Working memory in individuals with HIV infection.

The central executive component (CE) of Baddeley's working memory model (Baddeley, 1992) was evaluated in 26 asymptomatic human immunodeficiency virus-infected individuals (HIV+) and 23 HIV-control subjects using a dual-task working memory paradigm. The HIV+ and HIV- groups showed an equivalent reduction in performance on both the primary task (visual vigilance) and the secondary task (letter span) when they were performed concurrently relative to when either task was performed alone. This result suggested normal CE functioning in these HIV+ subjects. In contrast, the HIV+ subjects had significantly longer response latencies on reaction time measures relative to the HIV- control group. These findings indicated that slowed processing in early stage HIV-infected individuals is not associated with a working memory deficit.