Measuring and modeling the interaction among reward size, delay to reward, and satiation level on motivation in monkeys.

ABSTRACT: Motivation is usually inferred from the likelihood or the intensity with which behavior is carried out. It is sensitive to external factors (e.g., the identity, amount, and timing of a rewarding outcome) and internal factors (e.g., hunger or thirst). We trained macaque monkeys to perform a nonchoice instrumental task (a sequential red-green color discrimination) while manipulating two external factors: reward size and delay-to-reward. We also inferred the state of one internal factor, level of satiation, by monitoring the accumulated reward. A visual cue indicated the forthcoming reward size and delay-to-reward in each trial. The fraction of trials completed correctly by the monkeys increased linearly with reward size and was hyperbolically discounted by delay-to-reward duration, relations

SUBMITTER: Minamimoto T 

PROVIDER: S-EPMC2637024 | biostudies-literature | 2009 Jan

REPOSITORIES: biostudies-literature