Pain and Gain: Monetary Incentive Moderates Pain’s Impact on Effort-Related Cardiac Response

Two experiments tested the combined effect of pain and monetary incentive on effort-related cardiovascular response during cognitive performance. Healthy volunteers received individually adjusted painful or nonpainful thermal stimulations during a difficult cognitive task and expected high or low monetary incentive for successful performance. Our primary cardiovascular effort measure were responses of cardiac pre-ejection period (PEP) during task performance. Based on the pain literature suggesting that pain adds supplementary demand in cognitive functioning, we predicted pain to increase subjective task difficulty. Moreover, based on motivational intensity theory, we expected this to increase effort only when high effort was justified by high monetary incentive. Correspondingly, we predicted pain to lead to low effort due to disengagement when monetary incentive was low. Effort in the nonpainful conditions was expected to fall in between these conditions. The results of both studies offered support to our predictions. Our findings provide the first evidence for the moderating effect of monetary incentive on physical pain’s impact on effort. This suggests that motivational incentives can counteract effort deficits associated with pain. Clinical implications are discussed.