Functional Brain Connectivity, Peer Influence, and Risky Behavior

Temple University, Philadelphia PA

Investigators

Abstract

The Directorate of Social, Behavioral and Economic Sciences offers postdoctoral research fellowships to provide opportunities for recent doctoral graduates to obtain additional training, to gain research experience under the sponsorship of established scientists, and to broaden their scientific horizons beyond their undergraduate and graduate training. Postdoctoral fellowships are further designed to assist new scientists to direct their research efforts across traditional disciplinary lines and to avail themselves of unique research resources, sites, and facilities, including at foreign locations. This postdoctoral fellowship award supports a rising scholar investigating risky behavior in adolescents, using interdisciplinary approaches drawn from neuroscience, cognitive science and developmental psychology. Adolescent risk-taking is a significant threat to public health, and contributes to a variety of adverse outcomes, including drug and alcohol abuse, teen pregnancy and STIs, and violent crime. Two elements are known to contribute significantly to likelihood to engage in risk-taking: first, youth are more likely to take risks in the presence of peers, and second, risk-taking increases when youth are under the influence of alcohol. While alcohol consumption often takes place in a social setting, little research has considered how alcohol use and peer presence interact to influence adolescent decision-making. The present study uses a neurobiological framework to examine how the combination of peer presence and alcohol consumption affects brain responses during risk-taking tasks. Specifically, the project examines how peer presence and alcohol affect connections between brain areas known to be involved in risky decision-making. The project also examines how individual differences in brain responses relate to individual tendency to engage in risk-taking, give in to peer pressure, and abuse drugs and alcohol. Ultimately, the goal of this project is to develop a more sophisticated understanding of the mechanisms underlying suboptimal decision-making in adolescence, and to identify potential neural or behavioral factors that predispose some youth to greater risk. Adolescence is a time of considerable brain development, and a significant body of research suggests that two neural systems mature along different trajectories throughout this period. The differing developmental time courses of 1) cognitive control and 2) affective/reward processing are thought to contribute to adolescents' tendency to engage in risk-taking. The neural regions involved in these processes are well-characterized in the literature. However, much less is known about the way these regions interact during development, and how this interaction is affected by contextual factors that impact risk-taking. Previous research has identified two contextual factors that contribute significantly to adolescents? likelihood to engage in risky decision-making: first, adolescents are more likely to take risks in the presence of peers, and second, risk-taking increases when youth are under the influence of alcohol. While alcohol consumption in adolescence often takes place in a social setting, little research has considered how alcohol use and peer presence interact to influence decision-making. The present project addresses the limitations in the current literature by 1) utilizing fMRI analytic techniques that test models of interaction between multiple neural systems and 2) investigating the combined role of peer presence and alcohol intoxication on adolescent decision-making in a single experimental design. This project tests the hypothesis that peer presence and alcohol intoxication significantly diminish connectivity between cognitive control and affective processing regions during decision-making, thereby contributing to increased risk-taking. The project will also examine how neural responses relate to individual tendency to take risks and give in to peer pressure. In the field of developmental cognitive neuroscience, the predominant theories of adolescent decision-making posit a causal relationship between brain activity in multiple neural systems during risk-taking. However, the extant literature has relied on analytic approaches that are not designed to test causal interactions between brain regions. This project utilizes fMRI analytic approaches that test functional and effective connectivity between regions (Psychophysiological Interaction and Dynamic Causal Modeling), in order to directly investigate the way these regions interact and the direction of effects. Furthermore, this project will shed light on the combined role of peers and alcohol during risky decision-making, leading to a more sophisticated understanding of the way biological and sociocultural factors interact to produce outcomes in adolescence. The project and postdoctoral training require an interdisciplinary approach, utilizing analytic techniques from cognitive neuroscience, theories from developmental psychology, and experimental methods drawn from both clinical psychology and functional neuroimaging.