Different responses of the right superior temporal sulcus to visual movement feedback during self-generated vs. externally generated hand movements.

An important implication of several recent accounts of motor control is that sensory feedback from self-generated movements is relatively attenuated based on predictions issued by the agent's motor system. Such a relative attenuation of sensory information during actions has already been demonstrated in the somatosensory domain. Here, we used functional magnetic resonance imaging (fMRI) and a virtual reality-based setup to investigate a potential attenuation of brain responses to realistic visual movement feedback during active vs. passive right-hand movements. The participants' right unseen hand was rotated either by the participants themselves or by the experimenter, while the participants received visual movement feedback via a photorealistic virtual 3D hand driven by their real hand movements, or received no visual feedback. We observed a significant interaction between movement type (active vs. passive) and movement feedback (vision vs. no vision) in the right superior temporal sulcus (STS), which showed relatively attenuated blood-oxygen-level-dependent (BOLD) signal differences in movements with vs. without visual feedback when those movements were actively vs. passively executed. This finding suggests that STS activity caused by visual feedback from the moving body may be attenuated based on the agent's motor predictions.