Processing of auditory location changes after horizontal head rotation.
Under natural conditions, our sound localization capabilities enable us to move constantly while keeping a stable representation of our auditory environment. However, since most auditory studies focus on head-restrained conditions, it is still unclear whether neurophysiological markers of auditory spatial processing reflect representation in a head-centered or an allocentric coordinate system. Therefore, we used human electroencephalography to test whether the spatial mismatch negativity (MMN) as a marker of spatial change processing is elicited by changes of sound source position in terms of a head-related or an allocentric coordinate system. Subjects listened to a series of virtually localized band-passed noise tones and were occasionally cued visually to conduct horizontal head movements. After these head movements, we presented deviants either in terms of a head-centered or an allocentric coordinate system. We observed significant MMN responses to the head-related deviants only but a change-related novelty P3-like component for both head-related and allocentric deviants. These results thus suggest that the spatial MMN is associated with a representation of auditory space in a head-related coordinate system and that the integration of motor output and auditory input possibly occurs at later stages of the auditory "where" processing stream.
Altmann
Christian F
CF
Institute of Medical Psychology, Goethe University, 60528 Frankfurt am Main, Germany. c.altmann@kt5.ecs.kyoto-u.ac.jp
Wilczek
Esther
E
Kaiser
Jochen
J
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D001931:Brain Mapping; D003265:Contingent Negative Variation / Q000502:physiology*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D019416:Head Movements; D006801:Humans; D008297:Male; D008875:Middle Aged; D011571:Psychoacoustics; D012399:Rotation; D013017:Sound Localization / Q000502:physiology*; D055815:Young Adult