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Working memory task performance and chunking in early Alzheimer's disease

  • Jonathan Huntley (a1), Daniel Bor (a2), Adam Hampshire (a3), Adrian Owen (a3) and Robert Howard (a4)...

Chunking is a powerful encoding strategy that significantly improves working memory performance in normal young people.


To investigate chunking in patients with mild Alzheimer's disease and in a control group of elderly people without cognitive impairment.


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.


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.


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.

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Corresponding author
Jonathan D. Huntley, Department of Old Age Psychiatry, Institute of Psychiatry, King's College London, PO Box 70, London SE5 8AF, UK. Email:
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1 Huntley, JD, Howard, RJ. Working memory in early Alzheimer's disease: a neuropsychological review. Int J Geriatr Psychiatry 2010; 25: 121–32.
2 Belleville, S, Chertkow, H, Gauthier, S. Working memory and control of attention in persons with Alzheimer's disease and mild cognitive impairment. Neuropsychology 2007; 21: 458–69.
3 Germano, C, Kinsella, GJ, Storey, E, Ong, B, Ames, D. The episodic buffer and learning in early Alzheimer's disease. J Clin Exp Neuropsychol 2008; 30: 627–38.
4 Bor, D, Duncan, J, Wiseman, RJ, Owen, AM. Encoding strategies dissociate prefrontal activity from working memory demand. Neuron 2003; 37: 361–7.
5 Bor, D, Cumming, N, Scott, CE, Owen, AM. Prefrontal cortical involvement in verbal encoding strategies. Eur J Neurosci 2004; 19: 3365–70.
6 Ericcson, KA, Chase, WG, Faloon, S. Acquisition of a memory skill. Science 1980; 208: 1181–2.
7 Olesen, PJ, Westerberg, H, Klingberg, T. Increased prefrontal and parietal activity after training of working memory. Nat Neurosci 2004; 7: 75–9.
8 McNab, F, Varrone, A, Farde, L, Jucaite, A, Bystritsky, P, Forssberg, H, et al. Changes in cortical dopamine D1 receptor binding associated with cognitive training. Science 2009; 323: 800–2.
9 Folstein, MF, Folstein, SE, McHugh, PR. ‘Mini-mental state’. A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975; 12: 189–98.
10 World Health Organization. International Statistical Classification of Diseases and Related Health Problems (ICD-10). WHO, 1992.
11 McKhann, G, Drachman, D, Folstein, M, Katzman, R, Price, D, Stadlan, EM. Clinical diagnosis of Alzheimer's disease: report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer's Disease. Neurology 1984; 34: 939–44.
12 Rosen, WG, Mohs, RC, Davis, KL. A new rating scale for Alzheimer's disease. Am J Psychiatry 1984; 141: 1356–64.
13 Wechsler, D. Wechsler Memory Scale (3rd edn). Psychological Corporation, 1998.
14 Yesavage, JA, Brink, TL, Rose, TL, Lum, O, Huang, V, Adey, M, et al. Development and validation of a geriatric depression screening scale: a preliminary report. J Psychiatr Res 1983; 17: 3749.
15 Nelson, H, Willison, J. National Adult Reading Test. nferNelson, 1991.
16 Bor, D, Owen, AM. A common prefrontal-parietal network for mnemonic and mathematical recoding strategies within working memory. Cereb Cortex 2007; 17: 778–86.
17 Milner, B. Interhemispheric differences in the localization of psychological processes in man. Br Med Bull 1971; 27: 272–7.
18 Baddeley, A. The episodic buffer: a new component of working memory? Trends Cogn Sci 2000; 4: 417–23.
19 Perry, RJ, Hodges, JR. Attention and executive deficits in Alzheimer's disease. A critical review. Brain 1999; 122: 383404.
20 Carlesimo, GA, Fadda, L, Lorusso, S, Caltagirone, C. Verbal and spatial memory spans in Alzheimer's and multi-infarct dementia. Acta Neurol Scand 1994; 89: 132–8.
