Fig. 3.

Potential normalized value coding models. Schematic depiction of predicted neuronal responses in the four alternative normalized value coding models. In each panel, four colored lines indicated the model output (y-axis) in each of payoff block (PB1–4) plotted against the expected values of risky option (x-axis). Expected values of safe option were 60, 120, 180 and 240 μl in PB1 to 4, respectively. Model equations are shown in each plot. R_max, β, σ, b and G were free parameters. For this schematic drawing, the following values for free parameters were used; 1. Advanced fractional model, R_max, β and σ were 40 spk s⁻¹, 20 and 10 μl, respectively; 2. Simple fractional model, R_max and b were 40 and 10 spk s⁻¹, respectively; 3. Difference model, G and b were 0.4 (a.u.) and 10 spk s⁻¹, respectively; 4. Range normalization model, R_max and b were 40 and 10 spk s⁻¹, respectively. See Methods for more details