Verbal and spatial working memory performance among HIV-infected adults

Abstract

Subtypes of working memory performance were examined in a cohort of 50 HIV-infected adults and 23 uninfected controls using an n-back paradigm (2-back) in which alphabetic stimuli were quasi-randomly presented to a quadrant of a computer monitor. In the verbal working memory condition, participants determined whether each successive letter matched the letter that appeared two previously in the series, regardless of spatial location. In the spatial working memory condition, participants determined whether each letter matched the spatial location of the letter that had appeared two previously, regardless of letter identity. The dependent variable was percent accuracy in each condition. Results of mixed model ANOVA revealed that the HIV-infected participants performed significantly worse than controls on both the verbal and spatial working memory tasks. A significant main effect for working memory condition was also present with both participant groups performing better on the spatial working memory task. These results, the first study of HIV-infected adults to directly compare verbal versus spatial working memory performance using the identical test stimuli across task conditions, suggests that HIV infection is associated with a decrement in working memory efficiency that is equally apparent for both verbal and spatial processing. These findings implicate central executive dysfunction as a likely substrate and provide the basis for hypothesizing that decline in working memory may contribute to other HIV-associated neuropsychological deficits. (JINS, 2002, 8, 532-538.)

Neuroinflammation in treated HIV-positive individuals

“…28 Increased TSPO binding was associated with poorer cognitive performance on cognitive tasks evaluating verbal learning and memory. Subcorticalfrontal white matter microstructural pathology has been associated previously with impaired performance on verbal learning 29 and memory 30 tests and symptoms of poor attention, problem-solving difficulties, and information retention and recall 31 in Table 3 Correlation PLWH. With our evidence for substantial innate immune activation, we speculate that the relationships we observed between regions with TSPO radioligand uptake and increased MD in white matter may reflect increased inflammation.…”

Processing distinct linguistic information types in working memory in aphasia

“…Previous n-back studies have manipulated stimulus type to tap different types of working memory, such as spatial, visual, auditory, and verbal (e.g., Hinkin et al, 2002;Kubat-Silman, Dagenbach, & Absher, 2002;McEvoy, Smith, & Gevins, 1998). No known study to date has manipulated n-back stimuli to tap different types of linguistic information as we did.…”

Interrater Reliability of Clinical Ratings and Neurocognitive Diagnoses in HIV

“…Approximately 30-50% of persons infected with HIV-1 exhibit neuropsychological (NP) deficits, most notably in cognitive domains related to frontal-subcortical systems (Heaton et al, 1995;Hinkin et al, 2002;Martin et al, 2001). NP impairment is more prevalent and severe in advanced stages of HIV disease (e.g., Basso & Bornstein, 2000;Heaton et al, 1995), and has been associated with CD4 cell counts (e.g., Becker et al, 1997), levels of viral burden in cerebrospinal fluid (CSF; Ellis et al, 2002), incipient dementia (Stern et al, 2001), and postmortem neuropathology (e.g., Cherner et al, 2002;Masliah et al, 1997;Moore et al, 2002).…”