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Where Your Brain Figures Out What It Doesn't Know

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Where Your Brain Figures Out What It Doesn't Know

Where Your Brain Figures Out What It Doesn't Know

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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From NPR News, this is ALL THINGS CONSIDERED. I'm David Greene.


And I'm Melissa Block.

Someone asks you a question. You may think you know the answer, but is your confidence justified? Well, according to new research, that depends on a bit of brain tissue right behind your eyes. This area seems to help us assess the reliability of our own mental functions.

And as NPR's Jon Hamilton reports, it works better in some people than in others.

JON HAMILTON: Knowing what you know, and what you don't, can keep you from making a fool of yourself.

Steve Fleming, a neuroscientist at University College London, says it can also help you win money.

Mr. STEVE FLEMING (Neuroscientist, University College London): Say, for instance, if you're on a game show, you might have the opportunity to ask the audience or phone a friend, for instance. You need to know how sure you are about your own answer before you opt to use those lifelines.

HAMILTON: Especially when there's a million bucks at stake. That was the situation for John Carpenter in 1999, when he appeared on "Who Wants to be a Millionaire?"

(Soundbite of TV show, "Who Wants to be a Millionaire?")

Mr. REGIS PHILBIN (Host, "Who Wants to be a Millionaire?"): Let's go for the million.

(Soundbite of applause)

HAMILTON: To win his million dollars, he had to answer this question.

(Soundbite of TV show, "Who Wants to be a Millionaire?")

Mr. PHILBIN: Which of these U.S. presidents appeared on the television series "Laugh-In"? Lyndon Johnson, Richard Nixon, Jimmy Carter, Gerald Ford?

HAMILTON: At first, Carpenter seems uncertain.

(Soundbite of TV show, "Who Wants to be a Millionaire?")


(Soundbite of laughter)

Mr. CARPENTER: I'd like to call my parents right now.

HAMILTON: But when he actually gets his father on the phone, his tone changes.

(Soundbite of TV show, "Who Wants to be a Millionaire?")

Mr. CARPENTER: I don't really need your help. I just wanted to let you know that I'm going to win the million dollars.

(Soundbite of laughter and applause)

HAMILTON: Carpenter knew he knew the answer.

(Soundbite of TV show, "Laugh-In")

President RICHARD NIXON: Sock it to me?

(Soundbite of laughter)

HAMILTON: Richard Nixon.

Fleming says that for years, scientists have been trying to figure out what's going on in our brains as we assess how confident we are in our knowledge and decisions.

So he and a group of researchers had 32 volunteers play a computer game. It's a bit like "Who Wants to be a Millionaire?" but without the big money.

Participants had to identify a patch of screen that was just slightly brighter than the rest of the screen. And every time they did this, they had to say how confident they felt about their choice.

Then the researchers scanned the brain of every participant. And Fleming says they found something.

Mr. FLEMING: We isolated a region of the prefrontal cortex, which is right at the front of the brain and is thought to be involved in high-level thought, conscious planning, monitoring of our ongoing brain activity.

HAMILTON: In people who were good at assessing their own level of certainty, that region had more gray matter and more connections to other parts of the brain.

Professor JANET METCALFE (Psychology, Columbia University): I thought it was a really interesting study.

HAMILTON: Janet Metcalfe is a psychology professor at Columbia University who studies how people know what they know. She says this self-monitoring process is essential for navigating the world. Am I sure that person's expression is friendly? Do I really know the route to the train station? And understanding what could go wrong, she says, could help people with problems like schizophrenia or Alzheimer's.

Prof. METCALFE: For example, there are elderly patients who are becoming demented. And some of them know that this is happening, and some of them don't. So if we're going to help those people, it's really important to know what the brain correlates are.

HAMILTON: Metcalfe says the study could also help scientists figure out why some people with healthy brains do such a bad job judging their own mental abilities.

She says people are especially bad at judging their own skill at reading another person's emotions.

Prof. METCALFE: In fact, there was one study where people who are narcissistic would say they were really, spectacularly good at this, and they were actually worse than everyone else.

HAMILTON: Metcalfe says there may be some good news, though, for people who want to get better at knowing what they know. She says there are hints that people can improve with practice. The new research appears in the journal Science.

Jon Hamilton, NPR News.

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