Leo Sher, M.D.

Our research article, “Evidence from the waking electroencephalogram that short sleepers live under higher homeostatic sleep pressure than long sleepers” was published 20 years ago in the March 2001 issue of Neuroscience (1).

We used the waking electroencephalogram to study the homeostatic sleep regulatory process in human short sleepers and long sleepers. Two- to four-week sleep logs and wrist motor activity recordings were used to identify individuals who met the study criteria. After sleeping according to their habitual schedule, nine short sleepers (sleep duration < 6 hours; mean age 25.9; range 22–31; five women, four men) and eight long sleepers (sleep duration > 9 hours; mean age 24.1; range 20–30; four women, four men) were recorded half-hourly during approximately 40 hours of wakefulness in a constant routine protocol.

Within the frequency range of 0.25-20.0 Hz, spectral power density in the 5.25-9.0 and 17.25-18.0 Hz ranges was higher in short sleepers than in long sleepers. In both groups, increasing time awake was associated with an increase of theta/low-frequency alpha activity (5.25-9.0 Hz), whose kinetics followed a saturating exponential function. The time constant did not differ between groups and was similar to the previously obtained time constant of the wake-dependent increase of slow-wave activity (0.75-4.5 Hz) in the sleep electroencephalogram. In addition, the time constant of the decrease of slow-wave activity during extended recovery sleep following the constant routine did not differ between groups. However, short sleepers showed an abiding enhancement of theta/low-frequency alpha activity during wakefulness after recovery sleep that was independent of the homeostatic process.

While the kinetics of the homeostatic process does not differ between the two groups, short sleepers live under and tolerate higher homeostatic sleep pressure than long sleepers. Our study also shows that important aspects of sleep regulation can be studied during wakefulness.

Reference

1. Aeschbach D, Postolache TT, Sher L, Matthews JR, Jackson MA, Wehr TA. Evidence from the waking electroencephalogram that short sleepers live under higher homeostatic sleep pressure than long sleepers. Neuroscience. 2001;102(3):493-502. doi: 10.1016/s0306-4522(00)00518-2.