21 Goldman-Rakic, PS. The prefrontal landscape: implications of functional architecture for understanding human mentation and the central executive. In The Prefrontal Cortex: Executive and Cognitive Functions (eds Roberts, AC, Robbins, TW, Weiskrantz, L): 87102. Oxford University Press, 1998.
22 Miller, EK, Cohen, JD. An integrative theory of prefrontal cortex function. Annu Rev Neurosci 2001; 24: 167202.
23 Owen, AM. The functional organization of working memory processes within human lateral frontal cortex: the contribution of functional neuroimaging. Eur J Neurosci 1997; 9: 1329–39.
24 Cabeza, R, Nyberg, L. Imaging cognition II: an empirical review of 275 PET and fMRI studies. J Cogn Neurosci 2000; 12: 147.
25 Owen, AM, McMillan, KM, Laird, AR, Bullmore, E. N-back working memory paradigm: a meta-analysis of normative functional neuroimaging studies. Hum Brain Mapp 2005; 25: 4659.
26 Duncan, J, Owen, AM. Common regions of the human frontal lobe recruited by diverse cognitive demands. Trends Neurosci 2000; 23: 475–83.
27 Delbeuck, X, Van der Linden, M, Collette, F. Alzheimer's disease as a disconnection syndrome? Neuropsychol Rev 2003; 13: 7992.
28 Smith, EE, Jonides, J. Neuroimaging analyses of human working memory. Proc Natl Acad Sci U S A 1998; 95: 12061–8.
29 Becker, JT. Working memory and secondary memory deficits in Alzheimer's disease. J Clin Exp Neuropsychol 1988; 10: 739–53.
30 Hodges, JR, Patterson, K. Is semantic memory consistently impaired early in the course of Alzheimer's disease? Neuroanatomical and diagnostic implications. Neuropsychologia 1995; 33: 441–59.
31 Lines, CR, Dawson, C, Preston, GC, Reich, S, Foster, C, Traub, M. Memory and attention in patients with senile dementia of the Alzheimer type and in normal elderly subjects. J Clin Exp Neuropsychol 1991; 13: 691702.
32 Perry, RJ, Watson, P, Hodges, JR. The nature and staging of attention dysfunction in early (minimal and mild) Alzheimer's disease: relationship to episodic and semantic memory impairment. Neuropsychologia 2000; 38: 252–71.
33 Traykov, L, Raoux, N, Latour, F, Gallo, L, Hanon, O, Baudic, S, et al. Executive functions deficit in mild cognitive impairment. Cogn Behav Neurol 2007; 20: 219–24.
34 Baddeley, AD, Hitch, GJ. Working memory. In The Psychology of Learning and Motivation: Advances in Research and Theory (ed Bower, GH): 4889. Academic Press, 1974.
35 Collette, F, Van der Linden, M, Bechet, S, Salmon, E. Phonological loop and central executive functioning in Alzheimer's disease. Neuropsychologia 1999; 37: 905–18.
36 Owen, AM, Hampshire, A, Grahn, JA, Stenton, R, Dajani, S, Burns, AS, et al. Putting brain training to the test. Nature 2010; 465: 775–8.
37 Willis, SL, Tennstedt, SL, Marsiske, M, Ball, K, Elias, J, Koepke, KM, et al. Long-term effects of cognitive training on everyday functional outcomes in older adults. JAMA 2006; 296: 2805–14.
38 Bier, N, van der Linden, M, Gagnon, L, Desrosiers, J, Adam, S, Louveaux, S, et al. Face-name association learning in early Alzheimer's disease: a comparison of learning methods and their underlying mechanisms. Neuropsychol Rehabil 2008; 18: 343–71.
39 Belleville, S. Cognitive training for persons with mild cognitive impairment. Int Psychogeriatr 2008; 20: 5766.
40 Sitzer, DI, Twamley, EW, Jeste, DV. Cognitive training in Alzheimer's disease: a meta-analysis of the literature. Acta Psychiatr Scand 2006; 114: 7590.
41 Greene, JD, Baddeley, AD, Hodges, JR. Analysis of the episodic memory deficit in early Alzheimer's disease: evidence from the doors and people test. Neuropsychologia 1996; 34: 537–51.
42 McFarlane, J, Welch, J, Rodgers, J. Severity of Alzheimer's disease and effect on premorbid measures of intelligence. Br J Clin Psychol 2006; 45: 453–63.
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Working memory task performance and chunking in early Alzheimer's disease

  • Jonathan Huntley (a1), Daniel Bor (a2), Adam Hampshire (a3), Adrian Owen (a3) and Robert Howard (a4)...
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