Detection of the facial expression of emotion and self-report measures in empathic situations are influenced by sensorimotor circuit inhibition by low-frequency rTMS

BACKGROUND Empathic responses to facial cues are a main social competency. Both appraisal processes (facial emotion detection) and self-perceived empathy (empathic responsiveness) in response to emotional faces are thought to be related to empathic behavior, although no systematic analysis has been performed to assess their relationship. OBJECTIVES The current research explored the contribution of the frontal sensorimotor system to facial detection and self-reported empathic measures by using repetitive transcranial magnetic stimulation (rTMS) to produce a temporary disruption of this specific cortical site. METHODS Eighteen subjects were asked to detect facial expression of emotions (anger, fear, happiness, and neutrality) and to evaluate their empathic responsiveness to these facial cues. A 5-second rTMS (1 Hz, inhibition paradigm) pulse was delivered before the stimulus onset. RESULTS Error rates and response times (RTs) increased when brain activity was disrupted, specifically in response to anger and fear. Self-reported measures showed a concomitant decreased empathic response when the frontal sensorimotor system was deactivated. CONCLUSIONS The ability to monitor emotional cues and the behavioral empathic responsiveness to emotional situations was shown to be partially compromised in the case of frontal activity disruption, highlighting the main role of the sensorimotor system for empathic social skills.