Figure 7.

(a) For the single-stage model μ₁ = 0.2, σ₁ = 0.1 and x₀ = 0, while for the two-stage model μ₁ = 0.1, μ₂ = 0.5, σ₁ = σ₂ = 0.1, x₀ = 0 and t₁ = 0.15. The non-decision time T_nd = 0.3. The reward rate for the single-stage model is a unimodal function and achieves a unique local maximum, while the reward rate for the two-stage model has two local maxima. (b) Optimal threshold for two-stage model obtained by maximizing reward rate. The left panel shows the variation of the optimal threshold as a function of t₁ and μ₁. The other parameters are μ₂ = 0.5, σ₁ = σ₂ = 0.1, and x₀ = 0. The regions of the contour plot associated with t₁ = 0 and μ₁ = 0.5 correspond to the single-stage model.