Correlations among the significant variables that were identified by the RF classification model revealed three highly significant positive associations among the FC features (L.Cdt–R.Pal with L.Cdt–L.Tha; L.Tha–R.Tha with L.Tha–R.Ptm; and R.Ins–R.ACC with R.ACC–R.PCC), and each of these significant pairs had a common node, i.e., L.Cdt, L.Tha, and R.ACC, respectively. While it is expected that the pairs with a common node would correlate with each other, they are also known to be structurally connected. For instance, while the caudate nucleus connects the pallidum with radial fibers [122], these basal ganglia structures have reciprocal connections with the thalamus and cortical regions and, thus, mediate cognitive and motor functions [123]. Similarly, while the ACC has both structural and functional connectivity with the PCC as part of the DMN [124], reciprocal interaction between the ACC and anterior insula serves as a major connection with the salience and reward network [125]. Interestingly, the negative correlation between memory performance (working memory) and impulsivity observed in our study was also previously reported by other studies on individuals with substance use disorders [126,127]. Lastly, as expected, non-planning and
