The 3-D brain connectivity map of all significant FC connections (p < 0.05), which contributed to group classification, is shown in Figure 5. Results showed that 29 FC connections, involving all 12 seeds and all five frequency bands, were significant at the p < 0.05 threshold. The distribution of the connections across the frequency bands were: The nodes of these 29 connections were predominantly connecting to right hemisphere (33 right vs. 25 left). Four of the 29 connections represented more than once across different frequencies (Figure 5, panel f): (i) hyperconnectivity across R.PCC–R.PFC in delta, beta, and gamma bands, (ii) hyperconnectivity across R.PFC–L.LTC in alpha and beta bands, (iii) hyperconnectivity across R.LTC–R.PHG in delta and alpha bands, and (iv) hyperconnectivity across L.ACC–R.PHG in beta band and hypoconnectivity of the same in gamma band (Figure 5, panel-f). While the AUD group showed a predominant pattern of hyperconnectivity, except four prefrontal connections that showed hypoconnectivity (L.PFC–R.PFC, R.PFC–R.LTC, R.PFC–R.IPL in delta band and L.ACC–R.PHG in beta band) (Figure 5). Among these 29 significant connections, bilateral hippocampal (PHG) connections (13 out of 29) with other DMN nodes was a predominant feature with hyperconnectivity in all but one of its connections (L.ACC–R.PHG) in beta band.
