Greetings from beautiful San Francisco, which gracefully quivers above several famous and finicky fault lines, and whose intrepid citizens, unfazed by the constant promise of tectonic apocalypse rumbling in the earth below, snuggle in their beds each evening and manage to sleep soundly through the night.
Me? My room's a little stuffy. I didn't sleep a wink. But enough whining. Time to get busy. Today my quest for a good night's sleep begins in earnest, with a visit to the world-famous Stanford University Sleep Disorders Clinic, for a state-of-the-art, overnight sleep study.
A Study in Sleep
What's involved in a clinical sleep study? Nocturnal monitoring of my heart, my brain and my breathing, just for starters. They're also throwing in an "electron-oculogram" to measure my eye movements and a little "oxygen saturation by ear oximetry" action to gauge the oxygen content of my blood. For good measure they'll take a good look-see at my "esophageal pressure," which is done, it seems, by having me sleep with a plastic tube shoved down my gullet. (And isn't that an endearingly optimistic notion — me, the guy who makes the Princess and the Pea look like Rip Van Winkle — sleeping with some PVC hardware crammed in my throat?)
But I'm not complaining. With any luck, the Stanford crew will find the physiological roots of my sleep problems. They'll certainly be searching for signs of clinically recognized sleep disorders — I'll be discussing all that with them tomorrow — but they'll also be scrutinizing the rhythms of my sleep, to make sure I'm not suffering from a glitch in my basic sleep timing.
I've Got Rhythm
Didn't know your sleep had a sense of timing? You betcha. It all begins when you pull up the covers and turn off the lights, prompting your system to pave the way for sleep. In response, your muscles relax and your brain waves slow to a calming pace. As you grow drowsy, your mind abandons the focused, abstract thinking that gets you through the day, and begins to think more associatively, using pictures. (You know those visions you see as you drift off to sleep? They aren't dreams — you're still awake. Instead, they're a kind of thought-image known as a "hypnagogic hallucination.")
On a good night, this opening period of "restful wakefulness" will last no longer than five minutes. Then your brain waves slow even further and you drift slowly down through the successively deeper levels of slumber: The half-sleep of Sleep Stage 1 lasts two to five minutes; you spend 10 minutes or so in the real-but-shallow slumber of Sleep Stage 2; and finally you fall into the oblivion of Sleep Stages Three and Four — otherwise known as Delta sleep, the deepest, soundest sleep of all.
A Sleep on the Wild Side
The heavy slumber of the Delta stages lasts 30 quiet minutes or more. Then, about an hour and a half after you fall asleep, things grow suddenly antic: your pulse rate soars, your breathing becomes wildly erratic, and your eyes dart vigorously from side to side. The effect is identical to intense emotional agitation. Welcome to the fifth and final stage of sleep, the famous REM phase, named for its characteristic Rapid Eye Movements and proven to be the sleep stage during which most of our dreaming occurs.
REM phase, which lasts from 11 to 25 minutes, marks the end of a full sleep cycle. If you're a healthy sleeper, you'll move smoothly through one sleep cycle after another, until you awaken rested and refreshed in the morning. But if your cycles are off, even a full night's sleep will leave you feeling wasted. And that sounds familiar to me.
I'm betting my cycles are haywire. I'm getting cheated of those luscious delta wave Zs, I swear. But that's what we're paying the Stanford pros to tell us. You'll spot me easily: I'll be the guy choking on the plastic tube all night.