A new study published in Neuron this week lends support to the idea that gambling addictions may well have biological roots. Researchers at the Massachusetts General Hospital found that prize money could activate many of the same "reward" areas in the brain turned on by food and drugs. "This work argues that we can begin to dissect the systems that process reward and organize behavior in humans," says lead author Hans Breiter. "This is also the first demonstration that a monetary reward in a gambling-like experiment produces brain activation very similar to that observed in a cocaine addict receiving an infusion of cocaine."

The researchers set up an experiment to measure the brain activity of volunteers as they gambled. The subjects were given $50 and told they could lose it all or keep their potential winnings. Each subject played the game with one of three spinners: a "good spinner" offered them the chance to earn $10, $2.50 or nothing; an intermediate spinner offered $2.50, $0 or -$1.50; and a "bad spinner" let them win nothing or lose $1.50 or $6. The researchers measured each subject's brain activity using high-field functional magnetic resonance imaging (fMRI) both during six-second spins and after the results were in.

The scientists found that depending on whether a subject played the game with the good, intermediate or bad spinner, he or she showed strong, moderate or low activation levels in certain key brain regions. "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," Breiter says. "This similarity suggests that common brain circuitry is used for various types of rewards."