| Abstract:Although HIV-1 infection is associated with cognitive impairment in domains mediated by frontal-basal ganglia circuits, conventional measures of verbal fluency (e.g., category fluency) have shown surprisingly unreliable sensitivity to HIV disease. However, action (verb) fluency - a verbal fluency task requiring the spontaneous generation of verbs - has not previously been examined in an HIV-infected sample. The action fluency task evolved from literature indicating that object naming is principally mediated by left temporal-parietal networks, whereas verb naming is primarily associated with left frontal-basal ganglia circuits. Consistent with this premise, studies in Parkinson`s disease indicate that action fluency is more sensitive to frontal-basal ganglia pathophysiology than lexical and semantic fluency. The present study examined action, letter (f), and category (animals) verbal fluency in 20 healthy controls (HC) and 100 persons with HIV-1 infection who were comparable in demographics, handedness, and estimated verbal IQ. The HIV+ group performed significantly worse on action fluency (p <= .01, d = -.57); however, there was no significant difference for animal fluency (p > .10) and only a trend for the HIV+ group to perform worse on letter fluency (p = .08). Findings indicate that persons infected with HIV-1 experience greatest difficulty in rapidly retrieving verbs from semantic memory, which is consistent with research indicating that HIV-1 disease is associated with deficits in processing speed and retrieval strategies mediated by frontal-basal ganglia circuits. Data also provide further support for the construct validity of action fluency as a putative measure of frontal-basal ganglia circuit functions. |