Transcranial direct current stimulation of the dorsolateral prefrontal cortex increased pain empathy.

Empathy for pain, a widely studied sub-form of empathy, is an ability to recognize and share the pain of others. It involves brain regions associated with the emotional component of pain. Recent studies found that emotional pain could be modulated by stimulating the dorsolateral prefrontal cortex (DLPFC) with transcranial direct current stimulation (tDCS). We hypothesized that tDCS of the DLPFC could modulate empathy for pain as well. In the present study, healthy subjects were asked to watch pictures depicting somebody under painful or non-painful conditions and to evaluate the pain intensity of others as well as their own pain-related unpleasantness before and after tDCS of the DLPFC. It was found that ratings for others' pain increased in subjects with an anodal tDCS of the DLPFC in comparison to those with sham tDCS, indicating enhanced pain empathy with the anodal tDCS. Furthermore, the changes of ratings for others' pain were positively correlated with the changes of pain-related self-unpleasantness. These findings indicate that tDCS could modulate pain empathy and be used as a potential tool for modulating diseases accompanied with empathy deficits.