Best-fitting parameters for the RL models summarized per experiment and averaged per group.

Each value reported in the column shows mean values for different RL models (left to right: RLε; RL2; RL2b; RLb) and X means that the variable is not used in a model. Significance of the differences is shown on the right of the table: an asterisk in the corresponding column indicates a p value less than 0.05 for a t-test between optimists and pessimists. Parameters ε+, ε− denote the learning rates for positive and negative errors respectively, vo is the initial value of all CS, and τ is the softmax decision parameter.