title: Encoding dysfunctions in a dynamic-static paradigm for visuospatial working memory in first-episode psychosis patients: a 2-year follow-up study.
abstract: OBJECTIVE
  To investigate static and dynamic visuospatial working memory (VSWM) processes in first-episode psychosis (FEP) patients and explore the validity of such measures as specific trait markers of schizophrenia.
  
  
  METHODS
  Twenty FEP patients and 20 age-, sex-, laterality- and education-matched controls carried out a dynamic and static VSWM paradigm. At 2-year follow up 13 patients met Diagnostic and Statistical Manual (of Mental Health Disorders)--Fourth Edition (DSM-IV) criteria for schizophrenia, 1 for bipolar disorder, 1 for brief psychotic episode and 5 for schizotypal personality disorder.
  
  
  RESULTS
  Compared with controls, the 20 FEP patients showed severe impairment in the dynamic VSWM condition but much less impairment in the static condition. No specific bias in stimulus selection was detected in the two tasks. Two-year follow-up evaluations suggested poorer baseline scores on the dynamic task clearly differentiated the 13 FEP patients who developed schizophrenia from the seven who did not.
  
  
  CONCLUSIONS
  Results suggest deficits in VSWM in FEP patients. Specific exploratory analyses further suggest that deficit in monitoring-manipulation VSWM processes, especially involved in our dynamic VSWM task, can be a reliable marker of schizophrenia.
authors.affiliation: Institute of Sport Science and Physical Education, Department of Physiology, Lausanne University, Lausanne, Switzerland. lcocchi@unimelb.edu.au
authors.forename: Luca
authors.initials: L
authors.lastname: Cocchi
authors.forename: Martin
authors.initials: M
authors.lastname: Debbané
authors.forename: Pascal
authors.initials: P
authors.lastname: Vianin
authors.forename: Romaine
authors.initials: R
authors.lastname: Bircher
authors.forename: Sacha
authors.initials: S
authors.lastname: Roulin
authors.forename: Philippe
authors.initials: P
authors.lastname: Conus
authors.forename: Pascale
authors.initials: P
authors.lastname: Sarrasin-Bruchez
authors.forename: Pierre
authors.initials: P
authors.lastname: Bovet
authors.forename: Henri
authors.initials: H
authors.lastname: Volken
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Wood
authors.forename: Françoise
authors.initials: F
authors.lastname: Schenk
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000503:physiopathology / Q000523:psychology; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D011618:Psychotic Disorders / Q000469:parasitology* / Q000503:physiopathology; D012559:Schizophrenia / Q000503:physiopathology; D012565:Schizophrenic Psychology; D012569:Schizotypal Personality Disorder / Q000503:physiopathology / Q000523:psychology; D055815:Young Adult