In our environment our senses are bombarded with a myriad of signals, only a subset of which is relevant for our goals. Using sub-millimeter-resolution fMRI at 7T we resolved BOLD-response and activation patterns across cortical depth in early sensory cortices to auditory, visual and audiovisual stimuli under auditory or visual attention. In visual cortices, auditory stimulation induced widespread inhibition irrespective of attention, whereas auditory relative to visual attention suppressed mainly central visual field representations. In auditory cortices, visual stimulation suppressed activations, but amplified responses to concurrent auditory stimuli, in a patchy topography. Critically, multisensory interactions in auditory cortices were stronger in deeper laminae, while attentional influences were greatest at the surface. These distinct depth-dependent profiles suggest that multisensory and attentional mechanisms regulate sensory processing via partly distinct circuitries. Our findings are crucial for understanding how the brain regulates information flow across senses to interact with our complex multisensory world.
- Uta Noppeney
- Robert Turner
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Human subjects: All procedures were approved by the Ethics Committee of the University of Leipzig under the protocol number 273-14: "Magnetresonanz-Untersuchungen am Menschen bei 7 Tesla". Participants gave written informed consent to participate in this fMRI study.
- Floris P de Lange, Radboud University, Netherlands
© 2020, Gau et al.
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