MISMATCH RESPONSE OF THE HUMAN BRAIN TO CHANGES IN SOUND LOCATION

WE investigated whether the enhanced negativity of the human event-rel ated brain potential elicited by changes in auditory lateralization is due to a higher change-detection process or whether it can be explain ed exclusively in terms of selective sensory adaptation. Infrequent ch anges in lateralization of a repetitive standard tone, generated by ch anges in interaural time differences, elicited a frontocentrally distr ibuted negative brain wave in the 100-250 ms range relative to stimulu s onset. This brain wave was also elicited when possible sensory adapt ation was prevented by controlling for the state of refractoriness of location-specific neurones. The results demonstrate that changes in la teralization elicit a genuine mismatch negativity (MMN), indicating th e activity of an automatic higher-order change-detection process.