Number processing, visuospatial and emotional cognition in asymptomatic individuals with HIV

Human Immunodeficiency Virus (HIV) is an important focus of clinical and cognitive neuroscience research. Multiple studies have implicated frontostriatal dysfunction in HIV and described a profile of cognitive dysfunction with a focus on executive function and memory. By contrast, remarkably little is known about visuospatial and number processing in HIV, though these capacities are also supported by frontostriatal circuits and their parietal connections. The main goal of the present series of studies was to assess the hypothesis that HIV affects numerical and visuospatial processing in early stages of the disease. Standardized and experimental neuropsychological measures were administered to examine functioning in cognitive domains subserved by the areas of the brain supporting numerical and visuospatial processing. The asymptomatic HIV+ group (n=37) was significantly slower and produced more errors on visuospatial and number processing tasks than the HIV- control group (n=37). Both groups showed a significant correlation between number processing and visuospatial performance. These findings demonstrate the impact of HIV on spatial and numerical cognition early in the disease course and provide evidence for the close functional relation between these domains. A second goal was to examine the effect of emotional dysfunction on visuospatial abilities and other aspects of cognition in HIV. In particular, alexithymia, an impairment of affective and cognitive emotional processing, is often associated with HIV and may reflect direct effects of the virus on the prefrontal and anterior cingulate cortices. Accordingly, the hypothesis was that there would be a correlation between extent of alexithymia and cognitive abilities associated with these brain areas, including working memory and executive function, as well as with visuospatial processing because of frontostriatal-parietal interactions. The results revealed that HIV+ participants were significantly more alexithymic than the HIV- group (n=34/group). The extent of alexithymia and its cognitive component, but not depression, correlated with performance on measures of visuospatial and executive function. This examination of visuospatial, numerical and emotional cognition constituted a multidimensional investigation of brain changes associated with HIV. Taken together, the findings expand our understanding of the impact of HIV on visuospatial cognition in the early stage of the disease.