Figure 11.

Time courses of neuronal and behavioral changes during uncertainty resolution. A, For each of the first, second, and third day of training (Day 1–3), average responses of Type 2 neurons to 100%, 50%, and 0% CSs are shown at the start and end of training (left and center columns). Their responses to well-learned CSs are shown for comparison (right column). *p < 0.05. ns, Not significant. Red square represents the first time when data for the newly learned CSs became statistically not different from data for the well-learned CSs. B, Behavioral changes during choice trials: choice probability of the higher valued CSs (top), target acquisition time during the choice (middle), and the number of saccades before choice (bottom). The behavioral data are shown for choice between 100% and 50% CSs, given the slower changes in neuronal responses between 100% and 50% CSs (A). Error bars indicate SE. C, Neuronal learning expressed as changes in differential responses between the uncertain forced single stimulus (50%) CS trials and the 100% CS trials during Day 1 (first learning session) quantified by ROC (ROCs > 0.5 indicate uncertainty selectivity). Type 2 neuron selectivity is plotted in black. For contrast, we recorded additional Type 1 ADS neurons during the same learning task (shown in red; 3 in Monkey Sm and 5 in Monkey P). As shown in A, Type 2 neurons learned slowly, whereas Type 1 neurons quickly displayed uncertainty preference as shown previously (Monosov and Hikosaka, 2013, their Fig. 5).