the time and computing power it takes to run the analyses.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/97992/original/image-20151011-9117-9yh6nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/97992/original/image-20151011-9117-9yh6nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/97992/original/image-20151011-9117-9yh6nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=516&fit=crop&dpr=1 600w, https://images.theconversation.com/files/97992/original/image-20151011-9117-9yh6nu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=516&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/97992/original/image-20151011-9117-9yh6nu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=516&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/97992/original/image-20151011-9117-9yh6nu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=649&fit=crop&dpr=1 754w, https://images.theconversation.com/files/97992/original/image-20151011-9117-9yh6nu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=649&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/97992/original/image-20151011-9117-9yh6nu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=649&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 functional connections in the brain that were most distinguishing of individuals. Many were between the prefrontal (left side of image) and parietal (right side of image) lobes.</span>
<span class="attribution"><span class="source">Emily S Finn</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>For each pair of regions, we calculated the strength of the functional connection between them. To understand what a “functional connection” is, think of two musicians playing at the same time: rather than measuring how loudly each musician is playing, we measure how synchronized their playing is. It’s not about overall levels of activity in any single brain region, but rather how pairs of regions tend to increase and decrease their activity in tandem. We calculated this measure of synchrony for every pair of regions across a brain. For each person we had a functional connectivity profile for each of the six scans they underwent.</p>
<p>We wanted to see if connectivity profiles could act like fingerprints. So we took a single profile from one scan session – say, the working memory session – and compared it to all 126 profiles for a different scan session, say the one at rest. Based on the numerical profiles, we figured out which other profile was its closest match. Would we be able to match up the participant’s working memory and at-rest scans? That is, would an individual’s brain “look the same” no matter what task it was doing?</p>
<p>The majority of the time, the identity we had predicted was indeed the correct one: we were able to identify people with up to 99% accuracy. The accuracy ranged from 64% to 99%, depending the specific pair of scan sessions. If we were just randomly guessing, we would expect to choose the right identity less than 1% of the time, so this was a very significant result.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/98091/original/image-20151012-17807-j37bcb.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/98091/original/image-20151012-17807-j37bcb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/98091/original/image-20151012-17807-j37bcb.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=139&fit=crop&dpr=1 600w, https://images.theconversation.com/files/98091/original/image-20151012-17807-j37bcb.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=139&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/98091/original/image-20151012-17807-j37bcb.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=139&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/98091/original/image-20151012-17807-j37bcb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=175&fit=crop&dpr=1 754w, https://images.theconversation.com/files/98091/original/image-20151012-17807-j37bcb.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=175&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/98091/original/image-20151012-17807-j37bcb.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=175&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 networks highlighted out of the 268 brain regions – the medial frontal in purple and the frontoparietal in teal. These two networks were best for identifying people as well as predicting fluid intelligence.</span>
<span class="attribution"><span class="source">Emily S Finn/Xilin Shen</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Predicting fluid intelligence</h2>
<p>Certain connections were most distinguishing of individuals – namely, those between the brain’s prefrontal lobe (just behind the forehead) and parietal lobe (farther back on top of the head). These areas evolved most recently, and neuroscientists have long known that they are crucial for sophisticated functions like attention, memory and language. </p>
<p>We discovered that these connections could also predict how people would perform on a test of fluid intelligence, or on-the-spot reasoning ability. Fluid intelligence is the ability to see patterns and solve reasoning problems.</p>
<p>While the predictions of fluid intelligence were overall more accurate than not, there was still a fair amount of error – the model overpredicted some people’s scores and underpredicted others’ – so we certainly wouldn’t advocate giving someone a brain scan instead of an IQ test or other traditional assessment.</p>
<h2>Your brain scans are quintessentially you</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/97995/original/image-20151011-9113-6q5oaq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/97995/original/image-20151011-9113-6q5oaq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/97995/original/image-20151011-9113-6q5oaq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=758&fit=crop&dpr=1 600w, https://images.theconversation.com/files/97995/original/image-20151011-9113-6q5oaq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=758&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/97995/original/image-20151011-9113-6q5oaq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=758&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/97995/original/image-20151011-9113-6q5oaq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=952&fit=crop&dpr=1 754w, https://images.theconversation.com/files/97995/original/image-20151011-9113-6q5oaq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=952&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/97995/original/image-20151011-9113-6q5oaq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=952&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Brains – and connectivity profiles – are as unique as we are.</span>
<span class="attribution"><span class="source">Emily S Finn/Michael Hathaway</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>In the first part of our study, we found that people always look most like themselves, regardless of what they’re doing. In other words, the same brain doing two different tasks always looks more similar than two different brains doing the same task. And in the second part of our study, we saw that these connectivity profiles correspond to highly complex cognitive attributes.</p>
<p>Why does this matter? After all, we don’t need to put someone in an MRI scanner to know who they are – we can tell that by looking at them. The importance of this finding is that these connectivity profiles could potentially give us information about people that is harder to tell just by looking. </p>
<p>For example, they could help predict who is at risk for developing a disease. Maybe there’s something in the individual patterns of strong and weak brain connections that reveals how susceptible someone is to different neurological or mental illnesses, such as schizophrenia, depression or Alzheimer’s disease. If we collect fMRI images from people while they are still healthy, and then follow them over time to see who goes on to become ill, perhaps we can build a model relating parts of the connectivity profile to future health. Then we could apply this model to a brand-new person’s profile to predict their likelihood of getting sick. This could be a way to target and treat high-risk people early on, in hopes that intervening early will improve their outcomes.</p>
<p>Ultimately, we hope these profiles could someday be used in personalized medicine, a way to customize interventions and therapies for people based on their individual biology.</p>
<p>But there are still many open questions. For example, we tested identification between scans separated by a few days, but how stable are connectivity profiles over a period of months or years? Can they change as a function of aging, illness, cognitive training or some other process? What other behavioral traits are reflected in patterns of brain connectivity? While there is much work to be done, my colleagues and I believe that these results provide an exciting foundation for future research.</p><img src="https://counter.theconversation.com/content/48723/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emily S Finn receives funding from the National Science Foundation and the National Institutes of Health.</span></em></p>Typically, researchers pool a bunch of brain scans to figure out the average way brains handle certain tasks. Instead, could they pick out individual brain profiles from a stack of 126 people’s scans?Emily S Finn, PhD Candidate in Neuroscience, Yale UniversityLicensed as Creative Commons – attribution, no derivatives.