The effect of sex on performance during the first three response inhibition training sessions in experiment 2 (n = 38–40/group). Panel A shows sex differences in inhibitory control across the three sessions, collapsed across treatment group. Panel B shows sex differences, collapsed across treatment group, in latency to make a premature (left) or reinforced (right) lever press. Panel C shows sex differences in inhibitory control, collapsed across treatment and session, for each of the premature delay durations. ** p < 0.01, *** p < 0.001 vs males