*3.1. Comparison of the IGT Measures between the Groups*

Table 1 contains the results obtained in the mixed ANOVA (adjusted by age and education) comparing the proficiency in the IGT between the groups (see also the first panel in Figure 1). The interaction of the within- and between-subjects factors was statistically significant (*F* = 4.09, *p* < 0.001, η<sup>2</sup> = 0.019), indicating that the learning curves had a specific shape depending on the group. No statistically significant differences between the blocks were found among patients in the bad outcome group (*F* = 1.63, *p* = 0.166, η<sup>2</sup> = 0.015), suggesting the absence of a learning curve. Within patients with a good outcome, significant linear (*F* = 23.3, *p* < 0.001, η<sup>2</sup> = 0.124) and quadratic (*F* = 6.49, *p* = 0.012, η<sup>2</sup> = 0.038) trends appeared: increasing means with blocks were registered (from −2.4 in block 1 to 1.2 in block 5), the difference being lower comparing blocks 4 versus 5 (1.23 versus 1.21). The same pattern was obtained in the control group: significant linear (*F* = 79.71, *p* < 0.001, η<sup>2</sup> = 0.296) and quadratic (*F* = 27.99, *p* < 0.001, η<sup>2</sup> = 0.128) trends.

**Table 1.** Performance learning curves in the Iowa Gambling Task (2 × 5 ANOVA adjusted by age and education).


Note. SD: standard deviation; \* Bold: significant comparison (0.05 level); η2: partial eta-squared.

**Figure 1.** Iowa Gambling Task (IGT) performance–learning curves (**left**) and IGT global scores by group (**right**). Note. Sample size *n* = 424. SE: standard error.

Table 2 contains the results of the ANCOVA (adjusted by age and education) comparing the IGT-Learning score between the groups (see the second panel in Figure 1). Statistical differences between the groups appeared (*F* = 7.14, *p* < 0.001, η<sup>2</sup> = 0.124). Pairwise comparisons (contrasts between the groups) also achieved differences between all the groups.


**Table 2.** Comparison of the IGT learning global score: ANCOVA adjusted by age and education.

Note. SD: standard deviation; \* Bold: significant comparison (0.05 level); η2: partial eta-squared.
