I have always been an intermittent sleeper, a condition that goes back as far as I can remember, certainly back to late childhood. Regardless of when I turn off the light at night or when I have to be up in the morning, I awaken three or four times at night. Usually, I just glance at the bedside clock, roll over, and go back to sleep. Sometimes I will get out of bed, drink a glass of water, walk through the apartment—although no sound or warning had actually awakened me—pause to look at the Moon, then get back into bed. Sometimes, less often, I will sit up and think for a bit before drifting off to sleep.1
For years I have noticed that the sleep-wake cycle seems to be in roughly 90-minute intervals. If I turn out the light at 11 p.m., I awaken at 12:30 a.m., then about 2:00 … 3:30 … 5:00. Sometimes I’ll miss a waking phase. Sometimes I’ll sleep through for two hours and then awaken. But the overall pattern is discernible.2
I did not realize the significance of the 90-minute cycle until last year, when I heard Allison Harvey, a U.C. Berkeley professor of psychology and sleep expert, speak at our NAMI East Bay chapter on the benefits of good sleep.3 She explained that human beings cycle through various sleep stages, going down to deeper and deeper levels, and then gradually rising to a short period of dreaming sleep—characterized by rapid eye movement, or REM—every 90 minutes or so. Most people continue sleeping and go back to deeper levels after the REM sleep. The REM periods get longer and longer during the night. Some people tend to awaken in the sixth hour after the third REM period and then fall back asleep for another two hours. I seem to be the exception who awakens more frequently.
Two notions about these short periods of wakefulness have become commonplace with me over the years.
First, if I’m wrestling with a problem—a troubling plot point in a book, say, or a logical or factual error in a recent passage that my subconscious suspects but I can’t quite identify, or a word choice that isn’t quite right—then an idea, answer, or correction will generally pop out when I awaken in the middle of the night. That’s why I keep a notepad and a pencil on the nightstand. If I try to remember the thought by simply holding it in my mind, it will surely be gone by morning. But just by jotting down a word or two—usually in darkness, by touch, using a blind scrawl that even I have trouble deciphering in daylight—I can bring back the sequence of thoughts and move ahead with them.
Second, if I happen to think about my life situation when I awaken in the middle of the night—about some course of action or direction I’ve chosen, some personal exchange I’ve recently had, or even just a summing up of where I stand and who I am—that evaluation will be uniformly negative. My thoughts at 3 a.m. are cold and harsh, judgmental, difficult … sometimes crushing. I used to think that this was the “real me” or “reality.” That what we find when we awaken at 3 a.m. is our actual situation unadorned by the pleasant lies we tell ourselves to keep moving forward during the day. The mask and its smile are stripped away, and 3 a.m. is the hour of the naked soul. These are not thoughts that I tend to jot down on the notepad, but if I remember them in the morning—because they tend to be harsh jolts—I then wonder what had slipped, and where reality actually lies.
Now I think I know.
While sleep itself is a great restorer of bodily function through muscle relaxation, endocrine rebalancing, and natural healing processes, what it does for the mind is more controversial. REM sleep involves a kind of inadvertent hallucination: the mind tells itself stories, sometimes very real seeming, sometimes knowingly fanciful, and usually related only tangentially to anything that might have happened during the preceding day. During REM sleep the body experiences a kind of muscular paralysis, so that the imagined visions, sensations, and actions pursued in dreams don’t result in thrashing limbs and personal injury.4
It’s understood that people deprived of sleep itself—whether kept from all sleep for a couple of days, or experiencing insufficient sleep during their daily cycle—become fatigued, error-prone, clumsy, irritable, and even physically sick. Complete sleep deprivation can cause hallucinations, mania, and finally death. But what part in particular the dreams of REM sleep play in healing the brain and mind—as compared with the other, deeper sleep stages—is unknown. Interestingly, studies where sleepers were awakened whenever the familiar eye movements and EEG patterns of dreaming began have proven that people can be deprived of REM sleep for quite long periods without harmful effect. It’s lack of sleep itself that is damaging.
