Impaired Representation of Time in Schizophrenia Is Linked to Positive Symptoms and Cognitive Demand

PLoS One. 2013 Jun 27;8(6):e67615. doi: 10.1371/journal.pone.0067615. Print 2013.

Abstract

Time processing critically relies on the mesencephalic dopamine system and striato-prefrontal projections and has thus been suggested to play a key role in schizophrenia. Previous studies have provided evidence for an acceleration of the internal clock in schizophrenia that may be linked to dopaminergic pathology. The present study aimed to assess the relationship between altered time processing in schizophrenia and symptom manifestation in 22 patients and 22 controls. Subjects were required to estimate the time needed for a visual stimulus to complete a horizontal movement towards a target position on trials of varying cognitive demand. It was hypothesized that patients - compared to controls - would be less accurate at estimating the movement time, and that this effect would be modulated by symptom manifestation and task difficulty. In line with the notion of an accelerated internal clock due to dopaminergic dysregulation, particularly patients with severe positive symptoms were expected to underestimate movement time. However, if altered time perception in schizophrenia was better explained in terms of cognitive deficits, patients with severe negative symptoms should be specifically impaired, while generally, task performance should correlate with measures of processing speed and cognitive flexibility. Patients underestimated movement time on more demanding trials, although there was no link to disease-related cognitive dysfunction. Task performance was modulated by symptom manifestation. Impaired estimation of movement time was significantly correlated with PANSS positive symptom scores, with higher positive symptom scores associated with stronger underestimation of movement time. The present data thus support the notion of a deficit in anticipatory and predictive mechanisms in schizophrenia that is modulated both by symptom manifestation and by cognitive demand.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Case-Control Studies
  • Cognition Disorders / diagnosis*
  • Cognition Disorders / etiology
  • Cognition Disorders / psychology
  • Female
  • Humans
  • Male
  • Neuropsychological Tests
  • Schizophrenia / complications
  • Schizophrenia / physiopathology*
  • Schizophrenic Psychology
  • Time Perception*

Grants and funding

The present study was supported by a research grant awarded by the German Ministry of Education and Research (Bundesministerium für Bildung und Forschung, BMBF, grant number 01GW0740). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. With regard to publication fees, we acknowledge support by the Deutsche Forschungsgemeinschaft (DFG) and the Open Access Publication Fund of the University of Muenster, Germany.