Pathological gambling may have less to do with the thrill of winning than with the downer of losing, reports Vanderbilt University neuroscientist David Zald. He tested nine subjects under three sets of rules. In the primary scenario, a gambling simulation, a person was asked to pick one of four cards and told he would get a dollar if he picked the right one. Meanwhile, Zald monitored levels of dopamine—a euphoria-inducing brain chemical that influences motivation—in the subject’s brain. As expected, dopamine increased when the person won. “But we also saw something there that’s never been documented,” Zald says. “Dopamine actually decreased whenever a person didn’t receive the dollar.”
The gloom associated with losing might be the trigger that causes some people to latch onto gambling or other types of compulsive behaviors, Zald speculates. Rather than getting more of a high when they win, they might get more low when they don’t, making them more driven to correct the deficit. “And if you start with low dopamine,” Zald says, “the high of winning feels that much better.”
