Effects of cause of pain on the processing of pain in others: an ERP study.

Determining how the perceived cause of pain influences the perception of pain in others has implications for prosocial behavior and moral reasoning. In this research, behavior and event-related potential (ERP) responses were recorded as 28 participants (12 men, 16 women) viewed images of painful situations said to be self-inflicted by the protagonist or caused by another person on the protagonist. As predicted, participants provided significantly higher pain intensity ratings for depictions featuring pain caused by another person than depictions of self-inflicted pain. ERP analyses showed no significant differences between protagonist alone and protagonist with other images of pain in the early negative component (N1). However, contrary to initial hypotheses, more positive P3 amplitudes were induced by images of self-inflicted pain in protagonists than images of protagonist pain caused by another person. Salience was considered as a key influence that may help to account for this pattern of findings.