title: Visual-spatial episodic memory in schizophrenia: A multiple systems framework.
abstract: OBJECTIVE
  Enhanced understanding of cognitive deficits, and the neurobiological abnormalities that mediate them, can be achieved through translational research that employs comparable experimental approaches across species. This study employed a multiple-systems framework derived from the rodent literature to investigate visual-spatial memory abilities associated with schizophrenia.
  
  
  METHODS
  Using the bin task, a human analog of rodent maze tasks, everyday objects were hidden in visually identical bins. Following a 1-min filled delay, participants with schizophrenia-spectrum disorders (n = 30) and healthy community controls (n = 30) were asked to identify both the object hidden and bin used on the basis of its spatial location. Three dimensions of visual-spatial memory were contrasted: (a) memory for spatial locations versus memory for objects, (b) allocentric (viewpoint independent) versus egocentric (body-centered) spatial representations, and (c) event (working) memory versus reference memory.
  
  
  RESULTS
  Most pronounced was a differential deficit in memory for spatial locations under allocentric (p = .005, d = -0.77) but not egocentric viewing conditions (p = .298, d = -0.28) in the schizophrenia group relative to healthy controls. Similarly, schizophrenia-related spatial memory deficits were pronounced under demands for event memory (p = .004, d = -0.77) but not reference memory (p = .171, d = -0.33).
  
  
  CONCLUSIONS
  These results support a heuristic of preferential deficits in hippocampal-mediated forms of memory in schizophrenia. Moreover, the task provides a useful paradigm for translational research and the pattern of deficits suggests that persons with schizophrenia may benefit from mnemonic approaches favoring egocentric representations and consistency when interacting with our visual-spatial world.
authors.affiliation: Department of Psychology, Ryerson University.
authors.forename: Todd A
authors.identifier: 0000-0002-7204-5684
authors.initials: TA
authors.lastname: Girard
authors.affiliation: Department of Psychiatry and Behavioural Neurosciences, McMaster University.
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Christensen
authors.affiliation: School of Medicine, McMaster University.
authors.forename: Michael G
authors.initials: MG
authors.lastname: DeGroote
authors.affiliation: Neuroscience, Pharmaceutical Sciences, University of Toronto.
authors.forename: Sakina
authors.initials: S
authors.lastname: Rizvi
mesh_terms: D000328:Adult; D003627:Data Interpretation, Statistical; D005260:Female; D006624:Hippocampus / Q000502:physiology; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D021641:Recognition, Psychology; D012565:Schizophrenic Psychology; D012727:Sex Characteristics; D013028:Space Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*