External cues and contexts contribute to the development of smoking and the use of other drugs, and drugs themselves can alter the value of conditioned cues. Interestingly, nicotine increases the acquisition of new learning, and has been considered as a "cognitive enhancer". Nicotine also prolongs responding when responding is no longer rewarded, during extinction. Although many studies have examined the effects of drugs on learning (acquisition) and unlearning (extinction) in laboratory animals, few have investigated drug effects on learning in humans. Recently, novel procedures have been developed to study conditioning in humans, pairing initially neutral places with food, money or drugs. The investigators will use one of these procedures, a virtual place conditioning procedure, to study how nicotine affects the acquisition and extinction of conditioned behaviors in humans.
