Cerebral responses to change in spatial location of unattended sounds.
The neural basis of spatial processing in the auditory cortex has been controversial. Human fMRI studies suggest that a part of the planum temporale (PT) is involved in auditory spatial processing, but it was recently argued that this region is active only when the task requires voluntary spatial localization. If this is the case, then this region cannot harbor an ongoing spatial representation of the acoustic environment. In contrast, we show in three fMRI experiments that a region in the human medial PT is sensitive to background auditory spatial changes, even when subjects are not engaged in a spatial localization task, and in fact attend the visual modality. During such times, this area responded to rare location shifts, and even more so when spatial variation increased, consistent with spatially selective adaptation. Thus, acoustic space is represented in the human PT even when sound processing is not required by the ongoing task.
Deouell
Leon Y
LY
Department of Psychology and the Interdisciplinary Center for Neural Computation, The Hebrew University of Jerusalem, Jerusalem 91905, Israel. msleon@huji.ac.il
Heller
Aaron S
AS
Malach
Rafael
R
D'Esposito
Mark
M
Knight
Robert T
RT
D000161:Acoustic Stimulation; D000328:Adult; D001288:Attention / Q000502:physiology*; D001303:Auditory Cortex / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010898:Pitch Perception / Q000502:physiology; D013017:Sound Localization / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*