The above results suggest that ACC contributes to mechanisms that reduce automatic prepotent tendencies to follow the first cue light. Next, we asked whether ACC lesions impacted the frequency of neurons that accurately encoded response direction during conflict adaptation (i.e., sS trials), after presentation of the first cue light, in response to presentation of the second cue light (i.e., STOP signal). We found that for both control and lesioned rats that the distributions of directional indices did not significantly shift above zero on gS trials (control: Wilcoxon, n = 89, µ = 0.027, P = 0.1030; lesion: Wilcoxon, n = 48, µ = 0.027, P = 0.5938) and that there was no difference between groups (Wilcoxon, control: n = 89, µ = 0.027; lesion: n = 48, µ = 0.027, z = −0.3265, P = 0.5360). For sS trials (i.e., conflict adaptation), we found that the distribution of directional indices significantly shifted above zero for control rats only (Fig. 4J; control: Wilcoxon, n = 89, µ = 0.074, P = 0.0262; lesion: Wilcoxon, n = 48, µ = 0.041, P = 0.2954); however, there was no significant difference between controls and lesions (Wilcoxon, z = −0.3265, P = 0.4203).
