Project IMPACT: Improving Memory Performance by Applying Cognitive Training

Of the 1.2 million Americans living with HIV, over half experience neurocognitive impairments
(NCI) that adversely affect daily living and are predictive of increased morbidity and
mortality. HIV-infected individuals who are addicted to stimulant drugs like cocaine are at
even higher risk for NCI, which contributes to impulsive decision making, and engage in high
rates of risky behaviors that are associated with both poor clinical outcomes and HIV
transmission to others. Delay discounting, a key aspect of impulsivity, describes the
tendency to devalue a reward as the delay to its receipt increases. Individuals addicted to
drugs tend to prefer smaller, immediate rewards over larger, delayed rewards. Excessive
discounting is associated with a wide range of other health risk behaviors, including risky
sex. The Competing Neurobehavioral Decision Systems model posits that excessive discounting
results from greater relative strength of the impulsive system over the executive control
system. The investigators' own work suggests that HIV infection modulates the effect of
cocaine on brain functioning in the executive control network during delay discounting. Prior
research supports a robust association between excessive discounting and working memory
impairment. As a core executive function that supports self-regulation, working memory is
theoretically an intervention target for HIV risk reduction. Computerized working memory
training has been shown to decrease delay discounting in stimulant users, but it has not yet
been tested in HIV-infected drug users. The proposed R21 study will test the preliminary
efficacy of a computerized cognitive training program to improve working memory and reduce
delay discounting in HIV-infected cocaine users. Using a randomized trial design, the
investigators will assign 50 participants to either the experimental cognitive training
condition or an attention-matched control condition. Participants will complete 48 sessions
in 8 weeks, with assessments at baseline, post-training, and 1-month follow-up to evaluate
intervention effects. The investigators hypothesize that cognitive training will, relative to
the control condition, lead to greater improvements in working memory and reductions in delay
discounting. The investigators will also examine change in HIV risk behaviors (cocaine use,
risky sex, and medication adherence). Results will support an R01 application for a larger
scale trial to rigorously test the impact of cognitive training on HIV-related behavioral and
clinical outcomes. This innovative line of research has important translational implications
for HIV clinical practice, including dissemination in resource-limited settings with few
neuropsychology specialists. This proposal directly advances a high priority topic for
AIDS-designated funding by testing a novel treatment for HIV-associated NCI in drug users. By
focusing on a high-risk population that continues to drive HIV transmission, this research
has strong potential to improve neurobehavioral functioning in HIV-infected persons, and
ultimately to reduce the incidence of new HIV infections.

Inclusion Criteria:

- HIV infection

- currently on antiretroviral medications for >3 months

- cocaine use as defined by crack/cocaine use in the past month, cocaine-type stimulant
use disorder, and cocaine as the principal substance of abuse

- working memory impairment as defined by scoring >1 standard deviation below the
normative mean on at least 2 out of the 3 working memory tests

Exclusion Criteria:

- pregnancy

- English non-fluency or illiteracy

- <8th grade education

- serious neurological disorders including HIV dementia, traumatic brain injury, severe
mental illness, or acute psychiatric distress

- impaired mental status

- individuals who state they are planning to move away from the area within the next 3
months

- individuals without stable housing