The episodic buffer and learning in early Alzheimer's disease

Abstract

The role of working memory, specifically the episodic buffer, in the learning performance of patients with very mild (n = 18) and mild (n = 12) Alzheimer's disease as compared with healthy older adults (n = 29) was investigated using a series of word-lists that were manipulated (clustered, unclustered) to explore the impact of strategic organizational skills under varying attention conditions (full, divided). Results indicated that the learning performance for all three groups under full attention was better than that under divided attention, but only for the clustered word-lists. Moreover, in contrast to the mild Alzheimer's disease group, both the healthy older controls and the very mild Alzheimer's disease group demonstrated better performance on clustered word-lists than on unclustered lists, suggesting active strategic organizational skills, even at delayed free recall. The overall pattern of results indicates a staging of working-memory impairment in early Alzheimer's disease.

Carmela Germano was supported by an Australian Postgraduate Award scholarship from the Commonwealth Government of Australia. We gratefully acknowledge the support of the CDAMS clinic teams from Melbourne Extended Care and Rehabilitation Service, Bundoora Extended Care Centre, and Caulfield General Medical Centre as well as the participants involved in this research.