But a night’s sleep is not one singular experience. As noted above, it comes in a regular and repeated pattern: successively deeper sleep stages, followed by shallower stages, then a period REM sleep, then off to the deep end again. This 90-minute cycle repeats four or five times a night. So we can conclude that whatever sleep does, it achieves in small doses that include both deep, dreamless sleep and light, dreaming sleep.
Scientific theories about sleep and its effects on the brain and mind abound: that sleep lets the nerve cells rebuild their stocks of the energy molecule, adenosine triphosphate (ATP); that sleep supports the selective formation of long-term memories from among the past day’s short-term memory events; that during sleep, interleukin-1 levels rise and immune system functions are promoted; that at a minimum, sleep allows the mind to pause, let go of current concerns and anxieties, work off its emotional buildup, and prepare for a new day. That is, in general, during sleep the brain rebuilds, digests, repairs, and prepares.
What does all this suggest for someone who has suddenly come awake at 3 a.m.?
For the solution to intellectual problems like plot fixes, logical errors, and word choices, the brain is riffling through its index cards of the past day’s events and tossing off random thoughts. If I’ve prompted myself with a thought before bedtime about solving a certain problem, then something related is likely to get bundled into all that activity. If I’m awake at the right time, the solution will pop into my mind, and I can capture it if I write it down. If I simply try to remember it for tomorrow, it will get tossed with the other short-term trash.
For the solution to emotional problems like who I am and where I’m going, the brain is randomly processing and discarding the past day’s emotions. Most of these will be hurtful, doubtful, and damaging thoughts, because those are the things that nag and worry us. Happy thoughts and hopeful expectations we tend to accept calmly as part of our emotional birthright. It would be an error, then, to think of the nighttime shuffling of our emotional baggage as a more truthful form of reality than the mix of hope, expectation, and conscious emotional balance that reflects our healthy daytime mind.
In either case, the wavelike nature of the sleep cycle—with each 90-minute segment undertaking to wash only some part, but not all, of the past day’s dirty dishes—suggests that experiencing just one time point, bang! awake at 3 a.m., will sample only a fraction of the entire process. The problem solution that the brain tosses out is not necessarily the final word on the relevant subject. It’s only a kernel, a fractal of thought and understanding, which then needs to be reexamined and expanded in the light of day with a fully awake mind and a refreshed perspective. The personal evaluation that the brain tosses out is just a fragment of feeling from a personality that’s undergoing repair, a personality in transition between the stages of emotional dissolution and reassembly. That evaluation also needs to be reexamined after the mind has re-integrated itself.
Mid-sleep awakenings can yield a provocatively fruitful source of ideas and inspiration—but they will still need development and evaluation with a clear head. The same awakenings can yield a deceptively convincing judgment on personal worth and direction—which is better left to an unconfused mind.
1. The only time this pattern breaks is when I am sick. Then I might sleep through the night without waking. But when I’m healthy, I tend to sleep in small batches.
2. This pattern might relate to something else I’ve noted about myself: I have a very accurate internal clock. If I need to be awake at a certain time, I will set the alarm out of habit, but I tend to come bolt-awake one minute before the alarm goes off. During the day, I generally know within a few minutes’ accuracy what time it is without looking at my watch. And I am very good at estimating the time requirements for various planned activities and assignments, for travel and connections, and for contingencies. I have a pretty good clock in my head. This seems to accompany my “bump of direction”: I can usually tell which way points north, where the sun is at any give time under cloud cover, and where I’ve been so I can retrace my route. I blame the Earth’s magnetic field for all this.
3. NAMI is the National Alliance on Mental Illness, and I volunteer at our local chapter to write up the speaker meetings for their bimonthly newsletter. See Sleep Better … Feel Better from March 23, 2011, in my NAMI Speaker Notes. The second page of the Harvey article includes a chart of the REM cycles described above.
4. Given that sleep is a particularly mammalian phenomenon—originally experienced during the day, when our mouselike, nocturnal ancestors had to lie low while the predator dinosaurs were awake and active—it makes sense that natural survival mechanisms would keep our bodies subdued despite whatever might be passing through our minds.