The role of gaze and motor inhibition during action observation

A relevant source of information for social interaction is provided by other’s eye gaze and body movements. By using transcranial magnetic stimulation (TMS) on primary motor cortex, we assessed to what degree the coupling of observed action and gaze direction – simultaneously pointing toward a salient object – affects onlookers’ motor responses. Results showed an inhibitory pattern in observers’ muscles when the actor’s gaze and gesture were concurrently pointing to the salient object. This motor pattern was positively correlated with the ‘willingness to interact’, as reported by participants in a following questionnaire. In particular, the higher was the tendency to interact, the higher was the inhibitory pattern of activity in the muscle required to interact with the actor. Overall, these data seem to indicate that the joint contribution of gaze and request gesture increases participants’ proactivity, so that muscular inhibition is needed to prevent unwanted overt reactions.