May 25, 2001

Researchers at the MGH and two other institutions have found that discrete parts of the human brain respond in an ordered fashion to the anticipation and reward of money. The study, published in this week's Neuron, demonstrates the first linkage of human brain events to ideas from behavioral economics. The research reveals that monetary rewards tap into a generalized system in the human brain that also processes other categories of reward, such as drugs and food.

"This research argues that we can begin to dissect the systems that process reward and organize behavior in humans," says lead author Hans Breiter, MD, co-director of the Motivation and Emotion Neuroscience Center in MGH Radiology. "This also is the first demonstration that a monetary reward in a gambling-like experiment produces brain activation similar to that observed in an addict receiving an infusion of cocaine." In other words, he says, the results give credence to the theory that gambling behavior may be similar to drug addiction.

The study was conducted by MGH scientists in collaboration with colleagues at Concordia University in Montreal and Princeton University in New Jersey.

Studying the brains of volunteers who participated in a game of chance, researchers monitored brain activity through a neuroimaging process called high-field functional magnetic resonance imaging (fMRI). The volunteers were given $50 and were told that they might lose some orall of it, retain it or increase it. They were shown a sequence of spinners that were divided into three sectors,each with a different monetary value.

These spinners included good spinners ($10, $2.50, $0), intermediate spinners ($2.50, $0, -$1.50), or bad spinners ($0, -$1.50, -$6). While the subjects watched each spinner in action, the researchers measured brain signals during the anticipation state (before the spinner stopped) and during the outcome phase (after the spinner stopped).

The brain images showed that the subjects demonstrated high, medium and low signals from some brain regions that mirrored the observation of the good, intermediate and bad spinners. "The results showed that an incentive unique to humans – money – produced patterns of brain activity that closely resembled patterns seen previously in response to other types of rewards. This similarity suggests that common brain circuitry is used for various types of rewards," notes Breiter.

One implication of this study is that scientists may be able to use brain scans in the future to measure what people like and dislike. Further research may help scientists understand the development of impulse disorders such as drug abuse and compulsive gambling.