Publication Abstract Display | Type: Published Abstract | Title: Diminished verbal fluency is associated with inefficient lexical-semantic switching in HIV-associated neurocognitive disorders. | Authors: Carey CL, Woods SP, Rippeth JD, Conover E, Heaton RK, Grant I, and the HNRC Group | Year: 2004 | Publication: Journal of the International Neuropsychological Society | Volume: 10 Issue: Suppl S1 Pages: 46 | Abstract:Verbal fluency tasks are generally regarded as being sensitive to frontalbasal
ganglia circuit dysfunction such as that associated widt mv infection.
Whereas deficits in verbal fluency are consistendy reported in mvassociated
neurocognitive disorders (HAND), the component cognitive
processes driving these deficits are not known. Accordingly, the present
study investigated several qualitative features of two fluency measures
(i.e.,letter and category fluency) in 25 nondemented individuals with
HAND (i.e., persons with subsyndromic neuropsychological impairment
or minor cognitive/motor disorder) and 37 demographically comparable
,healthy controls (HC). For each task, we calculated the total number of
correct words. average lexical-semantic cluster size, total number of
~Vil.chcs betwct:n CIU8lcrs. and tIlt: pruPOnjOIl of error responses (i.e., intrusions
and perseverations). The HAND group generated fewer correct
words than HC and made significandy fewer switches on both letter (p =
.03) and category fluency (p = .02), but no between-group differences
were evident for average cluster size or errors. Receiver-operating cllaracteristic
curves revealed that switching accurately classified participants
in the HAND and HC groups. These results support the hypothesis dtat
verbal fluency deficits in HAND are associated with inefficient switching
between lexical-semantic clusters, rather than a depletion of the lexicalsemantic
memory stores themselves. These findings alsO deluonatrate the
importance of investigating the qualitative features of neuropsychological
test performance, which can elucidate the cognitive mechanisms of
impairment and enhance clinical detection of HAND. |
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