Adolescence is a time of biological and behavioral changes that can lead to risky and dangerous behaviors, and African-American youth are highly vulnerable to the consequences of risky behavior, including HIV/AIDS and violence, leading to premature death. The investigators previously showed that an intervention program reduces HIV-risk vulnerability behaviors in many African-American youth. The investigators aim to measure how the program affects different regions of the brain in order to better prevent or reduce such risky behaviors among African-American youth.