The heart beats to reward: the effect of monetary incentive on heart rate.

Two experiments are reported which test the hypothesis that heart rate increases will be seen in response to monetary incentives during performance on a continuous motor task. In the first study, heart rate was significantly higher when subjects were paid 2o for each success feedback compared to subjects who received feedback only. In contrast, there was no effect of varying the probability of success (10% versus 90% success). Study 2 replicated the monetary incentive effect on heart rate, this time employing 100% success feedback. In neither study were subjects' response rates significantly affected by monetary incentive. In addition, control groups responding much faster on the task as a result of making it more predictable did not show increased heart rate. Consequently, these incentive effects are difficult to explain with a cardiac-somatic coupling interpretation. It was concluded that cardiac acceleration does occur in response to monetary incentives, even in the absence of failure feedback, and it was proposed that this incentive effect reflects the activation of an appetitive motivational system. Possible applications of the assessment of appetitive responses are suggested.