Caltech Scientists Find First Physiological Evidence of Brain's Response to Inequality

Brain images during money-transfer experiments show "rich" participants prefer to see others get financial windfall

PASADENA, Calif.—The human brain is a big believer in equality—and a team of scientists from the California Institute of Technology (Caltech) and Trinity College in Dublin, Ireland, has become the first to gather the images to prove it.

Specifically, the team found that the reward centers in the human brain respond more strongly when a poor person receives a financial reward than when a rich person does. The surprising thing? This activity pattern holds true even if the brain being looked at is in the rich person's head, rather than the poor person's.

These conclusions, and the functional magnetic resonance imaging (fMRI) studies that led to them, are described in the February 25 issue of the journal Nature.

"This is the latest picture in our gallery of human nature," says Colin Camerer, the Robert Kirby Professor of Behavioral Economics at Caltech and one of the paper's coauthors. "It's an exciting area of research; we now have so many tools with which to study how the brain is reacting."

It's long been known that we humans don't like inequality, especially when it comes to money. Tell two people working the same job that their salaries are different, and there's going to be trouble, notes John O'Doherty, professor of psychology at Caltech, Thomas N. Mitchell Professor of Cognitive Neuroscience at the Trinity College Institute of Neuroscience, and the principal investigator on the Nature paper. 

But what was unknown was just how hardwired that dislike really is. "In this study, we're starting to get an idea of where this inequality aversion comes from," he says. "It's not just the application of a social rule or convention; there's really something about the basic processing of rewards in the brain that reflects these considerations."

The brain processes "rewards"—things like food, money, and even pleasant music, which create positive responses in the body—in areas such as the ventromedial prefrontal cortex (VMPFC) and ventral striatum.

In a series of experiments, former Caltech postdoctoral scholar Elizabeth Tricomi (now an assistant professor of psychology at Rutgers University)—along with O'Doherty, Camerer, and Antonio Rangel, associate professor of economics at Caltech—watched how the VMPFC and ventral striatum reacted in 40 volunteers who were presented with a series of potential money-transfer scenarios while lying in an fMRI machine.

For instance, a participant might be told that he could be given $50 while another person could be given $20; in a second scenario, the student might have a potential gain of only $5 and the other person, $50. The fMRI images allowed the researchers to see how each volunteer's brain responded to each proposed money allocation.

But there was a twist. Before the imaging began, each participant in a pair was randomly assigned to one of two conditions: One participant was given what the researchers called "a large monetary endowment" ($50) at the beginning of the experiment; the other participant started from scratch, with no money in his or her pocket.

As it turned out, the way the volunteers—or, to be more precise, the reward centers in the volunteers' brains—reacted to the various scenarios depended strongly upon whether they started the experiment with a financial advantage over their peers.

"People who started out poor had a stronger brain reaction to things that gave them money, and essentially no reaction to money going to another person," Camerer says. "By itself, that wasn't too surprising."

What was surprising was the other side of the coin. "In the experiment, people who started out rich had a stronger reaction to other people getting money than to themselves getting money," Camerer explains. "In other words, their brains liked it when others got money more than they liked it when they themselves got money."

"We now know that these areas are not just self-interested," adds O'Doherty. "They don't exclusively respond to the rewards that one gets as an individual, but also respond to the prospect of other individuals obtaining a reward."

What was especially interesting about the finding, he says, is that the brain responds "very differently to rewards obtained by others under conditions of disadvantageous inequality versus advantageous inequality. It shows that the basic reward structures in the human brain are sensitive to even subtle differences in social context."

This, O'Doherty notes, is somewhat contrary to the prevailing views about human nature. "As a psychologist and cognitive neuroscientist who works on reward and motivation, I very much view the brain as a device designed to maximize one's own self interest," says O'Doherty. "The fact that these basic brain structures appear to be so readily modulated in response to rewards obtained by others highlights the idea that even the basic reward structures in the human brain are not purely self-oriented."

Camerer, too, found the results thought provoking. "We economists have a widespread view that most people are basically self-interested, and won't try to help other people," he says. "But if that were true, you wouldn't see these sort of reactions to other people getting money."

Still, he says, it's likely that the reactions of the "rich" participants were at least partly motivated by self-interest—or a reduction of their own discomfort. "We think that, for the people who start out rich, seeing another person get money reduces their guilt over having more than the others."

Having watched the brain react to inequality, O'Doherty says, the next step is to "try to understand how these changes in valuation actually translate into changes in behavior. For example, the person who finds out they're being paid less than someone else for doing the same job might end up working less hard and being less motivated as a consequence. It will be interesting to try to understand the brain mechanisms that underlie such changes."

The research described in the Nature paper, "Neural evidence for inequality-averse social preferences," was supported by grants from the National Science Foundation, the Human Frontier Science Program, the Gordon and Betty Moore Foundation, and the Caltech Brain Imaging Center.


Caltech Neuroscientists Find Brain System Behind General Intelligence

Finding opens the door for more studies on biology of intelligence

PASADENA, Calif.—A collaborative team of neuroscientists at the California Institute of Technology (Caltech), the University of Iowa, the University of Southern California (USC), and the Autonomous University of Madrid have mapped the brain structures that affect general intelligence. 

The study, published the week of February 22 in the early edition of the Proceedings of the National Academy of Sciences, adds new insight to a highly controversial question: What is intelligence, and how can we measure it? 

The research team included Jan Gläscher, first author on the paper and a postdoctoral fellow at Caltech, and Ralph Adolphs, the Bren Professor of Psychology and Neuroscience and professor of biology. The Caltech scientists teamed up with researchers at the University of Iowa and USC to examine a uniquely large data set of 241 brain-lesion patients who all had taken IQ tests. The researchers mapped the location of each patient's lesion in their brains, and correlated that with each patient's IQ score to produce a map of the brain regions that influence intelligence. 

