Figure 7.

Race model approximation to optimal decision-making as stop error penalty is varied. The figure shows the best race parameters, implemented as a diffusion model shown in Figure 2, that approximate the behavior of the optimal model, as the cost of stop errors is changed. The temporal offset to the start of the diffusion process increases (C), and SSRT decreases (D); rate and threshold parameters are unaffected (A, B). Changes in SSRT are similar to those in optimal model and experimental data (Figure 5). Each bar denotes average of 10 simulated “sessions,” each session consisting of 10,000 trials. Error bar = SEM.