Control of movements and temporal discounting of reward.

Let us assume that the purpose of any movement is to position our body in a more rewarding state. People and other animals discount future reward as a function of time. Recent results suggest that there is a correlation between changes in this reward temporal discount function and changes in saccadic velocity and duration. These results suggest that each movement carries a cost because its duration delays acquisition of reward. The value that the brain assigns to the stimulus, and the rate at which it discounts this value in time, form a cost that appears to influence the motor commands that move our body.