Decision making by rats: Delay versus amount of reward.

Abstract

Hungry rats were given sequences of free and forced trials in a 2-alley maze, food reward in 1 alley being a larger amount but at a longer delay than in the other alley. Different rats encountered different combinations of amount and delay and revealed reasonably consistent preferences in relation to the differential in reward. These data were used to estimate equivalent combinations that were fit by indifference functions and by equations describing the relative incentive value of different amounts and delays. In general, results support the possibility of a quantified theory of incentive motivation.