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Abstract:
Abstract: We examined neural correlates of age-related
changes in performance on two highly studied tasks of working
memory (WM; Self Ordered Pointing and N-Back Tasks), each at a
variety of WM loads, to determine if the number of items to be kept
in mind is the determinant of age-related cognitive decline in WM
performance. Older subjects (15M/16F, mean age 84.0) performed
worse than younger subjects on all WM tasks and load conditions
(10M/10F mean age 29.9; all ps < 0.002). Mean differences in
performance were greatest for the highest load condition in the
Self-Ordered Pointing Task and for the lowest load condition in the
N-Back task suggesting that the amount of information to be held in
mind is not the sole component of age-related differences in task
performance. Interestingly, performance in older subjects showed
only selective correlations with age, regional prefrontal volumes,
and among load conditions (both between and within tasks). Thus,
cognitive components other than the number of items to be kept
online contribute to age-related decline in WM performance. The
relationship between WM tasks will be discussed. Supported by NIH
MH11855, NIH AG12611, NIH AG08017 and a VA Merit Grant.
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