A cross-modal system linking primary auditory and visual cortices: evidence from intrinsic fMRI connectivity analysis.
Recent anatomical and electrophysiological evidence in primates indicates the presence of direct connections between primary auditory and primary visual cortex that constitute cross-modal systems. We examined the intrinsic functional connectivity (fcMRI) of putative primary auditory cortex in 32 young adults during resting state scanning. We found that the medial Heschl's gyrus was strongly coupled, in particular, to visual cortex along the anterior banks of the calcarine fissure. This observation was confirmed using novel group-level, tensor-based independent components analysis. fcMRI analysis revealed that although overall coupling between the auditory and visual cortex was significantly reduced when subjects performed a visual perception task, coupling between the anterior calcarine cortex and auditory cortex was not disrupted. These results suggest that primary auditory cortex has a functionally distinct relationship with the anterior visual cortex, which is known to represent the peripheral visual field. Our study provides novel, fcMRI-based, support for a neural system involving low-level auditory and visual cortices.
Eckert
Mark A
MA
Department of Otolaryngology, Medical University of South Carolina, Charleston, South Carolina 29425, USA. eckert@musc.edu
Kamdar
Nirav V
NV
Chang
Catherine E
CE
Beckmann
Christian F
CF
Greicius
Michael D
MD
Menon
Vinod
V
D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology*; D025341:Principal Component Analysis; D014793:Visual Cortex / Q000502:physiology*