According to Ekirch, the historical evidence bears that out. Wehr's study subjects normally awakened from REM sleep, which is the deep sleep stage during which dreams occur. One benefit of biphasic sleeping may be that it makes it easier to recall and access dreams. He also inferred that modern humans are chronically sleep-deprived, which may be why we usually take only 15 minutes to fall asleep, and why we try our best not to wake up in the night. Wehr concluded that biphasic sleeping is the most natural sleep pattern, and is actually beneficial, rather than a form of insomnia. In Wehr's well-known study, he subjected participants to 14 hours of darkness per night, and found that they gradually shifted to a routine of taking two hours to fall asleep, then sleeping in two four-hour phases separated by about an hour of wakefulness-a pattern that exactly matched Ekirch's historical findings. In the 1990s, a sleep scientist named Thomas Wehr discovered that everyone sleeps biphasically when subjected to natural patterns of light and dark. "But people with particularly strong circadian rhythms continue to ," said Ekirch. Now, "normal" sleep requires forgoing the periods of wakefulness that used to break up the night we simply don't have time for a midnight chat with the neighbor any longer. At the same time, it has cut nighttime short, and so to get enough sleep we now have to do it all in one go.
In places with electricity, though, artificial lighting has prolonged our experience of daylight, allowing us to be productive for longer.
Segmented or biphasic sleep patterns evolved to fill the long stretch of nighttime, and as observed by anthropologists, segmented sleep continues to be the norm for many people in undeveloped parts of the world, such as the Tiv group in Central Nigeria.
Except for those affluent enough to burn candles for hours, folks were left with little to do but go to bed early, and this gave a great deal of flexibility to their nightly sleep requirements. You can blame the shift in your sleeping habits on Thomas Edison's lightbulb and the Industrial Revolution.Įkirch explained that in the past, and especially during winter, darkness spanned up to 14 hours each night.
0 kommentar(er)
