Computer Training and Transcranial Direct Current Stimulation for Cognition in HIV

In spite of advances in its treatment, persons with HIV continue to develop HIV-associated neurocognitive disorders (HAND) over time. HAND may be an even more significant problem in older persons (age 50+) with HIV who may experience age-related changes in cognition in addition to HAND. Because of HAND's impact on patients' functioning and quality of life, treatments are needed. Pharmacologic treatments have, in general, been ineffective and investigators have argued that computer delivered cognitive training may be an effective alternative. While results of small studies have been encouraging, the effect size of cognitive training may be small and of unclear practical importance. The nature of cognitive training programs, often building on laboratory measures of cognition, may reduce how inherently interesting (i.e., fun) they are, limiting their uptake outside of paid research studies. Others have argued for the use of computer games targeting psychomotor speed, problem solving, and visuospatial skills to improve cognitive function in older adults. Data support the utility of this approach, but again effect sizes may be small.

Transcranial direct current stimulation (tDCS) may be an effective way to enhance the effects of cognitive training. It involves the application of a small electric current (1-2 mA) to the head, inducing small currents within the brain that enhance cognitive training. Multiple studies have shown that tDCS enhances cognition, including attention and psychomotor speed. The investigators previously completed a single-blind pilot study of individuals with HIV-related mild neurocognitive disorder using a high-interest car racing game with or without tDCS. Results were encouraging in showing moderate to large effect sizes consistent with tDCS enhancement of cognitive function after six 20-minute training sessions over two weeks. Participants' subjective reports of cognitive difficulties supported observed effects on objective measures, and their mood improved. The intervention was acceptable to participants, many of whom stated they enjoyed it. Everyone indicated a willingness to participate in a similar study in the future.

In this study the investigators will expand on a pilot-tested training intervention with 120 individuals randomly assigned to an attention control condition or game-based cognitive training with either sham or active tDCS. The investigators will employ a battery of cognitive measures as well as self-report measures of mood, cognitive difficulties, and everyday functioning in order to evaluate the effects of study interventions.

Participants will first be screened for eligibility by telephone, and then scheduled for a visit during which their eligibility will be further assessed. Those who are eligible based on inclusion and exclusion criteria will complete a battery of measures of their cognitive and functional status. They will then complete six training sessions over a period of three weeks, and then once again complete the battery of assessments. Participants will then be asked to return one month after the post-training assessment to evaluate the persistence of training effects.