Intact figure-ground segmentation in schizophrenia.
As revealed by backward masking studies, schizophrenic patients show strong impairments of early visual processing. However, the underlying temporal mechanisms are not yet well understood. To shed light on the exact timing of these deficits, we employed a paradigm in which two masks follow each other. We investigated 16 medicated schizophrenic patients and a matched group of 14 controls with a new backward masking technique, shine-through. In accordance with other masking studies, schizophrenic patients require a dramatically longer processing time to reach a predefined performance level compared with healthy subjects. However, patients are surprisingly sensitive to subtle differences in the timing of the two masks, revealing good temporal resolution. This good temporal resolution indicates intact and fast perceptual grouping and figure-ground segmentation in spite of high susceptibility to masking procedures in schizophrenia.
Herzog
Michael H
MH
Laboratory of Psycophysics, Brain Mind Institute, EPFL, 1015 Lausanne, Switzerland. michael.herzog@epfl.ch
Kopmann
Sabine
S
Brand
Andreas
A
D000328:Adult; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000175:diagnosis / Q000209:etiology*; D010470:Perceptual Masking; D012559:Schizophrenia / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D012565:Schizophrenic Psychology; D013998:Time Perception; D014796:Visual Perception / Q000502:physiology