The task is simple: Upon seeing eight candy bars, choose your favorite. But instead of picking candy at Little Jo’s, undergraduates chose these bars in the lab of Paul Glimcher, a professor of neural science, economics and psychology at New York University, as part of an experiment exploring how people make choices.
Glimcher delivered the final lecture in the Rhode Island Medical Society’s bicentennial lecture series yesterday in Metcalf Auditorium.
Glimcher began his lecture by explaining his unique field. As Professor of Neuroscience David Sheinberg summarized in his introduction, Glimcher’s research is fundamentally about how the circuits of the brain allow people to make choices.
Glimcher calls his approach “neuroeconomics,” an “interdisciplinary fusion” of both approaches to understanding behavior. Economists, he said, look at decisions as products of the value, called utility, and the probabilities of different outcomes. But neuroscientists look at decisions as the product of the firing of individual brain cells called neurons.
He noted that there has been some skepticism of this approach — neuroscientists tend to question the value of economics, and economists debate the relevance of neuroscience, he said. But he said similar debates once occurred between chemists and biologists regarding the importance of knowing the structure of DNA, which is now recognized as a milestone in genetics.
Glimcher continued with an exploration of over 50 years of research about decision making. Following earlier work on reflexes in neuroscience and on utility in economic decisions theory, he co-authored a study that found a region of the brain that correlates to decisions, called the lateral intraparietal area. In the study, monkeys were presented two snacks. Lateral intraparietal neurons fired more frequently in the area representing the snack that the monkey wanted more. After the study was published in 1999, neuroscientists have devoted much attention to the area. Even “my dog has recorded in this cortical area,” Glimcher joked about the popularity of studying this region of the brain.
The findings also hold true in human subjects. Glimcher’s lab put undergraduates in an fMRI, a device that measures blood flow in the brain, and showed them different rewards, from a DVD of the movie “Madagascar” to a poster of a Monet painting. Activation in the lateral intraparietal area correlated with how the subjects eventually ranked the rewards, but only moderately, which he attributed to the noisiness of the fMRI signal.
Glimcher is currently working on a related-decision problem called the paradox of choice. When a monkey has to compare two similarly-ranked rewards and a third, less-desirable one, the third object hinders its ability to rank the other two. Similarly, when presented with eight candy bars at once, undergraduates have trouble picking their favorite even if they had valued them individually only moments before.
As Glimcher noted, the standard economic decision models do not predict this behavior. “The economics of the next 30 years will be one that takes advantage of all we’ve learned about how things are maximized, but respects the neurobiology” of the price of that maximization, he concluded.