Several tests from the CANTAB neuropsychological
test battery previously shown to be sensitive to frontal
lobe dysfunction were administered to a large group of
normal volunteers (N = 341) ranging in age from
21 to 79 years. The main tests included a computerized
form of the Tower of London test of planning, a self-ordered
spatial working memory task, and a test of attentional
set formation and shifting. A computerized form of the
Corsi spatial span task was also given. Age-related graded
declines in performance were seen, sometimes in a discontinuous
manner, especially for the attentional set shifting task
(at the extradimensional shift stage). Patterns of deficits
reminiscent of frontal lobe or basal ganglia damage were
observed in the oldest age group (74–79). However,
overall the data were only partially consistent with the
hypothesis that frontal lobe functions are the most sensitive
to effects of aging. Factor analyses showed that performance
in the executive tests was not simply related to a measure
of fluid intelligence, and their performance had a factor
loading structure distinct from that for the CANTAB tests
of visual memory and learning previously administered to
the same sample. Finally, only limited support was found
for the hypothesis that cognitive aging depends on slowed
information processing. (JINS, 1998, 4,
474–490.)