Auditory cortex responses to the transition from monophonic to pseudo-stereo sound.
Human cortical responses to the change in spaciousness of sound were recorded with the method of magnetoencephalography (MEG). The phases of dichotically presented 500-Hz tones were shifted so that the sound was perceived as originating either from a point-like source centered in the head or from separated sources in space. The phase shift was embedded in 40-Hz amplitude modulation. Thus, the phase shift could not be detected from a monaural signal. The transition between 'mono' and 'pseudo-stereo' quality of the sound elicited a P1-N1-P2 response similar to the onset response as well as a decrement in the steady-state response. The responses were discussed as reflecting binaural processing in the central auditory system.
Ross
B
B
The Rotman Research Institute, Baycrest Centre for Geriatric Care, Toronto, ON, Canada. bernhard.ross@ieee.org
Herdman
At T
AT
Wollbrink
A
A
Pantev
C
C
D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D008875:Middle Aged