Figure 2.

Behavioral data from three sample patients with similar cumulative behavior (each chose high effort on 60–64% of trials). On the left, participant’s observed choices (hard or easy) are plotted by reward value. On the right, observed choices are overlaid with model-predicted probabilities of choosing high effort for 88% probability trials from the SV model, 50% probability trials from the SV model, and bias model (all probabilities). The participant best-fit by the full-SV model (top) chooses high-effort more frequently as reward increases, with different rates for 88% and 50% probability trials. The participant best-fit by the reward-only SV model shows similar effects of reward, but with little effect of probability (note that the lines for 88% and 50% probability conditions exhibit complete overlap). The bottom panel represents data from a patient best-fit by the bias model, where the percentage of high effort choices does not increase as reward increases and choices show little effect of probability.