Figure 6.

Model fitting. (A) Trials with variable- (i) and fixed-reward conditions (ii). Results of 2-fold cross validation were compared among the four models: F-C, fixed-choice model; Q: standard Q-learning; FQ: forgetting Q-learning; DFQ: differential forgetting Q-learning. Means and standard errors are shown. The number of free parameters in each model is shown in parentheses: ^**p < 0.01 in a two-sided paired t-test. (B) All trials. FQ-learning and fixed-choice models were employed as learning rules of variable- and fixed-reward conditions, respectively.