"General intelligence, often referred to as Spearman's g-factor, has been a highly contentious concept," says Adolphs. "But the basic idea underlying it is undisputed: on average, people's scores across many different kinds of tests are correlated. Some people just get generally high scores, whereas others get generally low scores. So it is an obvious next question to ask whether such a general ability might depend on specific brain regions."

The researchers found that, rather than residing in a single structure, general intelligence is determined by a network of regions across both sides of the brain. 

"One of the main findings that really struck us was that there was a distributed system here. Several brain regions, and the connections between them, were what was most important to general intelligence," explains Gläscher. 

"It might have turned out that general intelligence doesn't depend on specific brain areas at all, and just has to do with how the whole brain functions," adds Adolphs. "But that's not what we found. In fact, the particular regions and connections we found are quite in line with an existing theory about intelligence called the 'parieto-frontal integration theory.' It says that general intelligence depends on the brain's ability to integrate—to pull together—several different kinds of processing, such as working memory." 

The researchers say the findings will open the door to further investigations about how the brain, intelligence, and environment all interact.

Other coauthors on the paper, "The distributed neural system for general intelligence revealed by lesion mapping," are David Rudrauf and Daniel Tranel of the University of Iowa; Roberto Colom of the Autonomous University of Madrid; Lynn Paul of Caltech; and Hanna Damasio of USC. The work at Caltech was funded by the National Institutes of Health, the Simons Foundation, the Deutsche Akademie der Naturforscher Leopoldina, and a Global Center of Excellence grant from the Japanese government.


Caltech Neuroscientists Discover Brain Area Responsible for Fear of Losing Money

Finding offers neuroscientists insight into economic behavior

PASADENA, Calif.—Neuroscientists at the California Institute of Technology (Caltech) and their colleagues have tied the human aversion to losing money to a specific structure in the brain—the amygdala.

The finding, described in the latest online issue of the journal Proceedings of the National Academy of Sciences (PNAS), offers insight into economic behavior, and also into the role of the brain's amygdalae, two almond-shaped clusters of tissue located in the medial temporal lobes. The amygdala registers rapid emotional reactions and is implicated in depression, anxiety, and autism.

The research team responsible for these findings consists of Benedetto de Martino, a Caltech visiting researcher from University College London and first author on the study, along with Caltech scientists Colin Camerer, the Robert Kirby Professor of Behavioral Economics, and Ralph Adolphs, the Bren Professor of Psychology and Neuroscience and professor of biology. 

The study involved an examination of two patients whose amygdalae had been destroyed due to a very rare genetic disease; those patients, along with individuals without amygdala damage, volunteered to participate in a simple experimental economics task.

In the task, the subjects were asked whether or not they were willing to accept a variety of monetary gambles, each with a different possible gain or loss. For example, participants were asked whether they would take a gamble in which there was an equal probability they'd win $20 or lose $5 (a risk most people will choose to accept) and if they would take a 50/50 gamble to win $20 or lose $20 (a risk most people will not choose to accept). They were also asked if they'd take a 50/50 gamble on winning $20 or losing $15—a risk most people will reject, "even though the net expected outcome is positive," Adolphs says.

Both of the amygdala-damaged patients took risky gambles much more often than subjects of the same age and education who had no amygdala damage. In fact, the first group showed no aversion to monetary loss whatsoever, in sharp contrast to the control subjects.

"Monetary-loss aversion has been studied in behavioral economics for some time, but this is the first time that patients have been reported who lack it entirely," says de Martino.

"We think this shows that the amygdala is critical for triggering a sense of caution toward making gambles in which you might lose," explains Camerer. This function of the amygdala, he says, may be similar to its role in fear and anxiety.

"Loss aversion has been observed in many economics studies, from monkeys trading tokens for food to people on high-stakes game shows," he adds, "but this is the first clear evidence of a special brain structure that is responsible for fear of such losses."

The work in the paper, titled "Amygdala damage eliminates monetary loss aversion," was supported by the Gordon and Betty Moore Foundation, the Human Frontier Science Program, the Wellcome Trust, the National Institutes of Health, the Simons Foundation, and a Global Center of Excellence grant from the Japanese government.

Kathy Svitil

Caltech Scientists Develop Novel Use of Neurotechnology to Solve Classic Social Problem

Research shows how brain imaging can be used to create new and improved solutions to the public-goods provision problem

PASADENA, Calif.—Economists and neuroscientists from the California Institute of Technology (Caltech) have shown that they can use information obtained through functional magnetic resonance imaging (fMRI) measurements of whole-brain activity to create feasible, efficient, and fair solutions to one of the stickiest dilemmas in economics, the public goods free-rider problem—long thought to be unsolvable.

This is one of the first-ever applications of neurotechnology to real-life economic problems, the researchers note. "We have shown that by applying tools from neuroscience to the public-goods problem, we can get solutions that are significantly better than those that can be obtained without brain data," says Antonio Rangel, associate professor of economics at Caltech and the paper's principal investigator.

The paper describing their work was published today in the online edition of the journal Science, called Science Express.

Examples of public goods range from healthcare, education, and national defense to the weight room or heated pool that your condominium board decides to purchase. But how does the government or your condo board decide which public goods to spend its limited resources on? And how do these powers decide the best way to share the costs?

"In order to make the decision optimally and fairly," says Rangel, "a group needs to know how much everybody is willing to pay for the public good. This information is needed to know if the public good should be purchased and, in an ideal arrangement, how to split the costs in a fair way."

In such an ideal arrangement, someone who swims every day should be willing to pay more for a pool than someone who hardly ever swims. Likewise, someone who has kids in public school should have more of her taxes put toward education.

