The role of rewards in the survival and well-being of biological agents ranges from the control of vegetative functions to the organization of voluntary, goal-directed behavior. The brain extracts the reward information from a large variety of stimuli and events for appropriate use in the control of behavior. Recent studies revealed that neurons in a limited number of brain structures carry specific signals about past and future rewards. The neurophysiological study of reward processing within the framework of goal-directed behavior may contribute to a basic understanding of mechanisms of drug abuse and could thus have a strong medical and social impact. This article concerns the reward signals in the striatum and describes how its neurons detect rewards, learn to predict future rewards from past experience, and use reward information for learning, choosing, preparing and executing goal-directed behavior.

Behavioral Functions of Rewards

Biological agents need to acquire...