Prefrontal recruitment mitigates risk taking behavior in HIV infected young adults

Abstract

Background

HIV-infected (HIV+) young adults often engage in risk taking behavior. However, the disruptive effects of HIV on the neurobiological underpinnings of risky decision-making are not well understood.

Methods

Risky decision-making, measured via the Iowa Gambling Task (IGT), was compared voxel-wise to resting cerebral blood flow (rCBF) acquired via arterial spin labeling. Separate topographical maps were obtained for HIV uninfected (HIV–; n=62) and HIV+ (n=41) young adults (18-24 years old) and were compared to the full cohort of participants. For the HIV+ group, rCBF was compared to recent and nadir CD4.

Results

IGT performance was supported by rCBF in three distinct brain regions: Region-I, -II, and -III. The relationship between IGT performance and rCBF in HIV+ individuals was most robust in Region-I, ventromedial prefrontal and insular cortices. Region-II contained strong relationships for both HIV– and HIV+. Region-III, dorsolateral prefrontal and posterior cingulate cortices, contained relationships that were strongest for HIV– controls. IGT performance was intact among HIV+ with higher rCBF in either Region-I or Region-III. By contrast, performance was worse among HIV+ individuals with lower rCBF in both Regions-I, and –III when compared to HIV– controls (p=0.01). rCBF in Region-III was reduced in HIV+ compared to HIV– individuals (p=0.04), and positively associated with nadir CD4 (p=0.02).

Conclusions

Recruitment of executive systems (Region-III) mitigates risk taking behavior in HIV+ and HIV– individuals. Recruitment of reward systems (Region-I) mitigates risk taking behavior when Region-III is disrupted due to immunological compromise. Identifying individual recruitment patterns may aid anatomically directed therapeutics or psychosocial interventions.