Auditory attention activates peripheral visual cortex.
BACKGROUND
Recent neuroimaging studies have revealed that putatively unimodal regions of visual cortex can be activated during auditory tasks in sighted as well as in blind subjects. However, the task determinants and functional significance of auditory occipital activations (AOAs) remains unclear.


RESULTS
We examined AOAs in an intermodal selective attention task to distinguish whether they were stimulus-bound or recruited by higher-level cognitive operations associated with auditory attention. Cortical surface mapping showed that auditory occipital activations were localized to retinotopic visual cortex subserving the far peripheral visual field. AOAs depended strictly on the sustained engagement of auditory attention and were enhanced in more difficult listening conditions. In contrast, unattended sounds produced no AOAs regardless of their intensity, spatial location, or frequency.


CONCLUSIONS
Auditory attention, but not passive exposure to sounds, routinely activated peripheral regions of visual cortex when subjects attended to sound sources outside the visual field. Functional connections between auditory cortex and visual cortex subserving the peripheral visual field appear to underlie the generation of AOAs, which may reflect the priming of visual regions to process soon-to-appear objects associated with unseen sound sources.
Cate
Anthony D
AD
Human Cognitive Neurophysiology Laboratory, Veterans Administration Northern California Health Care System, Martinez, California, United States of America. acate@ebire.org
Herron
Timothy J
TJ
Yund
E William
EW
Stecker
G Christopher
GC
Rinne
Teemu
T
Kang
Xiaojian
X
Petkov
Christopher I
CI
Disbrow
Elizabeth A
EA
Woods
David L
DL
D000328:Adult; D001288:Attention; D005260:Female; D006309:Hearing; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D014793:Visual Cortex / Q000502:physiology*