I have conducted a number of neuroimaging studies, using both MRI and PET, concerning effects of drugs on brain structure, brain function, and cognition. My neuroimaging studies have focused primarily on chronic and acute effects of marijuana and effects of general anesthesia during early childhood. I currently have an NIH R01 grant (“General Anesthesia During Early Childhood and Brain Development,” # 5R01HD089420-03, 07/01/18 – 03/31/23). One aspect of my experience that is relevant to the proposed study is assessment of reward-related brain activity using the monetary incentive delay task, as well as related psychological characteristics. One of the primary baseline predictors in the proposed study is a measure of reward-related brain activity that I previously found to be sensitive among adolescents who used marijuana frequently. I also used a different modification of this task in a study of healthy adolescents and adults, examining relationships of self-rated impulsivity with reward-related brain activity. Impulsivity and related characteristics are a focus of the proposed study. I have also examined brain activity in chronic marijuana users during performance of a complex, reward-based, monetary decision-making task.