Effects of Nicotine on Cognitive Task Performance and Brain Activity as Measured by fMRI

Background: \- Many cigarette smokers claim that smoking improves their ability to think and concentrate, and have reported problems in thinking and concentration after quitting smoking. Some research has indicated that nicotine can enhance certain aspects of attention and memory in humans. However, more research is needed to determine how nicotine affects different elements of the brain s ability to think, pay attention, respond to rewards, and make decisions. Researchers are interested in using functional magnetic resonance imaging (fMRI) to study the effects of nicotine on brain function and activity. Objectives: \- To determine the effects of nicotine on attentional and other thinking processes, including reward-seeking behavior. Eligibility: \- Individuals between 18 and 50 years of age who are either current smokers (10 or more cigarettes per day for at least 1 year) or nonsmokers. Design: * The study has four experiments. Each experiment requires two MRI scanning sessions and a training session. Participant can do one or all of the experiments. * Participants will receive training on the types of computerized tests that will be given during the active portion of the study. Participants will also fill out questionnaires on nicotine use and other alcohol and drug use, and provide breath and urine samples. * During the test sessions, participants will have fMRI scanning while performing up to four different sets of tasks that test attention, memory, concentration, reward-seeking behavior, and decision making. Smokers will wear a nicotine patch or placebo patch during the test sessions, but will not be told which patch they are receiving. The order of these sessions will be different for individual participants. * Participants will provide blood and urine samples throughout the research study for evaluation purposes.