Jonah Lehrer: Passions Of The Brain
TERRY GROSS, host:
From WHYY in Philadelphia, I'm Terry Gross with FRESH AIR.
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GROSS: When science journalist Jonah Lehrer found himself paralyzed by indecision in the supermarket aisle, unable to make up his mind about which flavor of Cheerios to buy, he knew it was time to write a book about the neuroscience of decision-making. On today's FRESH AIR, we'll talk about his new book, "How We Decide." It's an investigation into how the human mind makes decisions.
Also we talk with Iranian-American comic Maz Jobrani. He formally toured with the Axis of Evil Comedy Tour. Now he's on a solo tour, where he makes a point of getting his mixed audiences of Arabs, whites, Asians, blacks, Muslims and Jews to laugh together at each other. That's all coming up on FRESH AIR.
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GROSS: This is FRESH AIR. I'm Terry Gross. I sometimes have a hard time making decisions, even unimportant ones, which is why I wanted to talk with Jonah Lehrer, the author of the new book, "How We Decide."
The book reports on what neuroscientists, with the help of brain imaging, are learning about how the human mind makes decisions. Jonah Lehrer is editor-at-large for Seed Magazine and the author of "Proust was a Neuroscientist." He edits the "Mind Matters" blog for Scientific American and writes his own blog, "The Frontal Cortex."
Jonah Lehrer, welcome to FRESH AIR. Now, you describe yourself as pathologically indecisive. I relate to that.
Mr. JONAH LEHRER (Author, "How We Decide"): Yes. Guilty as charged.
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GROSS: And so as an example, tell us about the decision you were struggling to make that led to this book, this really important decision?
Mr. LEHRER: The revelation occurred in the cereal aisle of the supermarket. I was sent to the supermarket with what seemed like simple instructions, which was buy a box of Cheerios. And it wasn't until I got the supermarket that I realized that there were 20 different kinds of Cheerios. There were original Cheerios. There were honey-nut Cheerios, apple-cinnamon, multigrain, the yogurt-with-the-berry thing, and then of course there are all the generic varieties of Cheerios.
And so I found myself spending literally a half an hour, 30 minutes, in the cereal aisle of the supermarket, trying to choose between boxes of Cheerios. And that's when I realized I had a problem, and I became really curious as to what was actually happening inside my head while I was struggling to make a decision.
GROSS: Now, were you struggling to make this decision for your own breakfast or for somebody else's?
Mr. LEHRER: It was for my breakfast and my wife's breakfast. So it was clearly a very weighty decision. You know, I won't bore you by discussing how hard it is for me to choose floss and toothpaste.
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Mr. LEHRER: So this is something I struggle with every day. It's a classic case of paralysis by analysis.
GROSS: Which means what?
Mr. LEHRER: Which means I'm simply thinking too much in the supermarket. I come up with long lists of reasons to prefer honey-nut Cheerios, and then I look at the apple-cinnamon Cheerios, and then I come up with long lists of reasons to prefer apple-cinnamon Cheerios, and it goes on and on like that. I'm stuck in this loop of self-consciousness where I come up with reason after reason after reason.
And so it was really that very basic, everyday failure that really first got me interested in the subject of decision-making.
GROSS: Now, one of the things you learned for sure from writing your book is that sometimes too much information is a really bad thing when it comes to making a decision, and that's part of the predicament you were in. You had all these different brands, and they each have a certain, like, topping and a certain amount of sugar, and…
Mr. LEHRER: And there's price. I mean there are so many variables to consider.
GROSS: Right, right, yeah. So is that - was that part of your problem in the supermarket aisle, and why is too much information so paralyzing?
Mr. LEHRER: Yeah, that was definitely, I think, a big part of my problem. And I think the reason too much information is paralyzing ultimately gets back to the brain and the way the brain is built and the fact that our prefrontal cortex, the part of the brain that's responsible for these kinds of deliberate, rational decisions - when we try to think through our breakfast options -that's a pretty feeble part of the brain.
It's kind of depressing to hear that, but it's actually a relatively limited and bounded part of the brain. It can only hold about seven pieces of information in the prefrontal cortex at any given moment.
So when you try to think through, even a decision as banal as choosing a breakfast cereal, you can very quickly overwhelm your prefrontal cortex.
GROSS: Wow. Now let me just ask you, before we get to other things that you report on in your book, if you were making that decision in that same supermarket aisle now, knowing what you know now about the brain and decision-making, how would you do it differently?
Mr. LEHRER: I still take a little too long in the cereal aisle, to be perfectly honest. But now what I try to do is I try to honestly pay attention to what I refer to in the book as the emotional brain, that part of my brain that has a better understanding of what I actually want to eat for breakfast.
So I try to really pay close attention to that, and you know, and eavesdrop on my, you know, on my own brain and try not to pay so much attention to the reasons I'm generating, on the fly, and actually listen closer to my feelings.
