UCLA

Risk taking underlies many health problems that contribute to the public health burden during the adolescent period. Recent advances in developmental neuroscience have identified key neurobiological underpinnings of adolescent risk taking, but there is little understanding of how these neural processes interact with social processes in order to promote or prevent risk taking. In this dissertation, I use a multi-method, longitudinal program of research, including daily diaries, experimental tasks, and neuroimaging, to examine the mechanisms by which a culturally meaningful type of family relationship - familism - buffers Mexican youth from drug use and risk taking. Familism is a fundamental aspect of family life, which implies children's role in the support and assistance of their family. Results of Study 1 suggest that family obligation values are protective, relating to dampened substance use, largely due to the links with decreased association with deviant peers and increased disclosure to parents. In contrast, family assistance behaviors are a source of risk within high parent-child conflict homes, relating to higher levels of substance use. In study 2, I examine whether familism is protective by influencing neural regions involved in reward processing and cognitive control, neural processes implicated in adolescent risk taking. Results indicate that family obligation values are associated with reduced ventral striatum (VS) activation when receiving monetary rewards and increased prefrontal cortex (PFC) activation when inhibiting behavioral responses. Reduced VS activation correlates with less real-life risk taking behavior and enhanced PFC activation correlates with better decision-making skills. Thus, family obligation may decrease reward sensitivity and enhance cognitive control, thereby reducing adolescent risk taking. In Study 3, I examine whether the meaningful and rewarding nature of family assistance may be an asset for adolescents. Results show that enhanced VS activation when contributing to the family predicts decreases in adolescents' risk taking behavior over the next year. Thus, family relationships that are personally meaningful can provide adolescents with a sense of reward, and this reward may lead to positive, healthy outcomes. Results of this dissertation indicate that traditional family values and practices play a critical role in shaping Mexican adolescents' risk for substance use and risk taking.