Original Research ARTICLE
Patients with schizophrenia do not preserve automatic grouping when mentally re-grouping figures: shedding light on an ignored difficulty
- 1 INSERM U666, Department of Psychiatry I, Centre Hospitalier Régional de Strasbourg, Strasbourg, France
- 2 Laboratory for Neurology and Imaging of Cognition, University of Geneva, Geneva, Switzerland
- 3 Department of Neurology, Geneva University Hospital, Geneva, Switzerland
- 4 Laboratoire d’Imagerie et Neurosciences Cognitives, UMR 791 CNRS, Institut de Physique Biologique, Strasbourg, France
Looking at a pair of objects is easy when automatic grouping mechanisms bind these objects together, but visual exploration can also be more flexible. It is possible to mentally “re-group” two objects that are not only separate but belong to different pairs of objects. “Re-grouping” is in conflict with automatic grouping, since it entails a separation of each item from the set it belongs to. This ability appears to be impaired in patients with schizophrenia. Here we check if this impairment is selective, which would suggest a dissociation between grouping and “re-grouping,” or if it impacts on usual, automatic grouping, which would call for a better understanding of the interactions between automatic grouping and “re-grouping.” Sixteen outpatients with schizophrenia and healthy controls had to identify two identical and contiguous target figures within a display of circles and squares alternating around a fixation point. Eye-tracking was used to check central fixation. The target pair could be located in the same or separate hemifields. Identical figures were grouped by a connector (grouped automatically) or not (to be re-grouped). Attention modulation of automatic grouping was tested by manipulating the proportion of connected and unconnected targets, thus prompting subjects to focalize on either connected or unconnected pairs. Both groups were sensitive to automatic grouping in most conditions, but patients were unusually slowed down for connected targets while focalizing on unconnected pairs. In addition, this unusual effect occurred only when targets were presented within the same hemifield. Patients and controls differed on this asymmetry between within- and across-hemifield presentation, suggesting that patients with schizophrenia do not re-group figures in the same way as controls do. We discuss possible implications on how “re-grouping” ties in with ongoing, automatic perception in healthy volunteers.
Keywords: grouping, visual organization, schizophrenia, top-down grouping
Citation: Giersch A, van Assche M, Capa RL, Marrer C and Gounot D (2012) Patients with schizophrenia do not preserve automatic grouping when mentally re-grouping figures: shedding light on an ignored difficulty. Front. Psychology 3:274. doi: 10.3389/fpsyg.2012.00274
Received: 15 April 2012; Accepted: 17 July 2012;
Published online: 17 August 2012.
Edited by:Snehlata Jaswal, Indian Institute of Technology, India
Reviewed by:Alexandra Bendixen, University of Leipzig, Germany
Wolfgang Tschacher, Universität Bern, Switzerland
Copyright: © 2012 Giersch, van Assche, Capa, Marrer and Gounot. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Anne Giersch, INSERM U666, Department of Psychiatry I, Centre Hospitalier Régional de Strasbourg, Hôpital Civil, 1, pl de l’Hôpital, F-67091 Strasbourg Cedex, France. e-mail: firstname.lastname@example.org