For this randomized double-blind controlled trial, tobacco users will be randomized to use ENDS with an e-liquid containing a neuroactive flavor (hexyl acetate) vs. an inactive flavor (ethyl acetate) for ten days as a supplement to their typical tobacco use. Laboratory measures of ENDS reinforcement, subjective ENDS ratings, and brain reactivity to the flavor using functional magnetic resonance imaging (fMRI) will be collected at baseline and after ten days of ENDS use.
