3.3. Behavioral results and correlation with EF and neural response at the network-level
Participants rated their cravings based on the Visual Analog Scale (VAS) ranging from 0 to 100 in both active and sham stimulation groups. The linear mixed-effects (LME) analysis revealed a significant effect of time (P < 0.0001), indicating changes in craving scores over time. However, there was no statistically significant effect of group or time × group interaction (Fig A in During the pre-stimulation phase, both the active and sham groups showed a significant increase in craving scores (P uncorrected < 0.0001 for both groups) after the fMRI cue-induced craving task in the first scan (T2 time point in Despite the absence of significant differences between the active and sham groups in terms of craving self-reports, our exploration at the network level revealed significant correlations between electric fields (EFs) and neural responses only in the active group. To further investigate potential relationships between EFs, neural responses, and behavioral outcomes, we examined the correlation between behavioral data (changes in VAS scores) and neural responses or EFs at the network level. However, our analysis did not identify any significant correlations between changes in behavioral data and either frontoparietal PPI connectivity (meth vs. neutral) changes or EFs at the network level. We only found a significant correlation (r = 0.37, p uncorrected = 0.049) between frontoparietal PPI connectivity during meth cue exposure in the pre-stimulation scan (at first scan which can be named baseline) and changes in craving score (VAS changes from T3 to T4 which can be named second cue-induced craving) after active stimulation.