Sex differences in human brain dynamics assessed with edge functional connectivity.

Numerous sex/gender differences in the human brain have been documented, including anatomical differences and differences in structural and functional connectivity, but many of these differences are critically sensitive to methodology and many are eliminated if total brain volume is controlled for. In this study, evidence is provided for a sex/gender difference in brain network dynamics during resting state inferred from edge functional connectivity. The analyses use data from the Human Connectome Project allowing a relatively large sample size (N = 1024). Analyses of peak heights and trough durations in a whole brain measure of brain network dynamics based on edge functional connectivity suggest that males show less frequent alterations than females. This difference exists across multiple definitions of peak heights and trough durations, and when covaried with age and brain volume. Similar analyses using nodes within the default mode network found longer male trough durations and higher female peak heights. These results provide preliminary evidence of possible sex/gender related differences in brain dynamics when participants are in a resting state, and suggest that further studies of dynamics under other conditions may be illuminating.