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Abstract:
Hippocampal atrophy (HA) occurs in normal aging. Hippocampal
volume reduction in cognitively normal elderly participants
correlates with development of Alzheimer's dementia (AD). HA
measurement is, therefore, an important tool for assessing risk of
developing AD. However, this measurement requires quantitative
analysis of neuroimages, a costly and time-consuming procedure. HA
is also correlated with cognitive impairments and memory
dysfunction, suggesting the promise of behavioral markers of HA. We
considered a battery of behavioral tasks in humans: (1)
feature-irrelevant transfer, (2) learned irrelevance, and (3)
acquired equivalence. The battery was administered to non-demented
adults presenting at the New York University Silberstein Aging and
Dementia Research Center with complaints of subjective memory
disturbance. On all tasks, individuals with and without HA were
expected to show similar performance on the simple learning
component, whereas only HA participants were expected to perform
poorly o n a transfer component. Performance was compared to
presence or absence of at least unilateral HA as judged by a blind
rater. We predicted that performance on our computerized tasks
would be a better indication of HA than delayed paragraph recall.
This study supports the development of a battery of easily
administered behavioral tasks to be used as a screen for patients
at risk for HA and AD.
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