A new test of strategy application was designed
to be relatively free of the constraints that limit the
standard neuropsychological assessment of supervisory abilities.
The validity of the test was assessed in 3 samples of participants
with varying degrees of supervisory deficits and frontal
systems dysfunction: focal frontal lesions, traumatic brain
injury (TBI), and normal aging. Inefficient strategy application
varied systematically across the 3 groups and was not due
to extraneous factors such as forgetting the test instructions.
Previous case studies have emphasized strategy application
deficits in the face of normal neuropsychological test
performance. In this study, it was shown that strategically
impaired participants from a consecutive series can include
those both with and without deficient neuropsychological
test performance. When neuropsychological impairment was
present, it was greatest on executive functioning tasks.
Among participants with nonstrategic performance, there
was evidence for a dissociation of knowledge from action.
This finding was not specific to focal frontal lesions.
A number of supervisory processes contributing to strategy
application were identified. Exploratory analyses indicated
differential effects of lesion location on these processes,
especially inferior medial frontal and right hemisphere
lesions. Overall, the results supported the use of unstructured
tasks in the assessment of supervisory abilities. (JINS,
1998, 4, 247–264.)