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

Brian P. Keane, Danielle Paterno, Sabine Kastner, Bart Krekelberg, Steven M. Silverstein

Research output: Contribution to journalArticle

1 Scopus citations

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). Visual shape completion was quantified as the extent to which performance in the illusory condition exceeded that of the fragmented. Half of the trials incorporated wire edge elements, which augment contour salience and improve shape completion. Each patient group exhibited large visual shape completion deficits that could not be explained by differences in age, motivation, or orientation tuning. Patients responded normally to changes in illusory contour salience, indicating that they were forming but not adequately employing such contours for discriminating shapes. Shape completion deficits were most apparent for patients with cognitive disorganization, poor premorbid early adolescent functioning, and normal orientation discrimination. Visual shape completion deficits emerge maximally by the first psychotic episode and arise from higher-level disturbances that are related to premorbid functioning and disorganization.

Original languageEnglish (US)
Pages (from-to)57-68
Number of pages12
JournalJournal of Abnormal Psychology
Volume128
Issue number1
DOIs
StatePublished - Jan 2019

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All Science Journal Classification (ASJC) codes

  • Psychiatry and Mental health
  • Biological Psychiatry

Keywords

  • cognitive disorganization
  • illusory contours
  • premorbid functioning
  • schizophrenia
  • visual completion

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