Awareness in Primary Visual Cortex

The neural processes that give rise to visual awareness are currently the subject of much debate. One brain region in particular, the primary visual cortex (also known as striate cortex or V1), has been implicated in the neural interactions that give rise to conscious perception. This region, located in and around the calcarine fissure in the occipital lobe, was long regarded merely as a relay station for visual cortical input, with visual awareness believed to arise from the activity of highly specialized visual areas in the parietal and temporal lobes. The perceptual consequences of V1 lesions, however, reveal the indispensable role of this area in conscious perception, and this view is supported by recent neurodisruption and neuroimaging studies carried out in neurologically normal observers. Here we review findings from neuropsychology, cognitive neuroscience, and electrophysiology, and discuss what they reveal about the role of V1 in visual awareness.