Molly Crockett: Beware neuro-bunk

147,949 views ・ 2012-12-18

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Translator: Joseph Geni Reviewer: Morton Bast
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I'm a neuroscientist, and I study decision-making.
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I do experiments to test how different chemicals
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in the brain influence the choices we make.
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I'm here to tell you the secret to successful decision-making:
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a cheese sandwich.
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That's right. According to scientists, a cheese sandwich
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is the solution to all your tough decisions.
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How do I know? I'm the scientist who did the study.
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A few years ago, my colleagues and I were interested
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in how a brain chemical called serotonin
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would influence people's decisions in social situations.
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Specifically, we wanted to know how serotonin would affect
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the way people react when they're treated unfairly.
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So we did an experiment.
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We manipulated people's serotonin levels by giving them
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this really disgusting-tasting artificial lemon-flavored drink
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that works by taking away the raw ingredient for serotonin
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in the brain.
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This is the amino acid tryptophan.
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So what we found was, when tryptophan was low,
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people were more likely to take revenge
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when they're treated unfairly.
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That's the study we did, and here are some of the headlines
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that came out afterwards.
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("A cheese sandwich is all you need for strong decision-making")
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("What a friend we have in cheeses")
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("Eating Cheese and Meat May Boost Self-Control") At this point, you might be wondering, did I miss something?
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("Official! Chocolate stops you being grumpy") Cheese? Chocolate? Where did that come from?
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And I thought the same thing myself when these came out,
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because our study had nothing to do with cheese or chocolate.
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We gave people this horrible-tasting drink
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that affected their tryptophan levels.
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But it turns out that tryptophan also happens to be found
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in cheese and chocolate.
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And of course when science says cheese and chocolate
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help you make better decisions, well, that's sure to grab people's attention.
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So there you have it:
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the evolution of a headline.
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When this happened, a part of me thought, well,
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what's the big deal?
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So the media oversimplified a few things, but in the end,
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it's just a news story.
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And I think a lot of scientists have this attitude.
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But the problem is that this kind of thing happens all the time,
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and it affects not just the stories you read in the news
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but also the products you see on the shelves.
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When the headlines rolled, what happened was,
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the marketers came calling.
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Would I be willing to provide a scientific endorsement
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of a mood-boosting bottled water?
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Or would I go on television to demonstrate,
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in front of a live audience,
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that comfort foods really do make you feel better?
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I think these folks meant well, but had I taken them up on their offers,
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I would have been going beyond the science,
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and good scientists are careful not to do this.
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But nevertheless, neuroscience is turning up more and more in marketing.
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Here's one example: Neuro drinks,
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a line of products, including Nuero Bliss here,
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which according to its label helps reduce stress,
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enhances mood, provides focused concentration,
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and promotes a positive outlook.
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I have to say, this sounds awesome. (Laughter)
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I could totally have used this 10 minutes ago.
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So when this came up in my local shop, naturally I was
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curious about some of the research backing these claims.
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So I went to the company's website looking to find
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some controlled trials of their products.
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But I didn't find any.
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Trial or no trial, these claims are front and center
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on their label right next to a picture of a brain.
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And it turns out that pictures of brains have special properties.
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A couple of researchers asked a few hundred people
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to read a scientific article.
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For half the people, the article included a brain image,
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and for the other half, it was the same article
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but it didn't have a brain image.
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At the end — you see where this is going —
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people were asked whether they agreed
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with the conclusions of the article.
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So this is how much people agree with the conclusions
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with no image.
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And this is how much they agree with the same article
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that did include a brain image.
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So the take-home message here is,
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do you want to sell it? Put a brain on it.
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Now let me pause here and take a moment to say that
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neuroscience has advanced a lot in the last few decades,
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and we're constantly discovering amazing things
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about the brain.
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Like, just a couple of weeks ago, neuroscientists at MIT
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figured out how to break habits in rats
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just by controlling neural activity in a specific part of their brain.
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Really cool stuff.
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But the promise of neuroscience has led to some really
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high expectations and some overblown, unproven claims.
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So what I'm going to do is show you how to spot
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a couple of classic moves, dead giveaways, really,
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for what's variously been called neuro-bunk,
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neuro-bollocks, or, my personal favorite, neuro-flapdoodle.
