EFFECTS OF VOLUNTARY MOVEMENTS ON EARLY AUDITORY BRAIN RESPONSES

It has not been clear whether or not early information processing in t he human auditory cortex is altered by voluntary movements. We report a movement-related, complex event-related potential consisting of rela tively long-lasting amplitude and phase perturbations induced in an on going auditory steady-state response (SSR) by brief self-paced finger movements. Our results suggest that processing in the auditory cortex during the first 50-100 ms after stimulus delivery is affected before, during, and after voluntary movements, beginning with a 1- to 2-ms de lay in the SSR wave form starting 1-2 s be fore the movement.