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How We Think

Brain Researchers Are Using MRIs to Predict Our Decisions Before They Are Made. The Results Are Intriguing, and a Little Disturbing.

May 02, 2004|Michael D'Antonio | Michael D'Antonio last wrote for the magazine about an Oregon town that honored a man who as a child had been warehoused in school for the retarded and was a subject in a government experiment.

What humans possess, jokes economist Colin Camerer, "is basically a monkey brain with a good publicist." That's his conclusion from observing the results of experiments by scientists at Caltech and elsewhere, who are peering into the human brain to see how we think--and finding they can predict the decisions their subjects will make.

Scans made at an MRI (magnetic resonance imaging) lab would typically be used to map an injury or diagnose disease. But here in Pasadena, the images help scientists understand the role that emotion plays in our economic choices.

As they unravel the decision-making process, the researchers are adding to our basic knowledge about human nature. Beyond this pure science, they also are shedding light on some of the mysteries of the marketplace. Their work could aid companies that want to appeal to our emotions, as well as consumers who want to better understand and possibly control their impulses.

Here's how the Caltech research works: Camerer recruits two people to play an investment game. One player is given $10 to invest and makes all investment decisions. The other player decides how the two players split the earnings. The game lasts 10 rounds--10 sets of investments, 10 choices about dividing the money. But there is one hitch. The investor can stop investing at any moment if upset at how the money is being divided.

"If you think unemotionally, you will realize that even if someone offers you $1, that's still $1 more than you had when the game started," Camerer says. "If they won't budge, then you should just take it and be ahead by $1. But some people refuse to do that. They would rather kill the whole deal than accept something they think is unfair."

As the players make their choices, the MRI machines register the activity in their brains. Researchers at Caltech, along with others at Princeton and Baylor universities using similar games, have discovered that the choices we make when we should use cold reason are heavily influenced by the brain's emotional centers. This is especially true when players call off the deal, giving up a chance at money just to spite a greedy negotiator.

The brain images displayed on video screens often predict a decision before players push their buttons. When the MRI shows lots of activity in the prefrontal cortex, where the logical resolution of a problem would register, Camerer expects both players will leave with cash. But when he sees more action in the anterior insula--home to disgust, nausea and similar sensations--he knows the negotiation will fail.

"Basically the brain toggles between 'Yes, money is good' and 'Ugh, this guy is treating me like crap.' Things will go back and forth as the brain asks, 'What should we do? What should we do?' If the amount of activity we see builds in the insula, then you know where it's going to go. They are going to shut the whole thing off." He estimates that researchers predict the outcome 70% of the time.

Camerer's quirky MRI studies are part of a new branch of science that is adding hard data to the study of decision-making and consumer behavior. Teams of economists, physicists, philosophers and physicians are discovering that even in situations when we need to be coolly detached, we are not as rational as we might hope. They are also redefining the roles played by those not-so-primitive parts of the human brain responsible for animal instinct and self-preservation.

"The publicist is the higher brain, which we use to make what we do seem like it makes sense, both to ourselves and other people." In truth, he adds, we often rely on our emotional, primitive "lower brain" to guide through difficult decisions. In other situations people make "gut" choices that work out well.

This discovery refutes long-standing assumptions, especially about how people behave in settings such as the stock market. "A lot of traditional economists would say that feelings are the tip of the iceberg, but rational thought is what lies below, determining your choice," Camerer explains. "Neuroscience would say that the huge part of the iceberg is the feeling."

In the future, our important practical and moral choices could be improved by our understanding of the brain's workings. The more we know about our monkey brains, the more likely we are to control them. But at the same time, we may be subjected to more powerful and insidious manipulation by merchandisers and propagandists who seek better ways to bypass our rational minds and appeal more directly to our primal fears and desires.

The first rule of life is basic survival. Roughly 100,000 years ago, human beings learned that banding together could provide far better security and comfort than an individual could find alone. According to prevailing theory, this social organization was so important that people developed intense emotional desires for belonging and for fairness in relationships.

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