Mesoscale cortical mechanisms of perceptual conflict resolution in binocular rivalry.

How does the human brain resolve conflicts in sensory input to generate conscious perception? Using high-resolution 7 T functional MRI, we addressed this question by investigating column- and layer-specific activity in cortical and subcortical regions in humans during binocular rivalry. The results show that eye-specific rivalry arises from interocular inhibition between adjacent ocular dominance columns in the superficial layers of the primary visual cortex, but not between ocular layers of the lateral geniculate nucleus of the thalamus. Eye-specific feedback from the intraparietal sulcus plays an active role in biasing and synchronizing local competitions in the primary visual cortex into perceptually coherent representations, even without awareness of eye-of-origin information. These findings reveal the mesoscale mechanisms of perceptual conflict resolution in humans: local conflicts in sensory input are resolved by inhibitory microcircuits in the sensory cortex, while feedback signals from the parietal attention network bias and integrate local competitions into unified conscious perception.