Cortical and subcortical response to the anticipation of reward in high and average risk-taking adolescents.

Since the first neurodevelopmental models that sought to explain the influx of risky behaviors during adolescence were proposed, there have been a number of revisions, variations and criticisms. Despite providing a strong multi-disciplinary heuristic to explain development of risk behavior, extant models have not isolated reliable neural systems that underlie risk behaviors in adolescence. To address this gap, we screened 2,017 adolescents from an ongoing longitudinal study assessing 15-health risk behaviors, targeting 104 adolescents characterized as high or average in risk-takers. Participants completed the Monetary Incentive Delay (MID) fMRI task, examining reward anticipation to “big win” versus “neutral”. We examined neural response variation associated with both early and longitudinal (multi-wave) risk classifications. Analyses included targeted examination of a priori regions of interest (ROIs), and exploratory non-parametric, whole-brain analyses. Hypothesis-driven ROI analysis revealed no significant differences between high- and average-risk profiles using either early or multi-wave risk classifications. Results of whole-brain analyses differed according to whether risk assessment was based on early assessment or multi-wave data. Despite significant mean-level task activation, results do not replicate prior neural substrates implicated in reward anticipation and adolescent risk taking. Further, these data indicate that whole-brain differences may depend on how risk-behavior profiles are defined.