16. WHAT VISUAL PERCEPTUAL ANOMALIES CAN TELL US ABOUT SCHIZOPHRENIA: NEURAL MECHANISMS AND THEIR DIAGNOSTIC SPECIFICITY

A quarter of patients with schizophrenia endorse visual hallucinations while two-thirds report subtle perceptual anomalies of visual experience. Yet, little is known about the origin of these visual disturbances and their significance to the disorder. Does schizophrenia represent a unique class of perceptual anomalies or do common mechanisms affect other disorders? Understanding the nature of this defining feature of schizophrenia could help elucidate etiology and address whether visual perceptual phenomena should be considered diagnostic. This symposium will present new findings from four independent laboratories regarding the nature and diagnostic specificity of visual disturbances in schizophrenia. Brian Keane will present results demonstrating visual shape completion deficits in first-episode and chronic schizophrenia patients (d>.8; p