The purpose of this study is to test two quit smoking therapies and to study brain function while each therapy is being used. You will be randomly assigned (like flipping a coin) to one of the two groups. The first therapy is Extinction-Based therapy (EBT). If you are in this group, you will switch to smoking denicotinized cigarettes while wearing a 21 mg/d nicotine patch for one month prior to your quit date. The second therapy is a standard Nicotine Replacement therapy (NRT). If you are in this group, you will smoke your usual brand of cigarettes up to the quit date. Following the quit date, both groups will undergo standard nicotine replacement therapy (21 mg/d for 6 weeks; 14 mg/d for 2 weeks, 7 mg/d for 2 weeks).