RIGHT WAY TO SLEEP NATIONAL GEOGRAPHY After waking up in the middle of the night every day for a week, today you might be diagnosed with insomnia and prescribed sleep medication. But just a few generations ago, this may hardly have been reason for concern, let alone medical intervention.
Waking in the middle of the night was common, if not the norm, in western preindustrial cultures, according to Roger Ekirch, a professor of history at Virginia Tech whose research into segmented sleep became the basis for his book, *At Day's Close: Night in Times Past*. With schedules dictated by the sun rather than clocks and electric lights, people likely retired to bed earlier and, instead of a quick, continuous eight hours, may have enjoyed a longer rest period, that included two shorter sleeps interrupted by a bout of wakefulness. Not everyone agrees. Some research shows hunter-gatherer communities might have been sleeping in one go, much as we do now. This data could also indicate that multiple sleep sessions was never the norm in societies around the world, even before the Industrial Revolution. Today, with electricity to lengthen our waking hours and alarms to cut short our repose, most people try to sleep in one continuous bout. But some experts debate whether intermittent sleeping is natural—and the potential benefits of different sleep patterns in modern life. What is polyphasic sleep? Segmented sleep consists of two (biphasic) or more (polyphasic) periods of sleep punctuated by periods of wake—both of which can range <https://pubmed.ncbi.nlm.nih.gov/6504414/> from minutes to hours depending on the species. Studies estimate that over 86 percent of mammals <https://link.springer.com/chapter/10.1007/978-1-4757-2210-9_1#Bib1>, including dogs, rodents, hedgehogs, and even certain whales, sleep in several bouts. Until recently, humans were believed to be among the minority of species—including most primates—that are strictly monophasic sleepers. That hypothesis was wrong, says Russell Foster, a professor of circadian neuroscience at the University of Oxford. Historical records contain evidence of biphasic sleeping habits in humans dating back hundreds of years. According to Ekirch, sleep in preindustrial western civilizations happened in two shifts. People would sleep for several hours, and reawaken sometime after midnight for an hour or so of meditation, sex, and socialization before returning to bed for the second sleep. A mother humpback whale supports its calf near the surface while they sleep. Most humpback whales are believed to sleep in several phases either during the day or night. But some experts believe that this behavior may still be in our nature. In his 1992 pioneering work on the subject <https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1365-2869.1992.tb00019.x>, psychiatrist and scientist emeritus of the National Institute of Mental Health Thomas Wehr observed that, after several weeks of being confined to a dark room for 14 hours per day, nearly all participants had shifted into a segmented sleep cycle. “On average, for the whole group, it was bimodal,” Wehr says. He found that people tended to fall asleep first in the evening and again towards early morning. “The average pattern was very similar to sleep in some diurnal, day-active animals like panthers.” Biological and psychological reasons for polyphasic sleep? >From a physiological perspective, bifurcated sleep makes sense, says Daniel Buysse, a professor of psychiatry, medicine, and clinical and translational science at the University of Pittsburgh. Dual sleep processes (homeostatic and circadian), are “smushed together” with our condensed sleep schedule, says Buysse. Given more time, he adds, the processes might separate in time, allowing us to naturally wake between cycles. In fact, these periods of wakefulness between sleep could even serve a survival function. In his experiment, Wehr noticed that participants would wake up at slightly different times each night and that, on average, there was no time when every single person was asleep. From an evolutionary perspective, this might have served a “sentinel function” by making sure that there was always someone awake to keep watch for the group. Some have pushed polyphasic sleep as a way to “biohack” the body and extend waking hours. However, experts widely discourage this. Tricking the body into surviving on shorter spurts of sleep is not the same as waking naturally from well-rested slumber, says Elizabeth Klerman, who co-authored a 2021 paper <https://www.sleephealthjournal.org/article/S2352-7218(21)00030-9/fulltext> with Foster analyzing the impacts of artificial polyphasic sleep. She asks, “Would you stop a washing machine before the cycle’s over?” K RAJARAM IRS 1825 -- You received this message because you are subscribed to the Google Groups "Thatha_Patty" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/thatha_patty/CAL5XZooQ%3DxVTAUO0t8P_uzMyBKKN2DdL_ih%2BknbmaZoAgASZdA%40mail.gmail.com.
