Sex differences in affective response to different intensity of emotionally negative stimuli: An event-related potentials study

• Sex differences in affective response are related to different emotional intensity.
• Both sexes showed affective response to highly and moderately negative stimuli at N2.
• Both sexes showed affective response to highly negative stimuli at LPP.
• Affective response to moderately negative stimuli at LPP was present only in females.

Previous studies have extensively reported an advantage of females in empathy as compared with males. It remains to be clarified, however, whether these sex differences are associated with sex specific neural processes underlying empathic response to different intensity of emotional stimulus. The present study examined sex differences in empathy for suffering persons by recording event-related potentials (ERP) to different emotional intensity. We compared affective response in males and females, who were exposed to a series of highly negative (HN), moderately negative (MN), and neutral pictures. The results revealed that both males and females showed a short-latency affective response, as indexed by frontal–central N2, to HN and MN stimuli. Moreover, both sexes showed a long-latency affective response, as indexed by central–parietal LPP, to HN stimuli. However, long-latency affective response to MN stimuli was present only in females, and sex differences were localized to the parietal sites. This suggests that the well-known female advantage in empathy may be attributable to the unique sensitivity of females to the affective state of persons in moderate suffering. Our results provide neuroscientific evidence for differences in affective response to different intensity of emotionally negative stimuli between the two sexes.