To determine if directional response selectivity in DMS is dependent on ACC, we unilaterally lesioned ACC and recorded from DMS in the same hemisphere [connections are largely ipsilateral (13)] in rats performing the STOP-change task. We chose unilateral lesions to limit the impact on behavior and to minimize the potential recruitment of redundant systems likely involved in task performance (14). Rats (n = 16) were trained on the directional STOP-change task prior to surgery to ensure that basic task training would be unaffected by ACC lesions. After training, rats received two unilateral, 0.2-µL injections of either ibotenic acid (0.6 M; Tocris; n = 8) or saline into ACC (n = 8, injection 1: anterior–posterior [AP]: +1.2 mm; medial–lateral [ML]: ±0.6 mm; dorsal–ventral [DV]: −2.2 mm; injection 2: AP: +0.2 mm; ML: ±0.6 mm; DV: −2.2 mm) (Fig. 1C). All rats were implanted with eight-channel drivable recording electrodes in DMS (AP: −0.4 mm; ML: ±0.5 mm; DV: −3.5 mm) (Fig. 1C). Rats were randomly assigned to treatment conditions, and no differences in the number of trials performed (t(14) = 0.4149, P
