The analyses included 111 treatment-seeking smokers (52 women) who were recruited using newspaper ads from the Houston metropolitan area and who were paid $125 for attending one screening and four laboratory sessions. Smokers were included if they were willing to quit smoking within 30 days of screening, were between the ages of 18 and 59, smoked 10 or more cigarettes per day, produced an expired carbon monoxide level greater than 8 ppm (or produced saliva cotinine <30 ng/ml), were fluent in English, and had no uncontrolled medical illness. Individuals were excluded if they were taking psychotropic or narcotic medication, met criteria for a current psychiatric disorder, reported hearing loss, or were involved in current smoking-cessation activity.
