The effect of somatosensory alpha transcranial alternating current stimulation on pain empathy is trait empathy and gender dependent

Abstract

Background: Pain empathy enables a person to experience and understand other's pain state by observing others in pain condition. Such prosocial ability is deficient in many psychopathological disorders. Somatosensory alpha suppression is considered as neural correlates of pain empathy and is hypothesized as a target for enhancement of pain empathy. Researches demonstrated that alpha suppression could be enhanced by transcranial alternating current stimulation (tACS) at alpha frequency non-invasively.

Aims: We applied alpha tACS over the primary somatosensory cortex of healthy subjects to investigate whether alpha tACS is able to enhance the pain empathy performance.

Results: The results showed that there was no difference of pain empathy performance between alpha tACS and sham tACS either when tACS was applied during the task or before task. While in the alpha tACS group, the pain empathy performance was positively correlated with empathic concern of male subjects, the sub-component of personal trait empathy.

Conclusions: Alpha tACS cannot alter the empathy performance overall, but the modulation effect of alpha tACS on pain empathy is dependent on the gender and trait empathy of subjects.

Keywords: Alpha ERD; empathy concern; pain empathy; transcranial alternating current stimulation.