Different populations of neurons participated at different time points across the trial (Figure 3D; Figure S5). Many ACC neurons ramped up activity over the 1,000 ms preceding the first step-choice, peaking at choice time and being largely silent following trial outcome. Other neurons were active in the period between choice and outcome, and yet others were active immediately following trial outcome. Individual neurons showed strong tuning to trial events, particularly the choice and second-step state, and to conjunctions of choice and second step or second step and outcome (Figure S5).