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So the first unproven claim is that you can use brain scans
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to read people's thoughts and emotions.
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Here's a study published by a team of researchers
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as an op-ed in The New York Times.
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The headline? "You Love Your iPhone. Literally."
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It quickly became the most emailed article on the site.
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So how'd they figure this out?
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They put 16 people inside a brain scanner
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and showed them videos of ringing iPhones.
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The brain scans showed activation in a part of the brain
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called the insula, a region they say
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is linked to feelings of love and compassion.
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So they concluded that because they saw activation in the insula,
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this meant the subjects loved their iPhones.
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Now there's just one problem with this line of reasoning,
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and that's that the insula does a lot.
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Sure, it is involved in positive emotions
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like love and compassion,
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but it's also involved in tons of other processes,
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like memory, language, attention,
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even anger, disgust and pain.
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So based on the same logic, I could equally conclude
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you hate your iPhone.
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The point here is, when you see activation in the insula,
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you can't just pick and choose your favorite explanation
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from off this list, and it's a really long list.
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My colleagues Tal Yarkoni and Russ Poldrack
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have shown that the insula pops up in almost a third
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of all brain imaging studies that have ever been published.
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So chances are really, really good
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that your insula is going off right now,
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but I won't kid myself
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to think this means you love me.
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So speaking of love and the brain,
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there's a researcher, known to some as Dr. Love,
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who claims that scientists have found the glue
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that holds society together,
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the source of love and prosperity.
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This time it's not a cheese sandwich.
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No, it's a hormone called oxytocin.
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You've probably heard of it.
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So, Dr. Love bases his argument on studies showing
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that when you boost people's oxytocin,
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this increases their trust, empathy and cooperation.
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So he's calling oxytocin "the moral molecule."
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Now these studies are scientifically valid,
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and they've been replicated, but they're not the whole story.
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Other studies have shown that boosting oxytocin
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increases envy. It increases gloating.
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Oxytocin can bias people to favor their own group
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at the expense of other groups.
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And in some cases, oxytocin can even decrease cooperation.
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So based on these studies, I could say oxytocin
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is an immoral molecule, and call myself Dr. Strangelove.
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(Laughter)
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So we've seen neuro-flapdoodle all over the headlines.
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We see it in supermarkets, on book covers.
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What about the clinic?
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SPECT imaging is a brain-scanning technology
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that uses a radioactive tracer
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to track blood flow in the brain.
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For the bargain price of a few thousand dollars,
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there are clinics in the U.S. that will give you
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one of these SPECT scans and use the image
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to help diagnose your problems.
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These scans, the clinics say, can help
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prevent Alzheimer's disease,
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solve weight and addiction issues,
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overcome marital conflicts,
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and treat, of course, a variety of mental illnesses
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ranging from depression to anxiety to ADHD.
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This sounds great. A lot of people agree.
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Some of these clinics are pulling in tens of millions
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of dollars a year in business.
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There's just one problem.
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The broad consensus in neuroscience
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is that we can't yet diagnose mental illness
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from a single brain scan.
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But these clinics have treated
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tens of thousands of patients to date,
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many of them children,
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and SPECT imaging involves a radioactive injection,
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so exposing people to radiation, potentially harmful.
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I am more excited than most people, as a neuroscientist,
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about the potential for neuroscience to treat mental illness
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and even maybe to make us better and smarter.
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And if one day we can say that cheese and chocolate
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help us make better decisions, count me in.
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But we're not there yet.
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We haven't found a "buy" button inside the brain,
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we can't tell whether someone is lying or in love
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just by looking at their brain scans,
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and we can't turn sinners into saints with hormones.
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Maybe someday we will, but until then,
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we have to be careful that we don't let overblown claims
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detract resources and attention away from the real science
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that's playing a much longer game.
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So here's where you come in.
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If someone tries to sell you something with a brain on it,
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don't just take them at their word.
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Ask the tough questions. Ask to see the evidence.
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Ask for the part of the story that's not being told.
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The answers shouldn't be simple, because the brain isn't simple.
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But that's not stopping us from trying to figure it out anyway.
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Thank you. (Applause)
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