The goal of this study is to determine if a specific experimental brain stimulation technique can be used as a non-invasive way to reduce cigarette cravings in current smokers. This study plans to learn more about the way an experimental technique called "transcranial magnetic stimulation" (TMS) affects a specific part of the brain, called the insula. Some research suggests that this part of the brain plays an important role in craving. The investigators plan to study the effects of TMS using standard surveys and magnetic resonance imaging (MRI) of subjects' brain.