Making the right choices in the face of uncertain outcomes is a critical skill in life, but to do that, the brain must have a way to evaluate the risks. Neurons in a part of the brain called the posterior cingulate cortex represent the riskiness of choices in monkeys, reports a paper in the September issue of Nature Neuroscience.
Faced with a choice between a reward that was guaranteed and an uncertain reward (a 50:50 chance of a reward that was smaller or larger than the guaranteed one), monkeys in this study typically chose to gamble. Indeed, the more risky the experimenters made the reward, the more likely the monkeys were to choose it, even when the probability of obtaining a larger reward from the risky target was reduced so that the risky choice led to a smaller average reward.
During the task, the authors recorded from neurons in the posterior cingulate cortex, and found that many of them responded more strongly to riskier targets. The authors suggest that these neurons may represent the subjective value of the choice to the monkey, rather than the absolute value of the reward.
Michael Platt (Duke University Medical Center, Durham, NC, USA)
Additional contact for comment on paper:
Daeyeol Lee (University of Rochester, NY, USA)
Abstract available online.
(C) Nature Neuroscience press release.
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