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Abstract:
Abstract: Many studies have demonstrated an age-related
decrease in performance during a working memory task. Age-related
changes in allocation of cognitive resources have been proposed as
an explanation. The goal of our research was to determine whether
older people must allocate more resources than younger people to
perform a task with high demands on the central executive. We used
a working memory task that required participants to update and
manipulate verbal items in memory, an evident function of the
central executive. These types of operations engage frontal lobe
processing, a region of the brain whose functions are thought to
deteriorate in the elderly. A task irrelevant auditory probe was
used to obtain the event-related potential (ERP) response. The peak
amplitude from the N100 (N1) component in response to the probe,
measured at the frontal midline site (Fz), was used as an index of
resource allocation. The results showed a significant decrease in
the N1 amplitude for older participants (but not for younger
participants) during the updating portion of the working memory
task, in comparison to a control task with minimal mental load.
This finding supports the hypothesis that older people must
allocate more available resources to a primary task when the
central executive must coordinate storage and manipulation
functions. Furthermore, it provides evidence that the elderly have
less efficient frontal lobe functioning.
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