Figure 1.
A–C, Methamphetamine self-administration training and extinction of drug-reinforced responding for (A) Experiment 1 (n = 24), (B) Experiment 2 (n = 34), and (C) Experiment 3 (n = 37). Left, Methamphetamine self-administration data during training in Context A: number of infusions, active and inactive lever presses (mean ± SEM) over the 12 d of 3 h daily sessions. Right, Extinction data in Context B: number of nonreinforced active and inactive lever presses (mean ± SEM) over the first 12 d of 3 h daily extinction sessions.