Effects of multiple stressor exposure (stress-exposed rats n = 12, controls n = 12) prior to the two-lever choice tests on lever preference (Experiment 3). Response rates for the lever that delivered valued and devalued outcomes on test days 1 and 2 are shown. On both test days, the outcomes (pellets vs. sucrose) were devaluated in a counterbalanced manner. On day 1, there was a significant effect of devaluation and treatment, but no devaluation × treatment interaction. On day 2, there was a significant effect of devaluation and treatment, and, importantly, a significant devaluation × treatment interaction. Subsequent planned contrasts revealed a significant devaluation effect in controls (P < 0.001), but not in stressed rats (P > 0.05).
