A: In MCI patients, a significant correlation was found between WMLL and RS-fMRI DMN connectivity strength (i.e., average Z) over the reduced regions (i.e., reduced medial prefrontal cortex connectivity in MCI patients compared with controls) (r = 0.56; P = 0.02). Furthermore, there was also a significant correlation between WMLL and RS-fMRI fALFF average Z over the reduced regions (i.e., reduced temporal cortex activity in MCI patients compared with controls) (r = 0.63; P = 0.01). B: In AD patients, a marginal interregional correlation exists between the fALFF activity values (i.e., average Z values) over the reduced regions (i.e., decreased medial prefrontal cortex activity in AD patients compared with MCI patients) and increased regions (i.e., increased parietal cortex activity in AD patients compared with MCI patients) (r = 0.46; P = 0.11); and a significant correlation was found between amyloid load (rSUV) over the whole cerebral cortex and fALFF activity over the reduced regions (r = 0.64; P = 0.046) in AD patients.