Fig. 4. Impact of task modifications on model-based estimates and its association with compulsivity and individual differences.

a Distribution and mean value of model-based scores across (i) transition ratio, (ii) difficulty/order, and (iii) reward drift set. Mean model-based scores were larger when estimated from an 80:20 transition ratio structure compared to 70:30, in easy/1^st play compared to Medium/2^nd play and in those who experienced Drift set B compared to Drift set A. b Model-based associations with compulsivity (CIT) and individual differences (age, gender and education (‘Less Edu’)) across (i) transition ratio, (ii) difficulty/order, and (iii) reward drift set. The association between greater self-report compulsivity and MBI was greater when estimated from 70:30 transition ratio structure and using drift set A. Error bars reflect standard errors of the mean. *p < 0.05; **p < 0.01; p < 0.001***.