crowding deficits in the visual periphery of schizophrenia patients拥挤在精神分裂症患者的视觉外围国家赤字.pdfVIP

Crowding Deficits in the Visual Periphery of Schizophrenia Patients 1,2 1,2 2 1 Rainer Kraehenmann , Franz X. Vollenweider , Erich Seifritz , Michael Kometer * 1 Neuropsychopharmacology and Brain Imaging Heffter Research Center, Clinic of Affective Disorders and General Psychiatry, Psychiatric University Hospital, University of Zurich, Zurich, Switzerland, 2 Clinic of Affective Disorders and General Psychiatry, Psychiatric University Hospital, University of Zurich, Zurich, Switzerland Abstract Accumulating evidence suggests that basic visual information processing is impaired in schizophrenia. However, deficits in peripheral vision remain largely unexplored. Here we hypothesized that sensory processing of information in the visual periphery would be impaired in schizophrenia patients and, as a result, crowding – the breakdown in target recognition that occurs in cluttered visual environments – would be stronger. Therefore, we assessed visual crowding in the peripheral vision of schizophrenia patients and healthy controls. Subjects were asked to identify a target letter that was surrounded by distracter letters of similar appearance. Targets and distracters were displayed at 8u and 10u of visual angle from the fixation point (eccentricity), and target-distracter spacing was 2u, 3u, 4u, 5u, 6u, 7u or 8u of visual angle. Eccentricity and target- distracter spacing were randomly varied. Accuracy was defined as the proportion of correctly identified targets. Critical spacing was defined as the spacing at which target identification accuracy began to deteriorate, and was assessed at viewing eccentricities of 8u and 10u. Schizophrenia patients were less acc