Global efficiency, the harmonic mean of the minimum path length between each pair of nodes, is an alternative measure of connectivity of the network. This measure overcomes some of the limitations of the original measure of network connectivity, characteristic path length, which is susceptible to disconnected nodes. We examined global efficiency (E global) values obtained for the functional brain networks constructed by thresholding (threshold values ranged from 0.01 to 0.99 with an increment of 0.01), the wavelet correlation matrix at each of the three scales. The mean E global for both groups, when controlled for the degree of the network, was low (0.7<E global<1) and showed similar trends at all three scales. In the frequency interval 0.01–0.05 Hz (scale 3), mean E global values for the two groups, obtained by thresholding the correlation matrices such that the network has on average K′ ( = 48) edges per node, which is equivalent to a network cost of 0.54 were compared. No significant differences in the mean E global values were observed between the two groups.