But providing public goods optimally and fairly is difficult, Rangel notes, because the group leadership doesn't have the necessary information. And when people are asked how much they value a particular public good—with that value measured in terms of how many of their own tax dollars, for instance, they’d be willing to put into it—their tendency is to lowball.

Why? “People can enjoy the good even if they don’t pay for it,” explains Rangel. "Underreporting its value to you will have a small effect on the final decision by the group on whether to buy the good, but it can have a large effect on how much you pay for it."

In other words, he says, “There’s an incentive for you to lie about how much the good is worth to you.”

That incentive to lie is at the heart of the free-rider problem, a fundamental quandary in economics, political science, law, and sociology. It's a problem that professionals in these fields have long assumed has no solution that is both efficient and fair.

In fact, for decades it's been assumed that there is no way to give people an incentive to be honest about the value they place on public goods while maintaining the fairness of the arrangement.

“But this result assumed that the group's leadership does not have direct information about people's valuations,” says Rangel. “That's something that neurotechnology has now made feasible.”

And so Rangel, along with Caltech graduate student Ian Krajbich and their colleagues, set out to apply neurotechnology to the public-goods problem.

In their series of experiments, the scientists tried to determine whether functional magnetic resonance imaging (fMRI) could allow them to construct informative measures of the value a person assigns to one or another public good. Once they’d determined that fMRI images—analyzed using pattern-classification techniques—can confer at least some information (albeit "noisy" and imprecise) about what a person values, they went on to test whether that information could help them solve the free-rider problem.

They did this by setting up a classic economic experiment, in which subjects would be rewarded (paid) based on the values they were assigned for an abstract public good.

As part of this experiment, volunteers were divided up into groups. “The entire group had to decide whether or not to spend their money purchasing a good from us,” Rangel explains. “The good would cost a fixed amount of money to the group, but everybody would have a different benefit from it.”

The subjects were asked to reveal how much they valued the good. The twist? Their brains were being imaged via fMRI as they made their decision. If there was a match between their decision and the value detected by the fMRI, they paid a lower tax than if there was a mismatch. It was, therefore, in all subjects' best interest to reveal how they truly valued a good; by doing so, they would on average pay a lower tax than if they lied.

“The rules of the experiment are such that if you tell the truth,” notes Krajbich, who is the first author on the Science paper, “your expected tax will never exceed your benefit from the good.”

In fact, the more cooperative subjects are when undergoing this entirely voluntary scanning procedure, “the more accurate the signal is,” Krajbich says. “And that means the less likely they are to pay an inappropriate tax.”

This changes the whole free-rider scenario, notes Rangel. “Now, given what we can do with the fMRI,” he says, “everybody’s best strategy in assigning value to a public good is to tell the truth, regardless of what you think everyone else in the group is doing.”

And tell the truth they did—98 percent of the time, once the rules of the game had been established and participants realized what would happen if they lied. In this experiment, there is no free ride, and thus no free-rider problem.

“If I know something about your values, I can give you an incentive to be truthful by penalizing you when I think you are lying,” says Rangel.

While the readings do give the researchers insight into the value subjects might assign to a particular public good, thus allowing them to know when those subjects are being dishonest about the amount they'd be willing to pay toward that good, Krajbich emphasizes that this is not actually a lie-detector test.

“It’s not about detecting lies,” he says. “It’s about detecting values—and then comparing them to what the subjects say their values are.”

“It’s a socially desirable arrangement,” adds Rangel. “No one is hurt by it, and we give people an incentive to cooperate with it and reveal the truth.”

“There is mind reading going on here that can be put to good use,” he says. “In the end, you get a good produced that has a high value for you.”

From a scientific point of view, says Rangel, these experiments break new ground. “This is a powerful proof of concept of this technology; it shows that this is feasible and that it could have significant social gains.”

And this is only the beginning. “The application of neural technologies to these sorts of problems can generate a quantum leap improvement in the solutions we can bring to them,” he says.

Indeed, Rangel says, it is possible to imagine a future in which, instead of a vote on a proposition to fund a new highway, this technology is used to scan a random sample of the people who would benefit from the highway to see whether it's really worth the investment. "It would be an interesting alternative way to decide where to spend the government's money," he notes.

In addition to Rangel and Krajbich, other authors on the Science paper, “Using neural measures of economic value to solve the public goods free-rider problem,” include Caltech's Colin Camerer, the Robert Kirby Professor of Behavioral Economics, and John Ledyard, the Allen and Lenabelle Davis Professor of Economics and Social Sciences. Their work was funded by grants from the National Science Foundation, the Gordon and Betty Moore Foundation, and the Human Frontier Science Program.

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Lori Oliwenstein

Caltech Neuroscientists Find Brain Region Responsible for Our Sense of Personal Space

Finding could offer insight into autism and other disorders

Pasadena, Calif.—In a finding that sheds new light on the neural mechanisms involved in social behavior, neuroscientists at the California Institute of Technology (Caltech) have pinpointed the brain structure responsible for our sense of personal space.

The discovery, described in the August 30 issue of the journal Nature Neuroscience, could offer insight into autism and other disorders where social distance is an issue.

The structure, the amygdala—a pair of almond-shaped regions located in the medial temporal lobes—was previously known to process strong negative emotions, such as anger and fear, and is considered the seat of emotion in the brain. However, it had never been linked rigorously to real-life human social interaction.

The scientists, led by Ralph Adolphs, Bren Professor of Psychology and Neuroscience and professor of biology and postdoctoral scholar Daniel P. Kennedy, were able to make this link with the help of a unique patient, a 42-year-old woman known as SM, who has extensive damage to the amygdala on both sides of her brain.