GROSS: You write in your book, though, you know, we're supposed to be rational creatures. Plato wrote about how we're rational creatures, and we should be making rational decisions, but you learned that that's not exactly how decision-making works, that there's a lot of emotional parts of the brain that come into play when making an intelligent decision. Can you talk a little bit about that part of the brain and how it helps inform decision-making?
Mr. LEHRER: Well, Plato had this great metaphor for the mind, which was that there's this rational charioteer, and it's his job to oversee these emotional horses who tend to run wild, and you know, this is - you know, reason's in the seat, reason's in the driver's seat, and we make the best decisions when we trust the rational charioteer.
I think most scientists would modify that metaphor a bit and say, well, it's not quite a, you know, rider with reigns on horses. It's more like a rider trying to control an elephant, and the elephant is the emotional brain and we have much less control over what we actually do than we think we do.
It's sort of the illusion of rationality, where we're great at rationalizing decisions, but we're not quite so rational. And so what I refer to an emotional brain, and what scientists tend to refer to as the emotional brain or limbic system, is the collection of brain areas scattered throughout the cortex -includes the amygdala, the insula, the nucleus accumbens, the ventral striatum - brain areas that tend to traffic in Dopamine, and they generate all sorts of subtle feeling that drive our behavior, even when we're not aware of them.
And I think one of the best examples of this comes from the work of a neurologist named Antonio Demasio, who in the early 1980s was studying patients who, because of a brain tumor, lost the ability to experience their emotions. So they didn't feel the everyday feelings of fear and pleasure. And you'd think, if you were Plato, that these people would be philosopher-kings, that they would be perfectly rational creatures, they'd make the best set of decisions possible. And instead, what you find is that they are like me in the cereal aisle, that they're pathologically indecisive, that they would spend all day trying to figure out where to eat lunch.
They'd spend five hours choosing between a blue pen or a black pen or a red pen, that all these everyday decisions we take for granted, they couldn't make. And that's because they were missing these subtle, visceral signals that were telling them to just choose the black pen or to eat the tuna fish sandwich or whatever. And then when we're cut off from these emotional signals, the most basic decisions become all but impossible.
GROSS: Now brain imaging is being used to help scientists, help neurologists, understand the process of decision-making and which parts of the brain come into play when decisions are being made. Are there parts of the brain that the scientists are beginning to understand play a significant role in the decision-making process?
Mr. LEHRER: I think one thing that's surprised scientists, that's become visible in brain scanners, is what's sometimes referred to as the vulcanization of the brain. The fact that there are - at any given moment, there's a tremendous argument happening inside your cortex, that it's not simply one brain area that reacts to one thing. That you know, for example, choosing what to buy activates this emotional tug of war inside your head. That some brain areas respond to the pleasure of getting something new, of buying that new red sweater, and other brain areas react to the pain of having to spend money.
And you know, so this decision that seems like such a simple, easy decision, that when you look under the surface of the brain, there's actually this tug of war taking place, this argument taking place.
So I think that's one thing that brain scanners really allowed us to see, that decisions often result from this argument happening inside the head.
GROSS: And is there a part of the brain that's responsible for integrating all the different information that you're getting from the different parts of your brain - the part of the brain that wants to buy the sweater, the part of your brain that thinks you're spending too much, the part of your brain that thinks maybe it doesn't look that good on me anyways?
Mr. LEHRER: In the case of that shopping example, and this is a general truism, it seems to be the prefrontal cortex. It seems to be different parts of the frontal lobes, like the orbital frontal cortex, that are responsible for integrating these emotions, and you know, and helping you integrate them into your decision-making, you know, into what you actually choose to buy.
But I think one crucial thing to do in decision-making is not to force a settlement onto the argument. I think what we too often do is we tend to shut off different brain areas and kind of impose certainty from the top down, and I think that's a bad thing, that it's sometimes disquieting for us to have these emotional arguments taking place inside our head, to not know if we should actually buy the red sweater.
And so I think what we too often do is turn off brain areas and ignore brain areas that are trying to tell us something. That you know, these feelings coming from the unconscious, percolating up from below, they're signals that are trying to tell us something. And I think too often, we shut them off and ignore them just because we actually really want to buy the red sweater.
GROSS: My guest is science journalist Jonah Lehrer. His new book is called "How We Decide." We'll talk more after our break. This is FRESH AIR.
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GROSS: If you're just joining us, my guest is science writer Jonah Lehrer, and we're talking about his new book, "How We Decide," which is basically about the neurology of decision-making.
One of the things you write about in your book is Dopamine, and many of us know that Dopamine is a neurotransmitter that's related to Parkinson's Disease. But you're not writing about Parkinson's, and you're not even writing about Dopamine in terms of movement, and the symptom associated with a lack of Dopamine in Parkinson's Disease is an inability to move or a twitching.
