Abstract

L. Chang, O. Speck, E. N. Miller, J. Braun, J. Jovicich, C. Koch, L. Itti, T. Ernst, Neural Correlates of Attention and Working Memory Deficits in HIV Patients, Neurology, Vol. 57, No. 6, pp. 1001-1007, Sep 2001. [1999 impact factor: 5.232] (Cited by 241)

Abstract: Objectives: To evaluate the neural correlates of attention and working memory deficits in patients infected with HIV-1. Method: Functional magnetic resonance imaging (fMRI) was used to evaluate brain activity in 11 HIV-patients and 11 age, gender, education and handedness-matched seronegative subjects, while performing a battery of tasks that required different levels of attention for working memory. Results: HIV-patients showed greater brain activation (BOLD signal changes) in some brain regions compared to control subjects while performing the same tasks. For the simpler tasks, HIV patients showed greater activation in the parietal regions. However, with more difficult tasks, HIV patients showed greater activation additionally in the frontal lobes. Reaction times during these tasks were slower but accuracies were similar in the HIV patients compared to control subjects. Conclusion: Injury to the neural substrate due to the HIV infection may necessitate greater attentional modulation of the neural circuits, hence a greater usage of the brain reserve; additional activation of the frontal lobes is required to perform the more complex tasks. The task-dependent increased frontal activation in the HIV patients suggests that the neural correlate of attentional deficits may be excessive attentional modulation as a result of frontostriatal brain injury.

Themes: Medical Image Processing, Medical Research, Model of Top-Down Attentional Modulation