Andrea Marie Pua¹ (), Alison Harris¹; ¹Claremont McKenna College

Action simulation theory proposes that we understand others’ internal states by recreating their actions with our own sensorimotor systems. Supporting this idea, electroencephalography (EEG) has shown that the sensorimotor mu rhythm (10-12 Hz) is reduced both during action execution and observation of others’ actions. Recently, we found weaker “mu suppression” for emotional actions, perhaps due to greater variability between individuals in their bodily expression of emotions. If so, we would expect greater mu suppression when observing one’s own emotional actions versus those of others. In this study, participants completed a two-session experiment in which point-light displays (PLDs) of affectively-neutral and emotional body movements were recorded with motion capture, followed by a separate session measuring their neural responses during observation of these PLDs by themselves and others. Because the PLDs removed other visual identifying information, discrimination depended solely on the pattern of whole-body movement. We found no significant mu suppression for participants’ own versus others’ emotional movements, suggesting that decreased action simulation for emotional actions is not simply due to reduced familiarity or ease of simulation. However, separate behavioral experiments confirmed that participants could successfully discriminate whether emotional movements were performed by themselves or another, despite limited visual familiarity with the PLDs. Exploratory EEG analyses implicated the beta band (14-40 Hz) in actor identity perception, consistent with proposed roles in motor inhibition and motor set maintenance. Although inconsistent with an action simulation account based on mu suppression, these results nonetheless support a role for sensorimotor representation of emotional actions.