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. We completed a single-blind pilot study of 11 individuals with HIV- related mild neurocognitive disorder using a high-interest car racing game with or without tDCS. Results are 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 exploratory/developmental grant application, we seek support to expand our pilot-tested training intervention with 125 individuals (targeting a final n of 90) randomly assigned to an attention control condition, game-based cognitive training with sham tDCS, and cognitive training with active tDCS. We will employ a larger battery of cognitive measures as well as self-report measures of mood, cognitive difficulties, and everyday functioning. We will ask participants to return one month after the post-training assessment to evaluate the persistence of training effects. Demonstration of the effectiveness of this training intervention would provide the basis for a larger and more definitive trial of cognitive training combined with tDCS that would investigate their effects over time and their impact on real world functioning.