Monkeys Prefer Gambling Risk To Sure Reward
DURHAM, N.C. -- Duke University Medical Center neurobiologists have pinpointed circuitry in the brains of monkeys that assesses the level of risk in a given action. Their findings -- gained from experiments in which they gave the monkeys a chance to gamble to receive juice rewards -- could give insights into why humans compulsively engage in risky behaviors, including gambling, unsafe sex, drug use and overeating.
The researchers, Michael Platt, Ph.D., and Allison McCoy, published their findings in the advanced online version of Nature Neuroscience, posted August 14, 2005. The research was sponsored by the National Institutes of Health, the EJLB Foundation, and the Klingenstein Foundation.
In their experiments, the researchers gave two male rhesus macaque monkeys chances to choose to look at either of two target lights on a screen. Looking at the "safe" target light yielded the same fruit juice reward each time. However, looking at the "risky" target light might yield a larger or smaller juice reward. The average juice reward delivered by looking at either target was the same.
To their surprise, the monkeys overwhelmingly preferred to gamble by looking at the risky target. This preference held, regardless of whether the scientists made the risky target reward more
variable, or whether the monkeys had received more or less fruit juice during the course of the day.
Next, we'll be teaching them how to be dealer for Texas Hold 'em . . .