My son-in-law is an insomniac like me. A self-described nerd, he also knows more than just anybody else on the planet. I mean, who among your acquaintances reads science text books for fun? So when Ryan told me that sleeping through the night was a relatively recent innovation (or in my case, merely a ideal to be wished for), I was intrigued. Centuries ago, he said, people routinely slept in two shifts, and were awake for a couple of hours in the middle of the night.
If you suffer sleep insomnia and find yourself bright-eyed in the wee hours, you can take some solace in the fact that it's not just you – or you and all your same-age friends. Bifucated sleeping has been going on for eons. There are references to "first sleep" and "second sleep" back in the Middle Ages when you couldn't even snap open your laptop and stream The Good Wife episode you missed last week. In fact, you couldn't even snap on a light. A recent opinion piece in the New York Times by David K. Randall, author of Dreamland: Adventures in the Strange Science of Sleep, examines sleep research and the split-sleep schedule.
I found this article absolutely fascinating and recommend that you hop on over and read the entire thing. But life being what it is, you may not have time so I'll give you the highlights here.
The Times article cites a study done at the National Institute of Mental Health where subjects experienced no artificial light (say, the screen glow from a 2 a.m. Law & Order rerun!). At first, the subjects slept through the night, but then they established a pattern of waking up for a couple of hours after midnight. Other research suggests that any deep sleep, whether it comes in the conventional eight-hour package or not, "primes" our brain to function better, among other things, giving us an opportunity to clean off our desks, deciding which information to file for future reference and which to toss in the trash.
Randall's conclusion is that we should stop straining toward the unrealistic ideal of an unbroken eight hours of sleep. He's an advocate of power naps, and points out that nearly a third of all working adults in the U.S. get six hours or fewer of sleep a night, according to a CDC study.
I'm feeling much better about my restless nights. I figure I get seven hours sleep on average, and it seems to be enough. I may think about sleep insomnia on a day when I'm dragging. But I'm going to try to look on the bright side: I'm not an insomniac, I'm just carrying on the great tradition of split sleep.