Journals of Gerontology Series B: Psychological Sciences and Social Sciences, Vol 52, Issue 5 P206-P215, Copyright © 1997 by The Gerontological Society of America
A multinomial modeling analysis of memory deficits in Alzheimer's disease and vascular dementia
WH Batchelder, J Chosak-Reiter, WR Shankle and MB Dick
Department of Cognitive Sciences, University of California, Irvine, USA. [email protected]
Data from the immediate recall task of the Consortium to Establish a
Registry for Alzheimer's Disease neuropsychological test battery were
disaggregated into nine subject groups and analyzed with traditional
statistics as well as with a general processing tree (GPT) model of free
recall. The groups represented four levels of severity of Alzheimer's and
vascular dementia, as well as a ninth group of healthy elderly controls. It
was demonstrated that the patterns of success and failure of recall to
individual items across successive trials contained much more information
than the marginal trial-to-trial performance scores traditionally used in
scoring the test. The GPT model analyzed recall performance in terms of
three levels of item storage: unstored, intermediate, and long-term.
Associated with the intermediate and long-term storage levels were
respective retrieval parameters. Statistical methods enable one to estimate
the parameters for each group, and the analyses revealed group differences
in long- term storage that were not evident in a statistical analysis of
the marginal trial-to-trial performance scores.
