Fig. 4

Connectivity matrices of AEC-c. Connectivity matrices averaged across all epochs and subjects. Each row represents a different frequency band (delta, theta, alpha, beta, and gamma), and each column shows the results for the AEC-c, for the test and validation cohorts in the AD and SCD groups. All bands and groups show the matrices with the same scale. The ROIs are obtained from the AAL atlas. The matrices are ordered from the left to the right hemisphere in the following way: rows/columns 1–15 represent left frontal regions, 16–21 left parietal regions, 22–27 left occipital regions, 28–39 left temporal regions, 40–54 right frontal regions, 55–60 right parietal regions, 61–66 right occipital regions, 67–78 right temporal regions, and 79–90 subcortical regions (see also Table S1)