Cerebral Cortex Advance Access published online on December 17, 2007
Cerebral Cortex, doi:10.1093/cercor/bhm226
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Fundamental Requirements for Primary Visual Perception
1 Department of Neurology, University of Massachusetts Medical School, Worcester, MA 0l655, USA, 2 Vision Lab, Department of Psychology, Harvard College, Cambridge, MA 02138, USA
Address correspondence to Dr Dan Pollen, Department of Neurology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 0l655 USA. Email: pollend{at}ummhc.org
A novel perspective for the necessary and sufficient conditions for primary visual perception is proposed based upon relating recent discoveries from the visual sciences to relevant foundational neurological observations. This analysis suggests that a fundamental requirement for the emergence of normal primary visual perception is the coupling between the early visual cortices in the occipital lobe subserving image content with specific areas in the parietal lobe subserving selective attention, representations of extrapersonal space, the body schema, and the initiation of perceptual ownership. Fully intact primary visual perception, which includes the normal placement of image content within extrapersonal space, seems to require at each instant a mutually consistent completeness and corresponding removal of ambiguities in each of the linked neural representations subserving image, space and self. Experimental approaches that could either invalidate or strengthen the proposed framework are suggested as well as opportunities to differentiate some aspects of normal primary visual perception from the severely compromised visual experience that survives bilateral parieto-occipital lesions (Balint's syndrome) when visual experience may persist for single but unlocalizable objects.
Key Words: consciousness • parietal lobes • sense of self • vision • visual cortex • visual perception