Smokers were recruited from the Houston metropolitan area using newspaper advertisements and flyers. They were paid $125 for attending 4 laboratory sessions and an additional five dollars each session for arriving promptly. Smokers who were between the ages of 18 and 59, fluent in English, smoked 10 or more cigarettes per day, had an expired carbon monoxide level greater than 8 ppm (or saliva cotinine >30 ng/ml), and reported no uncontrolled medical illness were included in the study. Individuals were excluded if they were taking psychotropic or narcotic medication, met criteria for a current psychiatric disorder, reported hearing loss, were using tobacco products other than cigarettes, or were involved in current smoking cessation activity. Smokers were not recruited based on their interest in quitting and no cessation treatment was provided. A total of 113 participants contributed to the main study (Cinciripini et al., 2006). A sub-sample of 84 individuals, restricted to African American and Caucasians smokers, provided genotypic data for the current analyses.
