Unilateral lesions of ACC made rats perform worse on STOP-change trials. This is illustrated in Fig. 1E, which shows the average percentage of correct scores for both GO and STOP-change trials. A two-way ANOVA across sessions revealed significant main effects for treatment (F(1,1438) = 1.692, P < 0.0001) and trial type (F(1,1438) = 4.532, P < 0.0001) as well as a significant interaction (F(1,1438) = 0.253, P = 0.0464). To explore this interaction, we performed Bonferroni-corrected pairwise t tests comparing lesions to controls on GO and STOP-change trials. On GO trials, there was no significant difference between controls and lesions (Bonferroni-adjusted: P = 0.1687). We found that both control (Bonferroni-adjusted: P < 0.0001) and lesioned (Bonferroni-adjusted: P < 0.001) rats were worse on STOP-change trials relative to GO trials and that lesioned rats performed significantly worse on STOP-change trials compared to controls (Bonferroni-adjusted: P < 0.0001) (Fig. 1E). Thus, ACC lesions impaired the ability of rats to inhibit and redirect behavior, but left responding on GO trials intact.
