(A) Sleep efficiency and (B) sleep fragmentation at baseline, methamphetamine self-administration maintenance (0.01 mg/kg/infusion), extinction, or reinstatement test sessions conducted with three different doses of methamphetamine (METH, 0.03, 0.1 or 0.3 mg/kg, IV). Nighttime activity data for baseline and self-administration maintenance were combined across a 5-day span of time. Nighttime activity data for extinction were recorded as the night after the first effective extinction session. Data are expressed as mean±SEM. *p<0.05 compared to Maintenance (0.01 METH); Δ p<0.05 compared to Extinction(Saline). One-way repeated measures ANOVA followed by Bonferroni’s post-hoc test.