title: Working memory task performance and chunking in early Alzheimer's disease.
abstract: BACKGROUND
  Chunking is a powerful encoding strategy that significantly improves working memory performance in normal young people.
  
  
  OBJECTIVE
  To investigate chunking in patients with mild Alzheimer's disease and in a control group of elderly people without cognitive impairment.
  
  
  METHODS
  People with mild Alzheimer's disease (n = 28) were recruited and divided according to Mini-Mental State Examination score into mild and very mild disease groups. A control group of 15 elderly individuals was also recruited. All participants performed digit and spatial working memory tasks requiring either unstructured sequences or structured sequences (which encourage chunking of information) to be recalled.
  
  
  RESULTS
  The control group and both disease groups performed significantly better on structured trials of the digit working memory tasks, indicating successful use of chunking strategies to improve verbal working memory performance. The control and very mild disease groups also performed significantly better on structured trials of the spatial task, whereas those with mild disease demonstrated no significant difference between the structured and unstructured spatial conditions.
  
  
  CONCLUSIONS
  The ability to use chunking as an encoding strategy to improve verbal working memory performance is preserved at the mild stage of Alzheimer's disease, whereas use of chunking to improve spatial working memory is impaired by this stage. Simple training in the use of chunking might be a beneficial therapeutic strategy to prolong working memory functioning in patients at the earliest stage of Alzheimer's disease.
authors.affiliation: Department of Old Age Psychiatry, Institute of Psychiatry, King's College London, PO Box 70, London SE5 8AF, UK. jonathan.huntley@kcl.ac.uk
authors.forename: Jonathan
authors.initials: J
authors.lastname: Huntley
authors.forename: Daniel
authors.initials: D
authors.lastname: Bor
authors.forename: Adam
authors.initials: A
authors.lastname: Hampshire
authors.forename: Adrian
authors.initials: A
authors.lastname: Owen
authors.forename: Robert
authors.initials: R
authors.lastname: Howard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000503:physiopathology*; D001245:Association Learning; D016022:Case-Control Studies; D018450:Disease Progression; D006801:Humans; D007361:Intelligence Tests; D008569:Memory Disorders / Q000503:physiopathology* / Q000628:therapy; D008570:Memory, Short-Term; D011939:Mental Recall; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010364:Pattern Recognition, Visual; D012720:Severity of Illness Index; D055815:Young Adult