PROJECT SUMMARY This is a resubmission in response to RFA-OD-15-004. It responds to priority areas #4 (e-cigarettes), #6 (characterizing flavors), and #9 (consumer perceptions) in this RFA. Surveillance data document a high prevalence of flavored tobacco product (FTP) use among youth and young adults (~18%) relative to any other age group.1-4 Flavors have been hypothesized to mask the harshness of tobacco, making it easier for new users to initiate. The fruity, chocolatey, or minty flavors of FTPs also contribute to the perception that FTPs are safer and less harmful and addictive than non-FTPs,5,6 all of which enhance their appeal and attractiveness, increase curiosity, and facilitate experimentation with tobacco products. Experimentation with FTPs has been linked to progression to regular tobacco use and nicotine dependence in youth and young adults (YAs-defined as ages 18-24).7-11 Although the FDA has banned flavored cigarettes, products like menthol cigarettes, as well as flavored cigars, little cigars/cigarillos, e- cigarettes, and hookah are not banned. Timely research is needed to determine the impact of FTP characteristics, such as appeal, on curiosity, initiation, and use behavior in vulnerable groups, including YAs, so that regulatory actions can be empirically informed and appropriately targeted to maximize population health. The limitation of current measurements of tobacco product appeal is that appeal likely occurs implicitly - below conscious awareness - given potential dissonance between the known harms of these products, social norms surrounding their use, and the appeal of product marketing and packaging, including flavors.6 Drawing on the Dual Process Model of Addiction, this study uses a multi-method laboratory and longitudinal design to develop new methods for quantifying FTP appeal and abuse liability that address these limitations and will inform FDA regulation of tobacco products. We will recruit young adult (YA) current tobacco users (n = 60) and susceptible (never) users (n = 60) and measure baseline implicit appeal for FTPs and non-FTPs and the impact of appeal on changes in tobacco use behavior and attitudes over 6-months using monthly web-based assessments. Implicit appeal will be assessed via two laboratory tasks: an Implicit Association Task (IAT) that measures the speed with which participants accurately pair pictures of FTPs vs non-FTPs with words related to ?attractive? or ?unattractive?, and a behavioral economic purchase task designed to assess demand for FTPs vs non-FTPs under escalating price conditions. If implicit FTP appeal is higher than non-FTP appeal, especially among susceptible never users, and if FTP appeal negatively influences tobacco use outcomes and attitudes, this suggests that FTPs are a public health hazard. Results can inform potential FDA regulatory decisions about FTPs, including applying the flavored cigarette ban to other tobacco products, restricting the sale of FTPs to adult-only venues, and developing anti-tobacco public health campaigns to reduce appeal of FTPs. Findings will help the PI establish an independent career in tobacco regulatory research and will provide preliminary data for an R01 of tobacco product appeal that will inform FDA?s regulation of tobacco products to protect public health.