Physiological and psychological responses induced by expressing empathy with others

To assess the physical and mental burdens associated with expressing empathy with another person's stress.

Nine female subjects listened to their partner's negative emotions aroused by a stress task (Stroop color-word test) under two conditions. In the first, the subject reacted empathetically to their partner ("with empathy"); in the second, the subject offered no response (control). Electroencephalograms and skin temperature of the second finger were recorded during the test. Subjective stress was estimated using a visual analog scale, whereas the level of cognition was expressed on a five-point ranking. Responses during and after expressions of empathy were examined by comparisons with control or by correlation.

Sympathetic nerve tone increased under both conditions (i.e. the skin temperature of the second finger fell). Subjective stress was not recognized by the subject while listening "with empathy", although it did increase significantly after the subject has listened "with empathy". Subjective stress was not felt under the control conditions. Right temporal activity while listening showed a significantly positive correlation with the level of cognition of feeling the same emotion as the stressed partner, whereas bilateral frontal activity after listening was significantly negative correlated with the level of cognition of understanding the emotions of the stressed partner.

Expressing empathy with another person's negative emotion led to increased physiological activity and subjective stress. Physiological responses to empathy depended on cognition of the different subjective factors. Cognition of sharing negative emotions activated the right temporal region of the brain, whereas cognition of understanding negative emotions inhibited bilateral frontal activities.