Matching-to-sample deficits in patients with senile dementias of the Alzheimer and Lewy body types
A. Sahgal, P. H. Galloway, I. G. McKeith, S. Lloyd, J. H. Cook, I. N. Ferrier and J. A. Edwardson
Medical Research Council Neurochemical Pathology Unit, Newcastle General Hospital, Newcastle upon Tyne, England.
Using a computerized matching-to-sample task, nonverbal visual recognition
memory was studied in two groups of patients suffering from senile dementia
of the Alzheimer type or the recently described senile dementia of the Lewy
body type. The patients' cognitive abilities had been shown to be similar
according to a number of standard psychometric tests. The two groups did
not differ with respect to simultaneous matching-to-sample performance,
although both were impaired relative to control. The group with senile
dementia of the Lewy body type was severely impaired, relative to the group
with senile dementia of the Alzheimer type, when delays (delayed matching
to sample) were introduced. The findings suggest that short-term mnemonic
processes, mediated by temporal lobe structures, could be more severely
affected in senile dementia of the Lewy body type.
