Vernier Threshold in Patients With Schizophrenia and in Their Unaffected Siblings

• Published in: Neuropsychology Vol. 18; no. 3; pp. 537 - 542
• Main Authors: Kéri, Szabolcs, Kelemen, Oguz, Benedek, György, Janka, Zoltán
• Format: Journal Article
• Language: English
• Published: Washington, DC American Psychological Association 01-07-2004
• Subjects: Adult; Adult and adolescent clinical studies; Biological and medical sciences; Color Perception - physiology; Contrast Sensitivity - physiology; Discrimination Learning - physiology; Female; Geniculate Bodies - physiopathology; Human; Humans; Male; Medical sciences; Middle Aged; Orientation - physiology; Pattern Recognition, Visual - physiology; Perceptual Disorders - diagnosis; Perceptual Disorders - genetics; Perceptual Disorders - physiopathology; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychophysics; Psychoses; Reference Values; Retinal Ganglion Cells - physiology; Schizophrenia; Schizophrenia - diagnosis; Schizophrenia - genetics; Schizophrenia - physiopathology; Schizophrenic Psychology; Sensory Thresholds - physiology; Siblings; Visual Acuity; Visual Acuity - physiology; Visual Cortex - physiopathology; Visual Pathways - physiopathology; Visual Perception - genetics; Visual Perception - physiology; Visual Thresholds; Visuospatial Ability; Psychosis; Vernier acuity; Human; Magnocellular pathway; Visual pathway; Family study; Vision; Parvocellular pathway; Schizophrenia; Perception; Cognition; Sibling
• ISSN: 0894-4105; 1931-1559
• DOI: 10.1037/0894-4105.18.3.537

The aim of this study was to investigate magnocellular (M) and parvocellular (P) visual functions in nonmedicated patients with schizophrenia and in their unaffected siblings. Possible abnormalities in cortical integration of retinal receptive fields also were addressed. Twenty-two nonmedicated patients with schizophrenia, their unaffected siblings, and 20 age- and IQ-matched healthy control subjects received 4 vernier acuity tasks (blue-on-yellow, frequency-doubling, achromatic low and high contrast conditions) in which they were asked to detect the spatial alignment of dots and gratings. Results revealed that the patients with schizophrenia and their unaffected siblings showed selective dysfunctions in the frequency-doubling and achromatic low contrast conditions, which were devoted to investigate M pathways. In the isoluminant blue-on-yellow and high contrast achromatic conditions, there were no significant differences between the experimental groups. These results suggest that the deficit of M pathway is an endophenotype of schizophrenia.