title: Deconstructing spatial working memory and attention deficits in multiple sclerosis.
abstract: OBJECTIVE
  To investigate whether spatial working memory (WM) is impaired in multiple sclerosis (MS), and, if it is, to localize impairment to specific cognitive subprocess(es).
  
  
  METHODS
  In Experiment 1, MS and control participants performed computerized memory-span and visuomotor tasks. WM subprocesses were taxed by manipulating (1) the requirement to remember serial order, (2) delay duration, and (3) the presence of irrelevant stimuli during target presentation. In Experiment 2, recall and recognition tests varied the difficulty of WM retrieval. In Experiment 3, an attention-cueing task tested the ability to voluntarily and rapidly reorient attention.
  
  
  RESULTS
  Performance was worse for MS than for control participants in both spatial recall (Exp. 1 span: 95% CIMS = [5.11, 5.57], 95% CIControls = [5.58, 6.03], p = .003, 1-tailed; Exp. 2 span: 95% CIMS = [4.44, 5.54], 95% CIControls = [5.47, 6.57], p = .006, 1-tailed) and recognition (accuracy: 95% CIMS = [0.71, 0.81], 95% CIControls = [0.79, 0.88], p = .01, 1-tailed) tests. However, there was no evidence for deficits in spatiotemporal binding, maintenance, retrieval, distractor suppression, or visuomotor processing. In contrast, MS participants were abnormally slow to reorient attention (cueing effect (ms): 95% CIMS: [90, 169], 95% CIControls: [29, 107], p = .015, 1-tailed).
  
  
  CONCLUSIONS
  Results suggest that, whereas spatial WM is impaired in MS, once spatial information has been adequately encoded into WM, individuals with MS are, on average, able to maintain and retrieve this information. Impoverished encoding of spatial information, however, may be due to inefficient voluntary orienting of attention.
authors: Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218-2686, USA. gmeindl@jhu.edu
authors: Leon
authors: L
authors: Gmeindl
authors: Susan M
authors: SM
authors: Courtney
mesh_terms: D000328:Adult; D000368:Aged; D001288:Attention; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000209:etiology / Q000503:physiopathology*; D008570:Memory, Short-Term; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications / Q000503:physiopathology / Q000523:psychology*; D020528:Multiple Sclerosis, Chronic Progressive / Q000523:psychology; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000523:psychology; D011597:Psychomotor Performance