"SM is unique, because she is one of only a handful of individuals in the world with such a clear bilateral lesion of the amygdala, which gives us an opportunity to study the role of the amygdala in humans," says Kennedy, the lead author of the new report.

SM has difficulty recognizing fear in the faces of others, and in judging the trustworthiness of someone, two consequences of amygdala lesions that Adolphs and colleagues published in prior studies.

During his years of studying her, Adolphs also noticed that the very outgoing SM is almost too friendly, to the point of "violating" what others might perceive as their own personal space. "She is extremely friendly, and she wants to approach people more than normal. It's something that immediately becomes apparent as you interact with her,” says Kennedy.

Previous studies of humans never had revealed an association between the amygdala and personal space. From their knowledge of the literature, however, the researchers knew that monkeys with amygdala lesions preferred to stay in closer proximity to other monkeys and humans than did healthy monkeys.

Intrigued by SM's unusual social behavior, Adolphs, Kennedy, and their colleagues devised a simple experiment to quantify and compare her sense of personal space with that of healthy volunteers.

The experiment used what is known as the stop-distance technique. Briefly, the subject (SM or one of 20 other volunteers, representing a cross-section of ages, ethnicities, educations, and genders) stands a predetermined distance from an experimenter, then walks toward the experimenter and stops at the point where they feel most comfortable. The chin-to-chin distance between the subject and the experimenter is determined with a digital laser measurer.

Among the 20 other subjects, the average preferred distance was .64 meters—roughly two feet. SM's preferred distance was just .34 meters, or about one foot. Unlike other subjects, who reported feelings of discomfort when the experimenter went closer than their preferred distance, there was no point at which SM became uncomfortable; even nose-to-nose, she was at ease. Furthermore, her preferred distance didn't change based on who the experimenter was and how well she knew them.

"Respecting someone's space is a critical aspect of human social interaction, and something we do automatically and effortlessly," Kennedy says. "These findings suggest that the amygdala, because it is necessary for the strong feelings of discomfort that help to repel people from one another, plays a central role in this process. They also help to expand our understanding of the role of the amygdala in real-world social interactions."

Adolphs and colleagues then used a functional magnetic resonance imaging (fMRI) scanner to examine the activation of the amygdala in a separate group of healthy subjects who were told when an experimenter was either in close proximity or far away from them. When in the fMRI scanner, subjects could not see, feel, or hear the experimenter; nevertheless, their amygdalae lit up when they believed the experimenter to be close by. No activity was detected when subjects thought the experimenter was on the other side of the room.

"It was just the idea of another person being there, or not, that triggered the amygdala," Kennedy says. The study shows, he says, that "the amygdala is involved in regulating social distance, independent of the specific sensory cues that are typically present when someone is standing close, like sounds, sights, and smells."

The researchers believe that interpersonal distance is not something we consciously think about, although, unlike SM, we become acutely aware when our space is violated. Kennedy recounts his own experience with having his personal space violated during a wedding: "I felt really uncomfortable, and almost fell over a chair while backing up to get some space. 

Across cultures, accepted interpersonal distances can vary dramatically, with individuals who live in cultures where space is at a premium (say, China or Japan) seemingly tolerant of much closer distances than individuals in, say, the United States. (Meanwhile, our preferred personal distance can vary depending on our situation, making us far more willing to accept less space in a crowded subway car than we would be at the office.)

One explanation for this variation, Kennedy says, is that cultural preferences and experiences affect the brain over time and how it responds in particular situations. "If you're in a culture where standing close to someone is the norm, you'd learn that was acceptable and your personal space would vary accordingly," he says. "Even then, if you violate the accepted cultural distance, it will make people uncomfortable, and the amygdala will drive that feeling."

The findings may have relevance to studies of autism, a complex neurodevelopmental disorder that affects an individual's ability to interact socially and communicate with others. "We are really interested in looking at personal space in people with autism, especially given findings of amygdala dysfunction in autism. We know that some people with autism do have problems with personal space and have to be taught what it is and why it’s important," Kennedy says.

He also adds a word of caution: "It's clear that amygdala dysfunction cannot account for all the social impairments in autism, but likely contributes to some of them and is definitely something that needs to be studied further."

Other coauthors of the paper, "Personal Space Regulation by the Human Amygdala," are postdoctoral scholar Jan Gläscher and J. Michael Tyszka, the associate director of the Caltech Brain Imaging Center and director of Magnetic Resonance Physics. The work was funded by the National Institute of Mental Health, the Simons Foundation, the Della Martin Foundation, and a global Center of Excellence grant from Japan.

Kathy Svitil

Caltech Researchers Pinpoint the Mechanisms of Self-Control in the Brain

Study of dieters shows how two brain areas interact in people with the willpower to say no to unhealthy foods

PASADENA, Calif.--When you're on a diet, deciding to skip your favorite calorie-laden foods and eat something healthier takes a whole lot of self-control--an ability that seems to come easier to some of us than others. Now, scientists from the California Institute of Technology (Caltech) have uncovered differences in the brains of people who are able to exercise self-control versus those who find it almost impossible.

The key? While everyone uses the same single area of the brain to make these sorts of value-laden decisions, a second brain region modulates the activity of the first region in people with good self-control, allowing them to weigh more abstract factors--healthiness, for example--in addition to basic desires such as taste to make a better overall choice.

These findings, which are being published in the May 1 issue of the journal Science, not only provide insight into the interplay between self-control and decisionmaking in dieters, but may explain how we make any number of decisions that require some degree of willpower.

"A very basic question in economics, psychology, and even religion, is why some people can exercise self-control but others cannot," notes Antonio Rangel, a Caltech associate professor of economics and the paper's principal investigator. "From the perspective of modern neuroscience, the question becomes, 'What is special about the circuitry of brains that can exercise good behavioral self-control?' This paper studies this question in the context of dieting decisions and provides an important insight."

