Simultaneous pitches are encoded separately in auditory cortex: an MMNm study.
This study examined whether two simultaneous pitches have separate memory representations or an integrated representation in preattentive auditory memory. Mismatch negativity fields were examined when a pitch change occurred in either the higher-pitched or the lower-pitched tone at 25% probability each, thus making the total deviation rate of the two-tone dyad 50%. Clear MMNm was obtained for deviants in both tones confirming separate memory traces for concurrent tones. At the same time, deviants to the lower-pitched, but not higher-pitched, tone within the two-tone dyad elicited a reduced MMNm compared to when each tone was presented alone, indicating that the representations of two pitches are not completely independent.
Fujioka
Takako
T
Rotman Research Institute, Baycrest, University of Toronto, Canada. tfujioka@rotman-baycrest.on.ca
Trainor
Laurel J
LJ
Ross
Bernhard
B
D000161:Acoustic Stimulation; D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D010898:Pitch Perception / Q000502:physiology*