Individual items were averaged for a composite positive and negative mood score. PANAS items were measured 20-min postdose to evaluate participants�� mood near the selleck kinase inhibitor end of each session. The following Visual Analog Scale (VAS) items were assessed: stimulated, jittery, dizzy, drug liking, drug strength, good drug effect, bad drug effect, and urge to smoke. Participants answered each item by placing a vertical mark along a 100-mm line anchored by not at all on the left and extremely on the right. VAS items were measured 5-min postdose to evaluate acute nicotine effects. Heart rate and blood pressure were measured 30 min before and 5 min after each nicotine dose. Data Analysis We assessed baseline performance on the participants�� first experimental session before drug was delivered.
Because there was a significant group difference on CPT baseline performance (nonsmokers made more errors of commission than smokers, p < .05), we used this baseline session as a covariate on subsequent analyses of the CPT. There were two independent variables, group (smokers and nonsmokers) and nicotine dose (0, 0.5, 1.5 mg). The independent variables for the ANT, subjective, and cardiovascular data were group, dose, and trial (predrug vs. postdrug); the RSVP task had a fourth independent variable, T1�CT2 lag positions. Because of missing data on some tasks, analyses were conducted using the Mixed Models procedure in SPSS, which allows for missing data without resorting to imputation. Analysis of RSVP data was conducted using GLM repeated measures in SPSS. Statistical tests were two tailed with alpha = .
05. Post-hoc comparisons between means were conducted using the protected Fisher��s least significant difference test. This procedure was deliberately chosen to avoid the Type II error by minimizing alpha correction. Results At baseline, nonsmokers made a higher percentage of errors of commission compared with smokers, t = 2.21, p < .05; 60.04 (5.22) versus 44.93 (4.44), respectively. Data shown are mean (SE). Nicotine improved performance on the CPT by reducing errors of commission, dose main effect F(2, 108.6) = 4.98, p < .01. Post-hoc tests showed that nonsmokers�� performance was significantly improved following the highest dose of nicotine compared with 0.5 mg, p < .05 and placebo, p < .05. Smokers showed a similar pattern but did not reach significance.
Figure 1 shows that nicotine Cilengitide reduced errors of commission without concomitant reductions in target responses. Figure 1. Effect of nicotine on mean correct target responses and errors of commission on the 6-min Continuous Performance Test in nonsmokers and smokers. Each data point represents the mean (��SE) of the postdose trial (predose trial was a covariate). Significant … On the RSVP, there was a significant group �� trial �� dose interaction for T1 reporting, F(2, 112) = 4.53, p < .