Statistical analyses
Baseline characteristics and the assessment of blinding and sensation questionnaire were analyzed using a t-test or chi-square test.For the number of completions in each PPT subtest, a 2 × 3 mixed-design analysis of variance (ANOVA), with group (active tDCS or sham) as the between-participants factor and time (baseline, online, and offline sessions) as the within- participant factor and effect sizes calculated as partial eta squared (