title: Visual organization processes in schizophrenia.
abstract: Patients with schizophrenia are known to be impaired at organizing and exploring the visual environment. However, these impairments vary across studies, and the conditions determining whether patients are impaired or not are unclear. We aim to clarify this question by distinguishing different types of visual organization processes. A total of 23 patients and matched controls had to identify 2 identical figures embedded in a global structure made of connectors linking figures by pairs. The 2 targets belonged to either the same perceptual group (linked by a connector) or 2 different pairs (not linked by a connector). In a neutral condition, no connectors were presented. Top-down processes were explored by manipulating the proportion of targets linked or not by a connector in 3 experimental blocks. Patients needed the same processing time as controls to extract targets linked by a connector from the global structure. They could also focus on connectors when incited to do so. Impairments were observed for targets that were part of different pairs. Extracting such targets is effortful and time consuming, and both groups were slower in this condition than in the neutral condition. However, patients were slowed less than controls. This paradoxical improvement illustrates the fact that patients do not structure visual elements that are part of a global structure and not automatically bound together. Our results suggest this is due to impaired top-down processes.
authors.affiliation: INSERM U666, Department of Psychiatry, Centre Hospitalier Régional de Strasbourg, Strasbourg Cedex, France.
authors.forename: Mitsouko
authors.initials: M
authors.lastname: van Assche
authors.forename: Anne
authors.initials: A
authors.lastname: Giersch
mesh_terms: D000328:Adult; D001245:Association Learning; D001288:Attention; D004192:Discrimination, Psychological; D005260:Female; D005364:Field Dependence-Independence; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual; D010468:Perceptual Disorders / Q000175:diagnosis* / Q000523:psychology; D011930:Reaction Time; D012016:Reference Values; D014796:Visual Perception
references.citation: Psychon Bull Rev. 1994 Mar;1(1):29-55
references.pmid: 24203413
references.citation: Psychiatry Res. 2006 Dec 7;145(2-3):105-17
references.pmid: 17081620
references.citation: Schizophr Res. 2000 May 25;43(1):11-20
references.pmid: 10828411
references.citation: J Abnorm Psychol. 1980 Jun;89(3):409-18
references.pmid: 7410708
references.citation: Int J Neuropsychopharmacol. 2006 Dec;9(6):695-704
references.pmid: 16321171
references.citation: Schizophr Bull. 1987;13(2):261-76
references.pmid: 3616518
references.citation: Psychol Bull. 2005 Jul;131(4):618-632
references.pmid: 16060805
references.citation: Schizophr Res. 2005 Jun 15;75(2-3):183-92
references.pmid: 15885509
references.citation: J Abnorm Psychol. 1996 Aug;105(3):410-20
references.pmid: 8772011
references.citation: Biol Psychiatry. 2002 Aug 15;52(4):338-48
references.pmid: 12208641
references.citation: Behav Brain Sci. 2003 Feb;26(1):65-82; discussion 82-137
references.pmid: 14598440
references.citation: Arch Gen Psychiatry. 2006 Dec;63(12):1313-23
references.pmid: 17146006
references.citation: Psychiatry Clin Neurosci. 2003 Aug;57(4):409-15
references.pmid: 12839523
references.citation: Schizophr Res. 2005 Apr 1;74(1):69-79
references.pmid: 15694756
references.citation: J Abnorm Psychol. 1984 May;93(2):231-4
references.pmid: 6725757
references.citation: Perception. 1994;23(4):399-409
references.pmid: 7991341
references.citation: Schizophr Res. 2007 Sep;95(1-3):205-14
references.pmid: 17681736
references.citation: Perception. 1988;17(2):229-47
references.pmid: 3226865
references.citation: Biol Psychiatry. 2003 Dec 1;54(11):1134-48
references.pmid: 14643080
references.citation: Schizophr Res. 1994 Sep;13(2):117-26
references.pmid: 7986768
references.citation: Biol Psychiatry. 2008 Jul 1;64(1):34-9
references.pmid: 18374901
references.citation: J Abnorm Psychol. 2008 Feb;117(1):132-42
references.pmid: 18266491
references.citation: Cogn Neuropsychol. 2000 Dec 1;17(8):731-59
references.pmid: 20945203
references.citation: J Exp Psychol Hum Percept Perform. 2002 Oct;28(5):1071-84
references.pmid: 12421056
references.citation: J Abnorm Psychol. 2001 Feb;110(1):67-75
references.pmid: 11261402
references.citation: Cogn Neuropsychiatry. 2008 Sep;13(5):385-405
references.pmid: 18781493
references.citation: J Abnorm Psychol. 1997 Nov;106(4):530-8
references.pmid: 9358683
references.citation: Vision Res. 1994 Dec;34(24):3361-9
references.pmid: 7863619
references.citation: Percept Psychophys. 2007 Jan;69(1):68-78
references.pmid: 17515217
references.citation: Cogn Neuropsychiatry. 2006 Mar;11(2):112-32
references.pmid: 16537237
references.citation: Acta Psychol (Amst). 1999 Mar;101(1):3-25
references.pmid: 10100453
references.citation: Schizophr Bull. 2007 Jan;33(1):142-56
references.pmid: 17118973
references.citation: Neurosci Lett. 2004 Mar 4;357(2):131-4
references.pmid: 15036592