Motor‐induced suppression of auditory neural responses to pitch‐shifted voice feedback.

Surviving in an alien world is dependent upon the ability to distinguish between sensory inputs arising from self‐actions and those of the others. In the auditory system, the motor‐driven predictions about expected sensory feedback (efference copies) are proposed to suppress sensory neural responses to self‐voice feedback that is predicted by the efference copies. In the present study, event‐related potentials were recorded in response to five different magnitudes (0, 50, 100, 200, and 400 cents) of pitch shift stimuli at voice onset during active vocal production and passive listening to the playback. Results indicated that the suppression of N1 component during vocal production was largest for normal voice feedback (PSS: 0 cents) and became smaller as the magnitude of pitch shift stimuli increased. For the largest tested PSS magnitude (400 cents), the N1 suppression was completely eliminated. One possible explanation for this effect is that the brain utilizes the motor predictions (efference copies) to suppress the auditory feedback of self‐generated vocalizations. The reduction of suppression for 50, 100, and 200 cents pitch shifts in voice feedback and its elimination for 400 cents stimuli provide supporting evidence for the idea that motor‐driven predictions provide mechanisms that lead to distinctly different sensory neural processing of self versus non‐self vocalizations.