Ds. Pate et al., DECISION-MAKING AND ATTENTIONAL PROCESSES IN AGING AND IN DEMENTIA OFTHE ALZHEIMERS TYPE, Cognitive neuropsychology, 11(3), 1994, pp. 321-339
Normal young and elderly subjects and patients with very mild or mild
dementia of the Alzheimer's type performed several reaction-time (RT)
tasks tapping basic cognitive components of attentional and decision-m
aking processes. The results of Experiment 1 suggested that processes
common to Simple and Choice RT tasks were slowed with ageing but were
not affected by Alzheimer's disease (AD) until dementia severity reach
ed a mild degree. In contrast, decision-making processes were slowed b
y AD even in the very mildly demented patients. The results of Experim
ent 2 indicated that all groups benefitted from a warning signal, but
the time course of increasing alertness varied across groups. Comparis
on of these experiments with the literature and with each other sugges
ts that very mild AD subjects are abnormally dependent on the presence
of a warning signal and, more speculatively, that the informative as
well as alerting aspects of such signals play a critical role.