Fig. 2: Effect of aging on FC
(a) Median change in power scalp plots in three frequency bands: alpha (top row), slow gamma (middle row), and fast gamma (bottom row) across middle-aged (N=91) and elderly (N=127) subjects. (b) Median PPC FC scalp map for the two age groups, averaged across the maps with the seed electrodes in the left and right group (after flipping around the vertical axis), along with 25% normalized FC contour in red. (c) PPC with inter-electrode distance plotted over linearly spaced bins in cosine of angular separation, averaged for each of the seed electrodes within left and right groups and then taking the median over subjects. Bins that are significantly different across middle-aged and elderly groups (p<0.01; KW test) are marked with an asterisk (*). (d) FC values averaged across bins with \(cos(\Delta\theta)\) in the range [-0.5 ‒ 0.5] for the two age-groups, separately for the right and left seed electrode groups. The asterisk * means p<0.01, uncorrected for multiple comparisons, obtained using KW test across the age groups within each bin.