Discussion
We studied the change in stimulus-induced EEG FC, computed using PPC,
with aging and cognitive impairment in elderly (>49 years)
human subjects. With healthy aging, although power reduced in slow and
fast gamma bands but not alpha band (Murty et al. , 2020), FC
reduced in alpha and slow-gamma but not in fast-gamma band. These
results remained consistent even when power in the two age groups were
matched or accounted for using multiple linear regression. On the other
hand, cognitive decline due to MCI reduced power in both slow and fast
gamma but not alpha band (Murty et al., 2021), while FC reduced only in
the slow gamma band. The reduction in slow gamma FC was observed even
when power was matched for the two age groups. These results remained
consistent across the left, right, and back electrode groups and over
other FC measures, such as coherence and PLV.