highly significantp < 0.001
ANOVA yielded a highly significant main effect of drug [ F (1, 28) = 36.392, p < 0.001] [mean lever presses per minute (±SEM) AMP + saline group = 13.967 (±1.435); AMP + SCH23390 group = 6.605 (±0.896)] but no effect of intended devaluation or an interaction between these two factors (both F s < 1).