Vision in schizophrenia: why it matters.

Abstract

Visual processing impairments are now well established in schizophrenia, including abnormalities in: contrast sensitivity (Kiss et al., 2010; Kelemen et al., 2013); excitatory and inhibitory functions such as those involved in forward and backward masking (Green et al., 2011) and surround suppression (Dakin et al., 2005); perceptual organization (Silverstein and Keane, 2011a); facial emotion recognition (Turetsky et al., 2007) and motion processing (Chen, 2011). There has been little work on color processing to date, but clinical reports indicate frequent descriptions of increased intensity of, or change in colors, in addition to changes in brightness contrast (Vollmer-Larsen et al., 2007). Of etiological relevance, visual distortions (which occur in over 60% of patients) have the highest sensitivity for conversion to a psychotic disorder among all basic symptoms (Klosterkotter et al., 2001). In addition, visual impairments in children of parents with schizophrenia predict later development of the disorder (Schiffman et al., 2006), and visual abnormalities in children in the general population are more strongly associated with the later development of schizophrenia than any other form of sensory impairment (Schubert et al., 2005). Finally, seemingly subtle visual impairments contribute to poorer real-world functioning (Rassovsky et al., 2011; Green et al., 2012). In short, visual changes (e.g., distortions, hallucinations) are common, and they have etiological, pathophysiological, and functional significance. In some cases, they can be viewed as models of impaired neural circuitry that can inform our understanding of the same connectivity problems occurring at larger scales, such as in the frontal lobe, or involving connections between brain regions (Phillips and Silverstein, 2003).