ed as a positive reinforcer for humans.In this experiment eight healthy research volunteers, (one female and seven males) were accepted into a 20-day residential study. This means they stayed at the lab, so outside pressures wouldn’t affect their choice to self-administer MA or not. On days 1, 5, 9,13 and 17, at 1000 hours, the research participants were given the “sample” oral dose of methamphetamine. The tablets contained either 0, 5 , or 10 mg of methamphetamine. These tablets were available to the participants for the next 3 days, and they also received an alternate positive reinforcer, which was a $1 voucher (which they could redeem at the end of the study for cash.) Over a 3-day period, the volunteers got to choose (in an 8 trial choice) to take a tablet like they had sampled most recently, or to get one of the $1 vouchers. The participants for this study were recruited through an advertisement in a newspaper in New York City, and also through word of mouth. The group was composed of one female (Hispanic-American,) and seven male (three African-American, three Caucasian, and one Hispanic American) healthy persons aged between 23 to 42 years. When asked to report their drug histories, seven of them reported using cocaine at least once, and three reported using methamphetamine at least once; one reported current cocaine use (4 times a week) and all eight participants reported that they were currently using caffeine, between 2 and 30 cups a week. Data was collected on their participants alcohol use as well their use of tobacco cigarettes, which were available to them. The woman was tested repeatedly to make sure she wasn’t pregnant.The participants were housed in a set-up somewhat similar to that of television’s Big Brother program. They had some private and some public spaces with cameras and microphones in the public spaces only. They had entertainment and they could get food by scanning ba...
