title: Fractionation of visuo-spatial memory processes in bipolar depression: a cognitive scaffolding account.
abstract: BACKGROUND
  Previous studies of neurocognitive performance in bipolar disorder (BD) have demonstrated impairments in visuo-spatial memory. The aim of the present study was to use an object-location memory (OLM) paradigm to assess specific, dissociable processes in visuo-spatial memory and examine their relationship with broader neurocognitive performance.
  
  
  METHODS
  Fifty participants (25 patients with BD in a current depressive episode and 25 matched healthy controls) completed the OLM paradigm which assessed three different aspects of visuo-spatial memory: positional memory, object-location binding, and a combined process. Secondary neurocognitive measures of visuo-spatial memory, verbal memory, attention and executive function were also administered.
  
  
  RESULTS
  BD patients were significantly impaired on all three OLM processes, with the largest effect in exact positional memory (d = 1.18, p < 0.0001). General deficits were also found across the secondary neurocognitive measures. Using hierarchical regression, verbal learning was found to explain significant variance on the OLM measures where object-identity was present (the object-location binding and combined processes) and accounted for the group difference. The group difference in precise positional memory remained intact.
  
  
  CONCLUSIONS
  This study demonstrates that patients with bipolar depression manifest deficits in visuo-spatial memory, with substantial impairment in fine-grain, positional memory. The differential profile of processes underpinning the visuo-spatial memory impairment suggests a form of 'cognitive scaffolding', whereby performance on some measures can be supported by verbal memory. These results have important implications for our understanding of the functional cognitive architecture of mood disorder.
authors: Institute of Neuroscience, Newcastle University,Newcastle upon Tyne,UK.
authors: P
authors: P
authors: Gallagher
authors: Institute of Neuroscience, Newcastle University,Newcastle upon Tyne,UK.
authors: J M
authors: JM
authors: Gray
authors: Donders Institute for Brain Cognition and Behaviour, Radboud University,Nijmegen,The Netherlands.
authors: R P C
authors: RP
authors: Kessels
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001288:Attention; D001714:Bipolar Disorder / Q000150:complications* / Q000503:physiopathology*; D016022:Case-Control Studies; D003071:Cognition; D003863:Depression / Q000503:physiopathology*; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000175:diagnosis*; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D065852:Spatial Memory; D014706:Verbal Learning; D055815:Young Adult
keywords: Bipolar disorder; depression; neuropsychology; spatial memory; verbal memory