That insight was the result of an innovative experiment: A group of volunteers--all self-reported dieters--were shown photos of 50 foods, including everything from Snickers bars to Jello to cauliflower. The participants were asked to rate each of the foods based on how good they thought that food would taste. Afterwards, they were shown the same slides again and asked to rate each of the foods based on its supposed health benefits.

From those ratings, the researchers selected an "index food" for each volunteer--a food that fell about in the middle of the pack in terms of tastiness and supposed health benefits.

The participant was then shown the 50 items one final time and was asked to choose between it and the index item. (To keep the choosers "honest" without forcing them to eat 50 different foods in one sitting, the researchers would randomly select a number corresponding to one of the slides, and the participant would have to eat whichever food had been chosen at that point.)

All three viewings of the slides were done with the participant inside an MRI scanner, so that the blood-oxygen level dependent signal (a proxy for neuronal activity) in specific areas of the brain could be measured.

After all the choices had been made, the researchers were able to pick out 19 volunteers who showed a significant amount of dietary self-control in their choices, picking mostly healthy foods, regardless of taste. They were also able to identify 18 additional volunteers who showed very little self-control, picking what they believed to be the tastier food most of the time, regardless of its nutritional value.

When they looked at the brain scans of the participants, they found significant differences in the brain activity of the self-control group as compared to the non-self-controllers.

Previous studies have shown that value-based decisions--like what kind of food to eat--are reflected in the activity of a region in the brain called the ventromedial prefrontal cortex, or vmPFC. If activity in the vmPFC goes down, explains Todd Hare, a postdoctoral scholar in neuroeconomics and the first author on the Science paper, "it means the person is probably going to say no to that item; if it goes up, they're likely to choose that item."

In the non-self-controllers, Rangel notes, the vmPFC seemed to only take the taste of the food into consideration in making a decision. "In the case of good self-controllers, however, another area of the brain--called the dorsolateral prefrontal cortex [DLPFC]--becomes active, and modulates the basic value signals so that the self-controllers can also incorporate health considerations into their decisions," he explains. In other words, the DLPFC allows the vmPFC to weigh both taste and health benefits at the same time.

"The vmPFC works during every decision," says Hare. "The DLPFC, on the other hand, is more active when you're employing self-control."

"This, ultimately, is one reason why self-controllers can make better choices," Rangel adds.

Still, the DLPFC can only do so much. For instance, it can't override a truly negative reaction to a food, notes Hare. "We rarely got people to say they'd eat cauliflower if they didn't like cauliflower," he says. "But they would choose not to eat ice cream or candy bars, knowing they could eat the healthier index food instead."

"After centuries of debate in social sciences we are finally making big strides in understanding self-control from watching the brain resist temptation directly," says Colin Camerer, the Robert Kirby Professor of Behavioral Economics in Caltech's Division of Humanities and Social Sciences and another of the paper's coauthors. "This study, and many more to come, will eventually lead to much better theories about how self-control develops and how it works for different kinds of temptations."

The next step, the researchers say, is to come up with ways to engage the DLPFC in the decisions made by people with poor self-control under normal conditions. For instance, Hare says, it might be possible to kick the DLPFC into gear by making the health qualities of foods more salient for people, rather than asking them to make the effort to judge a food's health benefits on their own. "If we highlight the fact that ice cream is unhealthy just before we offer it," he notes, "maybe we can reduce its value in advance, give the person a head start to making a better decision."

Whether this is indeed feasible remains to be tested. But clearly, the possibilities are tantalizing, since these same sorts of value-based choices are at the root of everything from addictions like smoking to risky financial decisions.

"Imagine how much better life could be if we knew how to flex the willpower muscles in the brain and strengthen them with exercises," says Camerer.

The work described in the Science paper, "Self-Control in Decision-Making Involves Modulation of the vmPFC Valuation System," was funded by the Moore Foundation and the Economic Research Service of the U.S. Department of Agriculture on Behavioral Health Economics Research on Dietary Choice and Obesity. 

Lori Oliwenstein

Mapping Intelligence in the Brain

PASADENA, Calif.-- Neuroscientists at the California Institute of Technology (Caltech) have conducted the most comprehensive brain mapping to date of the cognitive abilities measured by the Wechsler Adult Intelligence Scale (WAIS), the most widely used intelligence test in the world. The results offer new insight into how the various factors that comprise an "intelligence quotient" (IQ) score depend on particular regions of the brain.

Neuroscientist Ralph Adolphs, Bren Professor of Psychology and Neuroscience and professor of biology at Caltech, Caltech postdoctoral scholar Jan Gläscher, and their colleagues compiled the maps using detailed magnetic resonance imaging (MRI) and computerized tomography (CT) brain scans of 241 neurological patients recruited from the University of Iowa's extensive brain-lesion registry.

All of the patients had some degree of cognitive impairment from events such as strokes, tumor resection, and traumatic brain injury, as assessed by testing using the WAIS. The WAIS test is composed of four indices of intelligence, each consisting of several subtests, which together produce a full-scale IQ score. The four indices are the verbal comprehension index, which represents the ability to understand and to produce speech and use language; the perceptual organization index, which involves visual and spatial processing, such as the ability to perceive complex figures; the working memory index, which represents the ability to hold information temporarily in mind (similar to short-term memory); and the processing speed index.

The researchers first transferred the brain scans of all 241 patients to a common reference frame, an approach pioneered by neuroscientist Hanna Damasio of the University of Southern California, a coauthor of the study. Using a technique called voxel-based symptom-lesion mapping (a voxel is the three-dimensional analog of a pixel, and represents a volume of about 1 cubic millimeter), Adolphs and his colleagues then correlated the location of brain injuries with scores on each of the four WAIS indices.

