Dreamland: Adventures in the Strange Science of Sleep
David K. Randall
W.W. Norton & Co.
Like most people with a chronic case of being human, I often have trouble with sleep. I am a particularly light sleeper blessed (?) with an excellent sense of hearing. I live out in the boonies so it’s often the wildlife that wakes me up at night, whether it’s mice scrabbling in the ceiling, birds heralding the dawn, or, occasionally, a stag bumping his antlers against my window while devouring my strawberries. If I have anything the least bit worrying going on I can pretty much count on a night of insomnia. Thanks to M.E. (chronic fatigue syndrome), I can also expect wakefulness if I exert myself too much during the day—I literally become too tired to sleep (a mysterious symptom common to neurological disorders).
Considering what a problem it is, I wonder why I’ve only read one book about it before now. That book, the excellent Sleep Thieves by Stanley Coren, was mostly about the consequences of not getting enough sleep: low grades, car accidents, plane crashes, medical errors, and other dire outcomes. The message was that we could probably all do with more sleep, a lot more. Traditional societies without so many clocks and electric lights tend to sleep about 8.5 hours and night and another 1.5 during an afternoon nap. Other sleep experiments confirm that the modern notion of only needing 5 or 6 or even 8 hours of sleep is delusional. Anyone getting less than 9 or 10 hours of sleep a night is simply not functioning at their full potential.
While Dreamland covers some of that territory as well (including harrowing tales of military disasters caused by sleep-deprivation), it is more about sleep disorders and the big question of why we (and every other animal) need to sleep. I found the chapter on dreaming most enlightening. Ever since Freud (and the subsequent debunking of Freud), studying dreams has been regarded as only slightly more legitimate than studying UFOs, so there hasn’t been a lot of research on dreams, but what there has been is starting to make some headway (no pun intended).
There are actually several things going on when we dream, sometimes in concert with other phases of sleep. I had heard before that we are more likely to remember unpleasant dreams but as it turns out, most of our dreams are negative. It seems to be our way of dealing with potential or actual threats, either by looking for solutions, trying to adjust to the new reality, or simply storing it in long-term memory so we can recognize the danger next time. [Coincidentally, sleep is also the time when the immune system sweeps the body for foreign invaders and we repair any damage done during the day. Both physical and psychological defenses are working the hardest when we sleep.] Dreams usually start out as a fairly literal rehearsal or restaging of the thing that’s worrying us. Since we rarely wake from these dreams we don’t remember them. As the night progresses our brain starts to make associations between the subject of the dream and things we already have in our long-term memory. As these connections develop and grow, our dreams get weirder, until we finally end up talking to a dead relative who turns into a parrot on a pirate ship bound for Mars.
This process of associating day-to-day events with our long-term memories is also what drives learning. If sleep is interrupted the night after learning something new, particularly in the first half of the night, we retain much less the next day. Also, taking a nap after learning improves memory retention. So the next time you see a student asleep over their books, leave them alone—they’re learning! Associations may also play a role in the phenomenon of waking up with a solution to a problem that we couldn’t solve during the previous day. With the (self-)conscious mind out of the way, the free-associating brain can sift through all sorts of possible combinations until it finds one that fits.
It seems that our brains are nearly as busy when we are asleep as when we are awake, the only difference is that our bodies are (or should be) paralyzed, and we are unconscious. Consciousness, as it turns out, is not one thing, but has several components located in different parts of the brain and goes through different stages during sleep. If those stages aren’t properly coordinated you can get problems like sleepwalking, sleepeating, sleepdriving, and even sleepmurder. It was a painful episode of sleepwalking that prompted the author to begin investigating sleep. It is entirely possible to get up, have a snack, drive across town, or bash someone over the head with a tire iron while asleep. There is no consciousness, but most other brain functions are working and the body is not paralyzed so it does what it dreams. Some sleepwalkers tie themselves to their beds for fear of jumping out of a window by accident. There isn’t much doctors can do about it other than prescribe muscle relaxants that help keep the body still.
The author didn’t really find a solution to his sleepwalking problem, and this is not intended as a self-help book. It does discuss how cognitive behavioural therapy, relaxation, and “sleep hygiene” (best practices for sleeping—I’ll let you Google it) are more effective than sleeping pills for dealing with chronic insomnia. But I think the main message of the book is that we need to take sleep more seriously. Modern people tend to see sleep and sleepiness as negotiable and manageable with enough caffeine. We also see it as something we should just be able to do, like eating and breathing. Neither attitude is based on reality. Sleep has profound effect on every area of our lives, from academic performance to marital happiness. If there is something not working in your life, sleep should perhaps be the first place to look. As mysterious as it is, we do know a lot about how to improve the quality of our sleep. We can and should inform ourselves about sleep and plan for it in the same way that we research and make plans to improve our fitness, education, career, or anything else important in our lives. We’re dreaming if we think we can get the most out of life without being conscientious about sleep.