Gender differences in the mu rhythm during empathy for pain: An electroencephalographic study

Our recent magnetoencephalography study demonstrated that the mu rhythm can reliably indicate sensorimotor resonance during the perception of pain in others (Cheng, Y., Yang, C.Y., Lin, C.P., Lee, P.L., Decety, J., 2008b. The perception of pain in others suppresses somatosensory oscillations: a magnetoencephalography study. NeuroImage 40, 1833-1840). The current study further investigated the neurophysiological mechanism underpinning empathy for pain in relation with gender through the measurements of the electroencephalographic mu suppression in healthy female (N = 16) and male (N = 16) adults during the observation of body parts in painful or no-painful situations. The results demonstrate that both genders exhibited sensorimotor activation related to pain empathy. However, females showed stronger mu suppressions than males when watching the painful as well as the non-painful situations. Further, the mu suppression for pain empathy was positively correlated with the scoring on the personal distress subscale of the interpersonal reactivity index only in the female participants. The present findings suggest the existence of a gender difference in pain empathy in relation with the sensorimotor cortex resonance. The mu rhythm can be a potential biomarker of empathic mimicry.