Representation of Confidence Associated with a Decision by Neurons in the Parietal Cortex
Roozbeh Kiani and
Michael N. Shadlen
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.
E-mail: roozbeh{at}u.washington.edu (R. K.); shadlen{at}u.washington.edu (M.N.S.)