So where does Dopamine come into play in the process of decision-making?
Mr. LEHRER: It comes into play a lot. It's one of the crucial neurotransmitters behind decision-making. I talk about Dopamine. I think Dopamine is often associated with Parkinson's and is also associated with stuff like sex, drugs and rock 'n' roll. You know, it's the neurotransmitter responsible for all those feelings we probably shouldn't indulge. It gets tossed around a lot when people talk about stuff like cocaine and sex.
But Dopamine's even more important than that. It also seems to modulate many of our feelings, from the pleasure of eating chocolate cake or a crack high to feelings of fear and disgust.
So it, in many respects, is one of the key neurotransmitters of emotion in general. And I think when you talk about decision-making, that's part of what makes it so important. And I think there's also been a lot of really interesting work, much of it done by a scientist named Wolfram Schultz at Cambridge University, that have shown how Dopamine neurons react in detail to the real world.
GROSS: Can you tell us about one of those studies?
Mr. LEHRER: His experiments observe a really elegant protocol. He'll monitor individual Dopamine neurons in the brain of a monkey, and he'll show that at first, the neurons respond to a reward, to a squirt of juice.
So if you give the monkey a squirt of juice, these Dopamine neurons will fire, and the monkey experiences the pleasure of getting a squirt of apple juice. That's the reward. But these neurons quickly adapt to the pleasure. So they quickly stop firing.
That, you know, that makes perfect sense. You have an iPod. It makes you happy for a day or two, and then it stops, you know, giving you squirts of joy every time you look at the iPod. We adapt to these kind of hedonic pleasures.
But what Wolfram Schultz found is that if you then play a bell before giving the monkey a squirt of juice, the Dopamine neurons will fire whenever you play the bell. And if you flash a light before playing a bell before giving a squirt a juice, they'll fire whenever you flash a light, and if you play a song before flashing a light before ringing the bell, etcetera, etcetera, the Dopamine neurons will always try to predict the reward.
So they're called prediction neurons. Their job is to predict the first event that signals a reward is coming, a squirt of juice is coming. And so you can begin to understand how these neurons are so important in terms of allowing us to make sense of reality, in terms of finding the patterns and correlations and causations that allow us to actually figure out what's going to happen. And most importantly from the perspective of evolution, figure out when our squirts of juice are going to arrive - try to make sense of those rewards.
You know, and so you can begin to understand why they're so important for decision-making in terms of allowing us to make decisions that allow us to maximize our rewards.
GROSS: Another interesting study pertaining to Dopamine had to do with people who develop gambling addictions. Tell us about that one.
Mr. LEHRER: I talked to a woman named Ann Klinestiver, who she was diagnosed with Parkinson's in 1998, and she was put on, like many Parkinsonian patients, put on a drug called a Dopamine agonist. And the purpose of these drugs is to increase the amount of Dopamine in the brain to help compensate for the massive cell loss of Dopamine neurons in the back of the brain, the part of the brain that controls bodily movement.
One of the common side effects of these drugs is gambling compulsions. Some studies estimate that as many as 10 to 15 percent of patients on these drugs develop some sort of gambling problem. And in the case of Ann, it's a very sad story. It really ruined her life. She lost her entire life savings, more than $250,000. Her husband left her. It was a very traumatic experience. And you know, one of the saddest parts of the story to me is that it never occurred to her that it might be her medication that was doing this. She thought it was that she just all of a sudden discovered this thing she couldn't control.
As soon as she was taken off her Dopamine agonist in 2004, the compulsion disappeared within the week, and she was all of a sudden able to control her slot-machine habit. She had a compulsion for slot machines. She would spend 18 hours at a time putting quarters into one-armed bandits. And I think one of the reasons slot machines and games of chance in general are so addictive is because they hijack the Dopamine system.
The Dopamine system's great at finding patterns. It can find the pattern that predicts a squirt of juice, but it's terrible at dealing with random systems. It's terrible at dealing with that random-number generator inside the slot machine because it generates a consistently surprising reward.
So even though there's no pattern to find, we can't help but search for a pattern.
GROSS: So explain a little bit more why taking this Dopamine-related drug would turn somebody, would possibly turn somebody into a compulsive gambler.
Mr. LEHRER: Well because what it does is - the surviving Dopamine neurons in mid-brain, the part of your brain that seems to respond to those kinds of rewards in a casino, those kinds of rewards generated by, you know, the clanging coin of a slot machine when you actually get some money in return, those neurons were - became very saturated with neurotransmitters. So those Dopamine neurons simply had too much Dopamine.
So when Ann got a reward from a slot machine, when she got some coins in return, the end result was this surge of emotion, this surge of Dopamine that signaled something really good had happened. And so she became transfixed by this random system.
