Misperceptions that prevent complete switching to e-cigarettes among adult smokers: A more nuanced communication strategy - PROJECT SUMMARY/ABSTRACT Smoking is the most dangerous way to use nicotine but fewer than 8% of cigarette smokers successfully quit each year. While quitting all tobacco and nicotine use is best, completely switching to a noncombustible nicotine product, like e-cigarettes, can reduce exposure to harmful chemicals and risks for those who cannot quit. However, many people inaccurately believe that e-cigarettes are as harmful as combustible cigarettes, which may suppress switching. Limited research exists on underlying reasons for these beliefs, and few studies have identified educational messages that may be used for adults who smoke to address these beliefs. More research is needed on comprehensive messages that can target beliefs and effectively communicate the relative risks of e-cigarettes versus cigarettes, and to assess their potential effects on beliefs, intentions, and e- cig use. Research is also needed on methodological tools that can be used to identify communication that can effectively increase message-consistent beliefs and behaviors. Extant research suggests that tobacco message testing may be enhanced by using neurocognitive measures of message effectiveness, which have been shown to explain additional variance in intention and behavioral outcomes compared to self-reported measures alone. Functional near-infrared spectroscopy (fNIRS) is one method for measuring neurocognitive response that provides unobtrusive, subconscious, objective measures of cognitive processing predictive of behavior change. The overall aims of the proposed research are to: 1. Identify latent classes of beliefs about cigarette and e-cigarette harms to inform message development; 2. Develop, pilot test, and refine e-cigarette educational messages that target prevalent belief classes using neurocognitive and interview responses, and 3. Test finalized messages to assess effects of belief class messages on neurocognitive response, belief and intention change, and actual e-cigarette use. This study will examine the effectiveness of comprehensive e- cigarette educational messages tailored to prevalent belief patterns, and whether neurocognitive message responses can predict message-consistent beliefs, intentions, and behaviors. A comprehensive training plan is proposed to ensure the implementation of these aims, with objectives focused on 1) refining skills in neuroimaging techniques, experimental design, and analysis, 2) obtaining experience in designing and testing relative risk communications, and 3) expansion of skills in advanced quantitative and qualitative methods. The research and training plans will help me to establish an independent line of research applying communication neuroscience methodology to tobacco regulatory science research, and to support my pathway to independence.