"The first question we asked was if there are any parts of the brain that are critically important for these indices or if they are very distributed, with intelligence processed globally in a way that can't be mapped," Adolphs says. With the exception of processing speed, which appears scattered throughout the brain, the lesion mapping showed that the other three cognitive indices really do depend on specific brain regions.

For example, lesions in the left frontal cortex were associated with lower scores on the verbal comprehension index; lesions in the left frontal and parietal cortex (located behind the frontal lobe) were associated with lower scores on the working memory index; and lesions in the right parietal cortex were associated with lower scores on the perceptual organization index.

Somewhat surprisingly, the study revealed a large amount of overlap in the brain regions responsible for verbal comprehension and working memory, which suggests that these two now-separate measures of cognitive ability may actually represent the same type of intelligence, at least as assessed using the WAIS.

The details about the structure of intelligence provided by the study could be useful in future revisions of the WAIS test so that its various subtests are grouped on the basis of neuroanatomical similarity rather than on behavior, as is the case now.

In addition, the brain maps produced by the study could be used as a diagnostic aid. Clinicians could combine the maps with their patients' Wechsler test results to help localize likely areas of brain damage. "It wouldn't be sufficient to be diagnostic, but it would provide information that clinicians could definitely use about what parts of the brain are dysfunctional," Adolphs says. 

The converse--using brain-scan results to predict the IQ of patients as measured by the Weschler test--may also be possible. Although the results wouldn't be as clear-cut as they are in patients with brain lesions, Adolphs says, "you could take a large sample of healthy brains and measure the relative volumes of specific brain areas and draw some associations with these IQ factors." 

The paper, "Lesion Mapping of Cognitive Abilities Linked to Intelligence," appears in the March 12 issue of Neuron. The work was supported in part by the Akademie der Naturforscher Leopoldina, the National Institutes of Health, and the Gordon and Betty Moore Foundation.


Kathy Svitil
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Markets Are Better Than Patents in Promoting Discovery, Says Caltech Economists

Winner-take-all patent system in need of an overhaul, researchers say

PASADENA, Calif.--When it comes to intellectual curiosity and creativity, a market economy in which inventors can buy and sell shares of the key components of their discoveries actually beats out the winner-takes-all world of patent rights as a motivating force, according to a California Institute of Technology (Caltech)-led team of researchers.

In a paper published in this week's issue of the journal Science, an international team of researchers led by Peter Bossaerts, the William D. Hacker Professor of Economics and Management and professor of finance at Caltech, and Swiss Finance Institute Professor at the Ecole Polytechnique Federale Lausane in Switzerland, describes a series of experiments designed to quantify the different ways patent systems and market forces might influence a person's drive to invent, to solve intellectual problems.

Over the last hundred-plus years, the patent system has been the gold standard by which we've protected and tried to incentivize intellectual discovery. But Bossaerts and his team--which includes Debrah Meloso from Bocconi University in Milan, Italy, and Jernej Copic from the University of California, Los Angeles--now say there's a new game in town. Or, rather, an old game--the same free-market forces that drive so much of our economy.

The problem with patents, Bossaerts explains, is that they "give the prize to the winner only. Whoever comes in second or third walks away empty." This means that, for the patent system to work well, "a large number of people need to think they're the absolute best." The economic theory that motivated patent regulation even assumes that all people have an equal chance of being the best, he adds.

In reality, Bossaerts says, that's not how people think. Very few of us think we're the person most likely to come up with a unique solution to a problem before anyone else--and so very few of us are likely to even try to solve a difficult problem. We just assume that someone else will beat us to the patent punch.

On the other hand, Bossaerts notes, studies have shown that more than 50 percent of people think they're better than the median--a statistical impossibility, but one that can be exploited in the marketplace to generate trade.

The researchers were able to provide concrete evidence for these ideas by running a series of experiments in which participants were asked to solve what is known as "the knapsack problem." In the knapsack problem, participants are given a large number of items to pack into a knapsack that cannot possibly hold all of the items; their job is to try to figure out how to maximize the number of "valuable" items they can fit into the knapsack.

"These aren't always the most expensive items," says Bossaerts. "For instance, if you're packing the knapsack to go on a trip, one of the items you would consider most valuable would probably be a toothbrush."

Participants in Bossaerts's knapsack experiment had to solve one set of problems under a regime that worked in much the same way as a traditional patent system, with a $66 reward for whoever figured out the solution first.

The second set of problems was to be solved in a kind of free-trading market regime. Each item that could go into the knapsack was given a different price, and each participant was given five securities per item at the beginning of the experiment. They were then encouraged to buy and sell their securities for the various items, stocking up on shares of items they believed were likely to be included in the problem's solution, and getting rid of shares of items they thought would be left out of the knapsack.

Once the solution was revealed, the securities of the left-behind items became worthless, while the participants who had bought up shares of the included items were allowed to keep their earnings of $1 a share. While nobody won the full $66 as in the patent groups, several people in the market groups were able to benefit financially from coming up with a workable solution to the problem.

That solution didn't even have to be the optimal one, Bossaerts notes. "They didn't have to fully solve the problem to benefit financially," he explains. "They could solve only part of the problem--figure out a few items they believed would be in the solution, or those they thought wouldn't be there--and focus buying and selling those."

This resulted in a large number of different people trying different ideas each time the game was played. Allowing people to benefit even if they only tackle a part of a problem might well lead to more collaboration, and to the faster development of a final solution to the whole problem, Bossaerts adds. "This is important, because the nature of knapsack problems is such that one can only be sure that the optimal solution has been found after one has tried everything," he says.

