Theoretical models of addiction propose that the transition to substance dependence is marked by a shift in motivational drivers of use: from positive reinforcement use motives (e.g., experiencing pleasurable sensations, improved concentration, or social bonding) to negative reinforcement use motives (e.g., relief from stress, boredom, or physical discomfort). By capturing acute motivational states that precede vaping events within individuals' real-world environments, both in early and later stages of e-cigarette use, it is possible to empirically assess this theory. Furthermore, integrating these data with measures of brain activity in key neural systems involved in reward, stress regulation, and interoception may yield a deeper understanding of the dynamic and multifaceted drivers of e-cigarette use across the trajectory of use escalation.

Adolescence is a period of social development marked by increased sensitivity to social feedback and substance use experimentation. Reinforcement learning models offer a powerful framework to examine how adolescents learn from social experiences and how these processes relate to real-world behaviors. This research seeks to explore the following questions:

Does neural tracking of social learning signals during adolescence determine associations between friend group substance use and use curiosity?

Do developmental changes in habenula responsivity to social reinforcement longitudinally predict adolescents’ substance use?

This project examines how acute changes in digital media use impact other reward seeking and self-soothing behaviors. As digital media delivers a consistent stream of rewarding stimuli, heavy use has the potential to dysregulate neurobiological, reward processing systems implicated in drug use. This project is interested in addressing the following questions:

Can acute digital media inaccessibility induce craving for other incentive-driven behaviors like substance use?

Are substances used to relieve distress evoked by media or restricted media access?

Can differential brain function associated with disruptive digital media use lead to other psychopathology?

Developmental changes in dopaminergic functioning may be involved in substance use initiation and escalation during adolescence. Basal ganglia tissue iron estimates can be used as a noninvasive, indirect measure of dopamine-related neurophysiology. This project aimed to examine the following questions:

Do adolescents with diminished age-related increases in basal ganglia tissue iron have a greater propensity toward substance use?

Do these same individuals also require greater incentive-driven motivation to reach the same cognitive control performance as their peers?

Overall, results may suggest a shared developmental neurophysiological phenotype underlying different incentive-driven behaviors during adolescence.