Lee, Malson, Waters, Moolchan, and Pickworth (2003) examined the reliability of objective smoking topography measures during the ad lib smoking of a single cigarette of one��s own brand on four different done occasions, finding high reliability for puff volume, duration, and velocity. Although these results suggest that topography measures from a single cigarette are reliable across several occasions, this study examined only seven highly dependent smokers, all but one of whom were Black. Little research has examined the reliability of subjective responses to smoking a cigarette, although other research has shown high reliability of subjective responses to fixed doses of nicotine nasal spray across days (Perkins, Jetton, Stolinski, Fonte, & Conklin, 2003). Following up results of Shahab et al.

and Lee et al., we examined the reliability of puff topography measures during the ad lib smoking of one cigarette of one��s own brand on four different occasions. We expanded the assessment of reliability to subjective reward (liking) and perception (how strong) of the cigarette. We assessed a sample of nearly 100 smokers to increase confidence in the reliability results and to allow some examination of characteristics that might relate to differences in reliability of responses. For example, puff topography may be more reliable among highly dependent smokers, whose smoking behavior may be more invariant and automatic (e.g., Shiffman & Paty, 2006). Secondarily, we also examined individual differences in the absolute magnitude of responses based on sex and dependence level.

Methods Participants Participants (n = 94; 55 male and 39 female) were adult smokers (��10 cigarettes/day) recruited via ads posted in the surrounding community for a study examining the relationship between negative mood induction and smoking responses (see Perkins, Karelitz, Conklin, Sayette, & Giedgowd, 2010). Ethnic representation was 83% Caucasian, 16% Black, and 1% Hispanic. Mean �� SE sample characteristics were age of 26.8 �� 1.0 years, nicotine yield of preferred brand of 1.04 �� 0.02 mg, daily smoking rate of 19.5 �� 0.6 cigarettes/day for 10.6 �� 0.9 years, and Fagerstr?m Test for Nicotine Dependence (FTND; Heatherton, Kozlowski, Frecker, & Fagerstrom, 1991) score of 4.7 �� 0.2, indicating moderate dependence. Men and women did not differ on any of these characteristics.

Procedure The larger study involved five sessions, but one session did not involve ad lib smoking upon arrival, and so, only smoking topography data from the other four sessions are examined here. A mean of 2.8 �� 0.1 days separated sessions, and sessions were scheduled for the same time of day (��1 hr) within GSK-3 subjects. Participants were instructed to smoke ad libitum prior to arriving for each session.