To 'win' in the patent group, on the other hand, required coming up with the right answer first, which seemed to remove the incentive for the large majority of participants to even attempt solving the problem. "In one example, there was a woman who won a couple of times in a row," Bossaerts recalls. "She had over $120, and everyone else had nothing. They just gave up trying, saying, 'Why bother? She'll just figure it out before us anyway.'"

How would these sorts of market forces work in the "real world"? Bossaerts uses the concept of scientists working to invent a fuel-cell catalyst.

"If a scientist is really convinced that platinum, for instance, is the best catalyst for his fuel cell, the best way to go, he would go out and buy a bunch of platinum futures, knowing that once his invention got into the public domain, the items that go into that invention--in this case, platinum--will go up in price."

Without a patent on the invention, other people would also be free to create platinum-based fuel cells. But there would still be a benefit to being the first: That inventor would be the one able to buy up platinum futures when the prices were at their lowest. "In the market system, if you're first, you still have the advantage," Bossaerts explains. "But you also give the second and third person a chance to profit from their work as well."

Bossaerts's next step is to try to collect data to explain why the market system works. "Our conjecture is that it's due to this idea of overconfidence, that most people think they are better than most other people. But this study wasn't able to test that idea specifically, so we're hoping to do that in future studies."

Bossaerts is well aware that his ideas--even with solid data to back them up--are controversial. People are very protective of their patents, and of the system that guards them, he says. But in reality, says Bossaerts, his team's findings should be seen as reassuring, rather than threatening.

"The take-home message from this study is that one should not be too nervous about protecting intellectual property," he explains. "There are other ways you can benefit from your efforts as well, as long as you have a functioning free market economy in place. Even if you get rid of most patent laws, people will still innovate."

The study described in this paper, "Promoting Intellectual Discovery: Patents vs. Markets," was funded in part by the U.S. National Science Foundation and the Swiss Finance Institute.

Lori Oliwenstein
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Caltech's Colin Camerer Makes a Game of Economic Theory

Lecture at AAAS meeting looks at role of cognitive psychology in developing economic strategies

"Economics is the field that has used game theory the most broadly to understand bargaining, pricing, firm competition, incentive contracts, and more," explains Camerer, who is the Robert Kirby Professor of Behavioral Economics in Caltech's Division of Humanities and Social Sciences. "Almost all the analysis, however, assumes people plan ahead and carefully figure out what others will do, which often results in mathematical claims that are highly unrealistic cognitively."

In reality, Camerer says, a key part of strategizing about what other people--or corporations, or countries--will do involves thinking about what they think you will do. "You can also think about what others think you think. . . . It can go on and on."

Research by Camerer and others--including Teck Ho at the University of California, Berkeley, and Kuan Chong from the National University of Singapore--into this form of strategizing has led to what Camerer calls the "cognitive hierarchy theory."

"The cognitive hierarchy theory finds that people only do a few steps of this kind of iterated thinking," he explains. "Usually, it's just one step: I act as if others are unpredictable. But sometimes it's two steps: I act as if others think *I* am unpredictable. You can think of the number of steps a person takes as their strategic IQ. A higher strategic IQ means you are outthinking a lot of other people."

Most of us have a pretty low strategic IQ, but that's to be expected, Camerer notes. To reach a truly high strategic IQ requires either special experience with a particular type of game (such as poker), training, or, in rare cases, special gifts.

The cognitive hierarchy theory has been tested using many different game-theory experiments, as well as field-data sets. One such data set, Camerer says, is the Swedish LUPI lottery in which everyone picks a number from one to 99,999, and the lowest unique positive integer wins. "In this game you want to pick a low number, but one that is also a number nobody else will think of," he notes.

With more than 2.5 million observations to analyze--as well as a laboratory recreation of the lottery using numbers 1 to 99--Camerer and his colleagues from Caltech, the Stockholm School of Economics, and the National Taiwan University say the results fit extremely well with the original theory. If people were accurately guessing what everyone else would do, they would pick numbers from 1 to 5000 with equal frequency, and rarely pick any higher numbers. The Swedish players, however, chose lower numbers--numbers below 1000--much too often, from a strategic point of view. "This pattern is consistent with people doing two to three steps of thinking," Camerer says.

Camerer and colleagues have also been looking at how people make economic decisions when they are not given sufficient information to make an informed choice. "What should you infer about a restaurant with an online menu that doesn't have prices?" he asks. If you guessed that their prices are high, you'd probably be right. "And yet," says Camerer, "there are a number of people who could conclude that leaving prices off doesn't mean anything."

Or take the example Camerer studies, along with Caltech PhD alumnus Alex Brown (now at Texas A&M University) and Dan Lovallo, from the University of Western Australia--that of movies released without first being shown to critics, a process known as a "cold opening." To test their theory Camerer and colleagues looked at all 850 widely-released movies in the U.S. from 2000 through 2006.

"Usually, the movies that are not shown in advance are below-average movies as ultimately rated by both critics and moviegoers," says Camerer. "But there is a 15 percent increase in box office revenue from not first showing the movie."

The reason for this boost in ticket sales? Camerer thinks it has to do with people who don't think strategically--who don't have high strategic IQs. "We think it means you can fool some of the people some of the time," he says. "Specifically, you can fool the people who don't pay attention to reviews and who also don't realize that not wanting to show a movie to critics is a bad sign."

Camerer notes that cognitive hierarchy theory can be used by people and businesses to forecast more accurately what other people are likely to do in various situations; they can then use those forecasts to make better choices. "For instance," he says, "the data about cold openings could be used by the movie industry to retrospectively forecast whether they should have held a movie back from the critics." It could also help them to decide what to do in future cases to maximize their profits.


