Sex Difference in EEG Functional Connectivity during Sleep Stages and Resting Wake State Based on Weighted Phase Lag Index

Men and women were reported to be different in brain structure and sleep patterns. Here we analyzed the region, sleep stage and frequency band-specific EEG synchronization intensity of whole night sleep recording of 14 male and 14 age-matched female subjects by calculating weighted phase lag indexes. Moreover, resting wakeful stage EEG was also analyzed and compared. The synchronization intensities showed significant gender differences in all stages and bands: higher in women in non-rapid eye movement (NREM) sleep, and higher in men in α and β bands in wakeful stage and rapid eye movement (REM) sleep. However, Except for α band, the similar changing trends in characteristics of EEG synchronization during different stages were found in both male and female subjects. These results suggest that there may be some differences in the mechanisms of sleep regulation between men and women. Moreover, the synchronous intensity of different sleep stages in different frequency bands of male and female groups was not consistent with the influence of age, which may be related to the gender differences in aging patterns.