Her brain was literally trying to figure it out, in essence. It was trying to find the pattern that predicted the clanging coins, that predicted when she would win in the casino.
But the reality, of course, is that there's no pattern to be found. You know, that no matter how hard her Dopamine neurons tried, they would never find the sequence of events that predicted the payout. But because they were so saturated with neurotransmitter because she was on this Dopamine agonist drug, she simply couldn't walk away.
GROSS: You know, you point out that our brains weren't designed to deal with the amount of information that we're confronted with now and the number of choices that we're confronted with.
You say that some scientists think that we can deal with, say, four distinct variables at any one time, and others say maybe between five and nine. But still that's a pretty low number of variables, considering the difficult choices that we have to make now and the options that often present themselves, both in silly, trivial and important, profound decisions.
So do you recommend trying to block out some of those variables to make a decision possible?
Mr. LEHRER: You know, blocking out might not be the best option, but I think we should definitely be conscious of the fact that we have limited machines, that our brain isn't omnipotent and that it can only take in so much information at any one time.
One of the studies I talk about in the book concerns a study done by a Stanford psychologists who - they had two groups of people. One group they had memorize a two-digit number; the other group they had memorize a seven-digit number. Then they marched these two groups down the hall and gave them a choice between two snacks.
One snack was a rich, gooey slice of chocolate cake. The other snack was a responsible fruit salad. The people who memorized a two-digit number were twice as likely to choose the fruit salad as the people who memorized the seven-digit number, who were twice as likely to choose the chocolate cake. And the reason is that those extra five digits - doesn't seem like very much information at all, just five extra numbers - so overwhelmed the prefrontal cortex that there wasn't enough processing power leftover to exert self-control.
So that gives us a sense of just how limited in capacity our brain actually is and I think points to the fact that we should absolutely be aware of these limitations.
So that doesn't necessarily mean, you know, you have to block out information and never use Google. I think it just means that we should be aware of this and that if you've had a hard day at work or if you're trying to - you know, if you just spent all morning on a crossword puzzle, then be aware that your willpower's going to be a little bit weaker, that especially these rational faculties of the brain are very limited in capacity.
GROSS: You know, in addition to writing about science in books and for the Boston Globe, you have a blog and write about all kinds of interesting things on there. What has gotten the most reaction of everything that you've written about?
Mr. LEHRER: I think probably - this is probably a year ago - I wrote about a series of experiments involving wine. And I've since learned about this wonderful subculture on the Internet of wine aficionados. And this experiment concerned a experiment done by a scientist at the University of Bordeaux, and it was done on wine experts, people who were going to school to learn about wine. And he showed that basically you can trick these wine experts into believing all sorts of silly stuff, that you could give them a white wine that was dyed red, and they would describe this white wine in terms of, you know, they'd talk about its crushed red fruit and how it smelled like blackberries and full of tannins.
And you could give them a cheap wine, but if you served it in an expensive bottle, it would be called refined and elegant. And these basic findings wouldn't be surprising to a psychologist. We're doing this kind of stuff all the time. The brain is constantly warping its sensations to reflect our expectations. That in a sense we, you know, we see what we want to see and taste what we want to taste and disregard the rest. And yet somehow when you talk about it in terms of wine, people become very sensitive.
GROSS: You're very good at translating science, and I'm wondering how you got interested in science. I think a lot of people would probably complain that science isn't emphasized as much as they'd like in schools anymore. How did you realize that you loved science?
Mr. LEHRER: You know, I've always loved science, and I always thought I'd be a scientist. And I worked for several year in a really wonderful lab, the lab of Ayr Kendell(ph) at Columbia. I was just a technician, you know, the manual laborers of science. You make the gels, and you do the PCRs and stuff like that. And one of the things I learned from that was that I was a very bad scientist.
The post-doc I worked for, who remains a very close friend, used to joke that I excelled at experimental failure, that I found new ways to make his experiments not work.
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Mr. LEHRER: And I think that, you know, I realized that as much as I love science and the ideas of science, I didn't quite have the discipline. I didn't love the process. I didn't love the actual experimentation. I wasn't good at taking a very complex question and finding ways to parse it into very testable questions.
So that's when I first got interested in science writing and the idea of translating science. Because as much as I love the ideas of science, and most days, I still can't believe that someone lets me do this for a living - you know, just getting to talk to scientists is as good as it gets - I found that I wasn't good at the day-to-day science. And I think all great scientists really excel - they don't just love the ideas. They also love the manual labor of science.
GROSS: Jonah Lehrer, thanks so much for talking with us.
Mr. LEHRER: Thanks so much for having me.
GROSS: Jonah Lehrer is the author of "How We Decide." He writes the blog "The Frontal Cortex." I'm Terry Gross, and this is FRESH AIR.