Bad Wiring

In games of skill, a near miss can mean you’re improving. Not so with games of chance. At a slot machine, almost hitting the jackpot doesn’t increase your odds of cashing in with the next push of the button. Our brains, however, may not recognize the distinction.

For gamblers and nongamblers alike, the same region of the midbrain is activated by both near misses and jackpots, Henry W. Chase and Luke Clark report in The Journal of Neuroscience (May 5). The strength of the near-miss response in the brain correlates with the degree of gambling addiction—that is, problem gamblers exhibit a stronger response to near misses than casual gamblers do. The researchers speculate that the neurotransmitter dopamine gives gamblers a jolt of pleasure when they come close to winning. So they keep playing. And hoping.