Relative sigma power

Female sex is associated with relative sigma power in humans.

“Female INS reported highest rates of insomnia severity as well as lower sigma power than males in the INS group.”

HumansInsomnia disorder; NREM sleepOne nightFemale versus malesn = 119

Beyond Aging, Sex and Insomnia Disorder Shape NREM Brain Oscillations

bioRxiv (Cold Spring Harbor Laboratory)·19 Mar 2026Preprint