Sensitivity to temporal reward structure in amygdala neurons

Abstract

The temporal structure of reward occurrence has a fundamental influence on behavioral reinforcement and decision processes. However, we know very little about the underlying neuronal mechanisms. In this experiment, visual stimuli predicted different temporal reward structures that resulted in specific instantaneous probabilities of reward occurrence. Neurons in the amygdala, a major component of the brain's reward system, showed anticipatory activity preceding reward whose time courses reflected the different instantaneous reward probabilities. Furthermore, the magnitudes of amygdala responses to reward delivery covaried with the instantaneous probabilities. These data reveal sophisticated, time dependent reward signals in the amygdala and characterize further the important function of this brain region in reward processing.