Clarifying the relationship between trait empathy and action-based resonance indexed by EEG mu-rhythm suppression.

Sensorimotor resonance, the vicarious activation of the sensory motor system during observation of another's actions, is thought to contribute to important social functions including empathy. Previous research has shown that sensorimotor resonance, as measured by suppression of the electrophysiological (EEG) mu rhythm, is predicted by trait empathy, but findings are inconsistent. Here we report data from a high-powered study (N = 252) to clarify the relationship between sensorimotor resonance as indexed by mu suppression during action observation and trait empathy as measured by the well-established Interpersonal Reactivity Index (IRI). Our initial pre-registered analyses at central electrode locations indicate that sensorimotor resonance is unrelated to general trait empathy or its sub-facets, however, these effects could not be isolated from attention-related occipital alpha. An additional non-registered analysis using Independent Component Analysis (ICA) to look at the isolated central mu-component clarified the relationship. Results confirmed the lack of a relationship between the mu-component and the perspective taking, personal distress, or fantasy facets of the IRI, but suggest a possible association with empathic concern such that greater resonance is associated with greater empathic concern. These results question the previously assumed relationship between trait empathy and sensorimotor resonance and highlight the need to investigate experience sharing tendencies in the context of simulation-based resonance.