Sensory suppression effects to self-initiated sounds reflect the attenuation of the unspecific N1 component of the auditory ERP.

The suppression of the auditory N1 event-related potential (ERP) to self-initiated sounds became a popular tool to tap into sensory-specific forward modeling. It is assumed that processing in the auditory cortex is attenuated due to a match between sensory stimulation and a specific sensory prediction afforded by a forward model of the motor command. The present study shows that N1 suppression was dramatically increased with long (≈ 3 s) stimulus onset asynchronies (SOA), whereas P2 suppression was equal in all SOA conditions (0.8, 1.6, 3.2 s). Thus, the P2 was found to be more sensitive to self-initiation effects than the N1 with short SOAs. Moreover, only the unspecific but not the sensory-specific N1 components were suppressed for self-initiated sounds suggesting that N1-suppression effects mainly reflect an attenuated orienting response. We argue that the N1-suppression effect is a rather indirect measure of sensory-specific forward models.