The RF correctly classified 24 out of 30 subjects in each group with an accuracy rate of 80%. The model identified 29 FC connections (across multiple DMN nodes representing all frequency bands), three neuropsychological variables from the VST (total number of correctly performed trials in forward and backward sequences and average time of correct trials in forward sequence) and all 4 impulsivity scores (motor, non-planning, attentional, and total) as significantly contributing to classifying individuals into either AUD or CTL group (Table 3 and Figure 2 and Figure 3) based on specific RF parameters (Figure 4). The significant FC connections revealed that AUD group showed a predominant pattern of hyperconnectivity (i.e., increased FC) in all frequency bands (25 out of 29 connections), and only four connections with hypoconnectivity (three in delta and one in beta band) (Figure 5). Interestingly, 13 of the 29 connections (45%) were bilateral hippocampal (PHG) connections with other DMN nodes (bilateral PCC, bilateral ACC, R.IPL, bilateral PFC, bilateral LTC), in which AUD showed hyperconnectivity in 12 connections across all frequency bands, and hypoconnectivity (i.e., decreased FC) across
