Visual-Perceptual Dysfunctions Are Possible Endophenotypes of Schizophrenia Evidence From the Psychophysical Investigation of Magnocellular and Parvocellular Pathways

• Published in: Neuropsychology Vol. 19; no. 5; pp. 649 - 656
• Main Authors: Kéri, Szabolcs, Kelemen, Oguz, Janka, Zoltán, Benedek, György
• Format: Journal Article
• Language: English
• Published: Washington, DC American Psychological Association 01-09-2005
• Subjects: Adult and adolescent clinical studies; Afferent Pathways; Analysis of Variance; Biological and medical sciences; Cognitive Ability; Color Perception - physiology; Contrast Sensitivity - physiology; Endophenotype; Female; Human; Humans; Male; Medical sciences; Perceptual Disorders - etiology; Phenotypes; Photic Stimulation - methods; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychophysics - methods; Psychoses; Schizophrenia; Schizophrenia - genetics; Schizophrenia - physiopathology; Schizophrenic Psychology; Sensory Thresholds - physiology; Siblings; Vision Disorders; Visual Perception; endophenotype; magnocellular pathways; visual perception; schizophrenia; executive functions; Human; Executive function; Parvocellular pathway; Schizophrenia; Cognition; Psychophysics; Endophenotype; Psychosis; Magnocellular pathway; Dysfunction; Vision; Perception
• ISSN: 0894-4105; 1931-1559
• DOI: 10.1037/0894-4105.19.5.649

Visual information processing is impaired in schizophrenia patients and their biological relatives. The authors measured vernier thresholds in 72 schizophrenia patients, their 86 siblings, and 60 healthy control subjects. Subjects were asked to detect the direction of the horizontal displacement of 2 stimuli (left or right). During magnocellular (M) pathway tests, stimuli were dots with low contrast (5%) or counterphase-modulated gratings (25 Hz). For parvocellular (P) pathway tests, isoluminant blue-red dots with yellow-green background were used. Results revealed that patients with schizophrenia and their siblings were more impaired in M pathway conditions than in P pathway conditions. There was no color-specific impairment. The patients and their siblings displayed lower performances on tests of executive functions, psychomotor speed, and verbal memory compared with the controls. Visual-perceptual and neuropsychological data did not correlate. In conclusion, M pathway dysfunction is a potential endophenotype of schizophrenia.