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Lori Oliwenstein
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Caltech-Led Researchers Find Negative Cues from Appearance Alone Matter for Real Elections

PASADENA, Calif.-- Brain-imaging studies reveal that voting decisions are more associated with the brain's response to negative aspects of a politician's appearance than to positive ones, says a team of researchers from the California Institute of Technology (Caltech), Scripps College, Princeton University, and the University of Iowa. This appears to be particularly true when voters have little or no information about a politician aside from their physical appearance.

The research was published online in the journal Social Cognitive and Affective Neuroscience ( on October 28.

Deciding whom to trust, whom to fear, and indeed for whom to vote in an election depends, in part, on quick, implicit judgments about people's faces. Although this general finding has been scientifically documented, the detailed mechanisms have remained obscure. To probe how a politician's appearance might influence voting decisions, Michael Spezio, an assistant professor of psychology at Scripps College and visiting associate at Caltech, and Antonio Rangel, an associate professor of economics at Caltech, examined brain activation in subjects looking at the faces of real politicians.

Using a functional magnetic resonance imaging (fMRI) scanner at the Caltech Brain Imaging Center, the researchers obtained high-resolution images of brain activation as volunteers made decisions about politicians based solely on their pictures.

The researchers conducted two independent studies using different groups of volunteers viewing the images of different politicians. Volunteers were shown pairs of photos, each with a politician coupled with their opponent in a real election in 2002, 2004, or 2006. Importantly, none of the study subjects were familiar with the politicians whose images they viewed.

In some experiments, the volunteers had to make character-trait judgments about the politicians--for example, which of the two politicians in the pair looked more competent to hold congressional office, or which looked more likely to physically threaten the volunteer. In other experiments, volunteers were asked to cast their vote for one politician in the pair; once again, their decisions were based only on the politicians' appearances.

The results correlated with actual election outcomes. For example, politicians who were thought to look the most physically threatening in the experiment were more likely to have actually lost their elections in real life. The correlation held true even when volunteers saw the politicians' pictures for less than one tenth of a second.

Importantly, the pictures of politicians who lost elections, both in the lab and in the real world, were associated with greater activation in key brain areas known to be important for processing emotion. This was true when volunteers simply voted and also when they closely examined the politicians' pictures for character traits. The studies suggest that negative evaluations based only on a politician's appearance have some effect on real election outcomes--and, specifically, may influence which candidate will lose an election. This influence appears to be more uniform than the influence exerted by positive evaluations based on appearance.

This finding fits with prior studies in cognitive neuroscience as well as in political theory.

"The results from our two studies suggest that intangibles like a candidate's appearance may work preferentially, or more uniformly, via negative motives, and by means of brain processing contributing to such negative evaluations," says Michael Spezio, the lead author on the study.

"It's important to note that the brain region most closely associated with seeing pictures of election losers, known as the insula, is known to be important in processing both negative and positive emotional evaluations. Its increased activation in response to the appearance of election losers is consistent with its association with negative emotional evaluations in several domains, including the sight of someone who looks disgusted or untrustworthy," Spezio says.

"Candidates try to evoke emotional reactions when they campaign for office, and this research gives us a new perspective on how much emotions might matter, and how they might matter, in terms of how voters view candidates," says study coauthor R. Michael Alvarez, a professor of political science at Caltech and codirector of the Caltech/MIT Voting Technology Project.

One surprise in the study is that negative evaluations, such as the perception that a candidate is threatening, influence election loss significantly more than positive evaluations like attractiveness influence election success. "While these findings are certainly very provocative, it is important to note their limitations," says study senior author Ralph Adolphs, Bren Professor of Psychology and Neuroscience and professor of biology at Caltech, and director of the Caltech Brain Imaging Center.

In particular, Adolphs says, the observed effects, while statistically significant, were rather small. "There is no doubt that many, many sources of information come into play when we make important and complex decisions, such as will happen in the upcoming elections. We are not claiming that how the candidates look is all there is to the story of how voters make up their minds--or that this is even the biggest part of the story. However, we do think it has some effect--and, moreover, that this effect may be largest when voters know little else about a candidate."

Adds Spezio, "Given the size of the effects we see, we are likely detecting the influence of voters who have little or no information about a candidate's views or life story, for example, or who choose not to pay attention to that information. Our finding is consistent with literature showing that humans prioritize negative information about outgroups"--groups of individuals who are perceived to not belong to one's own group, as defined by characteristics such as profession, age, gender, social community, and shared values, but to an outside group. "A voter who knows nothing about a candidate will likely put that candidate into a default outgroup position. From there, negative attributions are expected to get the primary weight in decisionmaking. And that is precisely what we see," he says.

"Earlier behavioral studies showed that rapid, effortless inferences from facial appearance predict the outcomes of political elections," says study coauthor Alex Todorov, an assistant professor of psychology and public affairs at Princeton University. In 2005, Todorov published the first study to show that voter decisions are significantly associated with character-trait judgments that are based entirely on the visual appearance of political candidates.

"However," Todorov adds, "these studies did not show how these inferential processes could play out at the level of individual voters. Two types of evidence will be critical to delineate the causal effects of appearance on electoral success: work by political scientists studying real voting decisions and work by cognitive neuroscientists studying the proximal mechanisms of the effects of inferences on decisions. The fMRI studies are an important step in the latter direction."

The coauthors of the study, titled, "A neural basis for the effect of candidate appearance on election outcomes," are John O'Doherty, associate professor of psychology at Caltech, Kyle Mattes of the University of Iowa, and Hackjin Kim of Korea University.

The work was supported by the Gordon and Betty Moore Foundation, the National Science Foundation, and the National Institutes of Health.



Kathy Svitil
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