Centre for Policy on Ageing



Effects of Alzheimer's disease on visual enumeration
Author(s)	Elizabeth A Maylor, Derrick G Watson, Zoe Muller
Journal title	Journals of Gerontology: Series B, Psychological Sciences and Social Sciences, vol 60B, no 3, May 2005
Pages	pp P129-P135
Source	http://www.geron.org
Keywords	Dementia ; Mental speed ; Performance.
Annotation	Speeded enumeration of visual objects typically produces fast and accurate performance for up to 3 to 4 items (subitisation), but slower and less accurate performance when counting more items. The authors investigated enumeration ability in patients with Alzheimer's disease (AD) and in age-matched controls. AD patients were slower overall than controls. The subitising span was significantly reduced for patients with AD compared with controls (2.3 vs 3.5 items) and counting rate was significantly slower (451 vs 349 ms/item). Error rates were similar in the two groups except numerosity 3, when AD patients made errors but controls did not (consistent with their subitising spans). Within the AD group, several aspects of performance correlated significantly with Mini Mental State Examination (MMSE) scores. Together, the results provide a striking contrast with studies showing preservation of enumeration ability in normal ageing. (RH).
Accession Number	CPA-051103216 A
Classmark	EA: DG: 5H
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...from the Ageinfo database published by Centre for Policy on Ageing.