You are currently viewing the abstract.
View Full TextLog in to view the full text
AAAS login provides access to Science for AAAS members, and access to other journals in the Science family to users who have purchased individual subscriptions.
Register for free to read this article
As a service to the community, this article is available for free. Existing users log in.
More options
Download and print this article for your personal scholarly, research, and educational use.
Buy a single issue of Science for just $15 USD.
Decisive Monkeys
Decision-making is a central theme in current research in cognitive neuroscience. Behavioral protocols have provided an entry into explorations of the neural processes that underlie decision-making. Empirical studies have provided support for a diffusion model in which information accumulates over time until a threshold is reached, with noisiness in the inputs related to decision errors. Kiani and Shadlen (p. 759) developed a behavioral task to study choice certainty and identified the corresponding neuronal representations in monkeys. The monkeys were allowed to choose to opt out of an uncertain, higher reward choice in favor of a certain, lower payoff. The same neurons that encoded the information used to make a choice also encoded the extent of certainty, which in humans would be described as the degree of confidence in one's decision.
Abstract
The degree of confidence in a decision provides a graded and probabilistic assessment of expected outcome. Although neural mechanisms of perceptual decisions have been studied extensively in primates, little is known about the mechanisms underlying choice certainty. We have shown that the same neurons that represent formation of a decision encode certainty about the decision. Rhesus monkeys made decisions about the direction of moving random dots, spanning a range of difficulties. They were rewarded for correct decisions. On some trials, after viewing the stimulus, the monkeys could opt out of the direction decision for a small but certain reward. Monkeys exercised this option in a manner that revealed their degree of certainty. Neurons in parietal cortex represented formation of the direction decision and the degree of certainty underlying the decision to opt out.
