Group parameters of the best-fitting model. GD, gambling disorder; HC, healthy controls. A, C, E, Posterior distribution of group-level parameters per group. B, D, F, Distribution of differences in posterior distributions between groups. Bottom lines indicate the 85% and 95% highest density interval of the distribution. dBF: directed Bayes factor, the proportion of the difference distribution above 0 over the proportion of the difference distribution below 0. A, B, β parameter, which represents random exploration. C, D, φ parameter which represents directed exploration. E, F, ρ parameter which represents perseveration.