Intact illusory contour formation but equivalently impaired visual shape completion in first- and later-episode schizophrenia.

ABSTRACT: Visual shape completion is a fundamental process that constructs contours and shapes on the basis of the geometric relations between spatially separated edge elements. People with schizophrenia are impaired at distinguishing visually completed shapes, but when does the impairment emerge and how does it evolve with illness duration? The question bears on the debate as to whether cognition declines after illness onset. To address the issue, we tested healthy controls (n = 48), first-episode psychosis patients (n = 23), and chronic schizophrenia patients (n = 49) on a classic psychophysical task in which subjects discriminated the relative orientations of four sectored circles that either formed or did not form visually completed shapes (illusory and fragmented conditions, respectively). Visu

SUBMITTER: Keane BP 

PROVIDER: S-EPMC6667222 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature