Review article

Korean Journal of Schizophrenia Research 2011;14(2):61-75.

Visual Perception Deficits Associated with the Magnocellular Pathway in Schizophrenia

Jejoong Kim, PhD1 and Sohee Park, PhD2

Abstract

Although much has been written about the role of higher-order cognitive functions, such as memory, attention and executive control, relatively little is known about perceptual abnormalities in schizophrenia. Visual perception has reciprocal functional connection with higher cognitive functions and can affect behavioral outcome. Therefore, understanding mechanisms of visual deficits in schizophrenia will be helpful in elucidating the etiology of the illness, thereby contributing to the development of strategies for further assessments, efficient treatments and social rehabilitation. In this review, we surveyed representative psychophysical, electro-physiological, and neuroimaging studies that define characteristics of visual deficits in schizophrenia and elucidate underlying neural bases. Specifically, abnormalities associated with functions of the dorsal visual stream (e.g., prolonged visual masking effect, reduced EEG amplitude in visual areas, and impaired motion perception and eye movement) were summarized. After describing the visual deficits, we discussed the potential consequences of visual deficits in social outcome. Vision plays a key role in social cognition because precise and rapid processing of visual information is critical for survival and adaptive functioning in society. We examined the role of early visual deficits in social functioning with a particular focus on the processing of ‘socially-relevant’ visual stimuli (i.e. “biological motion”) in schizophrenia. Lastly, we discussed the possible influence of psychotropic medication on perception and the relationship between visual deficits and clinical symptoms. (Korean J Schizophr Res 2011;14:61-75)

Key Words: Perception , Visual pathways , Motion perception , Biological motion , fMRI , Social functioning , Key Words : Schizophrenia