Negative and positive incentive contrast in humans with males vs females, monetary reinforcement, and reaction time

Abstract

Negative incentive contrast effects which were obtained for male human subjects by a reduction in the quantity of monetary incentives in a simple reaction time task failed to appear in female subjects. In a second experiment, male human subjects displayed positive contrast effects after an upshift in reward magnitude, while females failed to exhibit positive incentive contrast effects. While it appears that sex is a determiner of human incentive contrast effects, the present studies increased the generality of the observation of incentive contrast (1) from infrahumans to humans, and (2) from mental multiplication tasks with nonmonetary reinforcement to a reaction time task with monetary reinforcement.