experiencelifemag.com Print › | Back › A Brief History of Sleep By Karen Olson June 2009 Before the industrial revolution, people typically slept in two shifts, explains historian A. Roger Ekirch in At Day’s Close: Night in Times Past (W.W. Norton, 2006). Within about an hour after sunset, people would retire for a four-hour “first sleep.” They’d then get up for a few hours to do some chores, be with family and friends, or take time for quiet contemplation. At about 2 a.m. they’d go back to bed for their “second sleep,” lasting another four hours or so. Some contemporary African tribes, including the Tiv of central Nigeria, have a similar pattern, even referring to first sleep and second sleep. Today, segmented sleep is no longer considered natural, despite the fact that many people, especially in winter when nights are longer, have this pattern. People who wake up during the night often think they have insomnia and grow frustrated. Sleep researchers Mary Carskadon, PhD, of Brown University and Todd Arnedt, PhD, of the University of Michigan have suggested that people who wake up in the night may feel better knowing that segmented sleep is a natural pattern. Thomas A. Wehr, MD, scientist emeritus at the National Institute of Mental Health (NIMH), has suggested that our current sleep pattern — falling asleep quickly and sleeping for an uninterrupted seven to eight hours — is the unnatural result of exposure to artificial light and chronic sleep deprivation. When Wehr was in charge of biological rhythm research at NIMH, he found that, after a few weeks of being deprived of artificial light, people eventually settled into a pattern of broken sleep that included a period of “non-anxious wakefulness.” This peaceful time, which Wehr likened to an altered state of consciousness similar to meditation, coincides with the period the brain reaches its highest levels of prolactin — a feel-good pituitary hormone that also reaches high levels after exercise, meals and sex. If you wake up in the middle of the night, enjoy it! If you feel rested and refreshed after sleeping seven to eight hours in a row — or five or 10, depending on your body’s requirements — that’s fabulous. When you know what feels best to you, it’s easier to prioritize making healthy sleep an important part of your life.

A Brief History of Sleep

Before the industrial revolution, people typically slept in two shifts, explains historian A. Roger Ekirch in At Day’s Close: Night in Times Past (W.W. Norton, 2006). Within about an hour after sunset, people would retire for a four-hour “first sleep.” They’d then get up for a few hours to do some chores, be with family and friends, or take time for quiet contemplation. At about 2 a.m. they’d go back to bed for their “second sleep,” lasting another four hours or so. Some contemporary African tribes, including the Tiv of central Nigeria, have a similar pattern, even referring to first sleep and second sleep.

Today, segmented sleep is no longer considered natural, despite the fact that many people, especially in winter when nights are longer, have this pattern. People who wake up during the night often think they have insomnia and grow frustrated. Sleep researchers Mary Carskadon, PhD, of Brown University and Todd Arnedt, PhD, of the University of Michigan have suggested that people who wake up in the night may feel better knowing that segmented sleep is a natural pattern.

Thomas A. Wehr, MD, scientist emeritus at the National Institute of Mental Health (NIMH), has suggested that our current sleep pattern — falling asleep quickly and sleeping for an uninterrupted seven to eight hours — is the unnatural result of exposure to artificial light and chronic sleep deprivation.

When Wehr was in charge of biological rhythm research at NIMH, he found that, after a few weeks of being deprived of artificial light, people eventually settled into a pattern of broken sleep that included a period of “non-anxious wakefulness.” This peaceful time, which Wehr likened to an altered state of consciousness similar to meditation, coincides with the period the brain reaches its highest levels of prolactin — a feel-good pituitary hormone that also reaches high levels after exercise, meals and sex.

If you wake up in the middle of the night, enjoy it! If you feel rested and refreshed after sleeping seven to eight hours in a row — or five or 10, depending on your body’s requirements — that’s fabulous. When you know what feels best to you, it’s easier to prioritize making healthy sleep an important part of your life.

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