180 young adult current vapers will be recruited from multiple sources including the University of Georgia (UGA) student research pools from the Communication, Psychology, and Sociology Departments, posters, yard signs, local community liaisons, and via Craigslist and social media ads. The screening will begin with a brief online survey. The link to the survey will be included in the research pool websites, flyers, and social media ads. Those eligible after the screening will be invited to interview via Zoom for a more detailed assessment of eligibility. Eligible participants will be sent a pre-scan survey (about 0.5 hours) 24 hours prior to the in-person lab visit. They will then be invited to a 1.5-hour visit to UGA's Bioimaging Research Center (BIRC) and instructed to vape, or not, as usual that day. Upon arrival, participants' eligibility will be confirmed, and written informed consent will be obtained. Breath and urine samples will be collected to biochemically confirm the level of nicotine exposure (i.e., tobacco use severity), followed by the remaining pre-scan measures. Participants will then be trained to perform the fMRI tasks. During fMRI, they will wear earplugs and MR-compatible vision correction, if needed, and lie on the scanner table. Stimuli will be back-projected, and responses collected using a four-button response box configured to allow on-screen Likert scale ratings of 1-7, both via Eprime 3.0 software. MRI will last approximately 60min, followed by post-scan measures (about 0.5 hours).

After the baseline fMRI scan, investigators will deliver static, visual, and textual anti-vaping public service announcements (PSAs) and assess participants' evaluations of the PSAs weekly through brief online surveys via e-mails and text messages. In the two PSA conditions, every week participants will receive an email and a text message through which a static visual anti-vaping PSA will be displayed to them before a query to evaluate the perceived effectiveness of the PSAs, followed by questions about their tobacco use status during the past week. Half of the PSA condition participants (n=60) will be exposed to regular PSAs that focus generally on the negative consequences of vaping, and the other half (n=60) will be exposed to flavor PSAs, which focus specifically on the harms and negative consequences associated with vaping flavored e-cigarettes. Flavor PSAs will be both drawn from existing regular PSAs and created by adding a flavor theme on regular PSAs because existing flavor PSAs are still rare. PSA condition participants will switch types of PSA exposure after 6 months. Each week a different PSA will be displayed to the participants. Therefore, half of the PSA condition participants will be exposed to 24 regular PSAs during the first 6 months, and then to 24 flavor PSAs during the second 6 months. For the other half of the PSA condition participants, they will also be displayed the same 48 PSAs, but in the reverse sequence, i.e., 24 flavor PSAs first, then 24 regular PSAs next. Participants in the control condition (n=60) will directly answer the survey questions about their tobacco use status during the past week without PSA exposure and evaluation.

At 3-, 6-, 9- and 12-months participants will complete a 15-min visit that includes a CO confirmation for smoking, a urinary cotinine test for nicotine use, and other in-person follow-up measures.