Figure 3.

A, Top, y-axis: mean (±SE) of our estimate of the monkey's accuracy criterion (calculated as the SumLogLR) at DT as a function of DT (in 200 ms bins) during slow (blue) and fast (red) blocks. Bottom, y-axis: distributions of decision time in the slow (blue) and the fast (red) blocks of trials. Insets, Distributions of the reward rate in each block (Eq. 2). B, In the left panels, the data (solid line ±SE) shown in A is compared, separately for each monkey and each block type, with the SumLogLR computed using the best-fit urgency-gating model (dotted line ±SE) with a simple linearly increasing urgency function, shown on the right. Note that the urgency signal that actually scales evidence in the model is a half-wave rectified version of these linear functions. That is, all negative values are set to zero. C, The distributions of decision time and cumulative distributions of success probability at decision time for each of the three trial types, produced by simulating the urgency-gating model using the functions shown in B (compare these results to Fig. 2C).