I usually sleep no more than five or six hours a night. Between my jobs as a neurosurgeon, CNN medical correspondent, TIME contributor and new daddy, that's all I can afford. And frankly, it always seemed like enough.
Sure, I might get a little tired by mid-afternoon, and I know that experts recommend eight hours. But you can get a lot done in those extra two or three hours, especially when the rest of the world (not to mention the baby) is asleep. So when my CNN producers and I decided to put together a series of stories on sleep
, it seemed a good opportunity to figure out just how much I really need.
For six months, we crisscrossed the country, interviewing sleep experts, getting tested in sleep labs and even flying a 747 simulator after being awake for 30 hours. I got my first clue that I might be more sleep deprived than I thought in a lab run by Robert Stickgold, a cognitive neuroscientist at Harvard Medical School.
I was wired with electrodes all over my head (including my eyelids) and two cameras recorded my every move. Everybody figured that with all the distractions, I would have trouble sleeping. As it happens, I was out almost immediately -- faster, according to the researchers, than anybody they had ever studied. It has given me new insight into my wife's complaint that I'm often asleep before my head hits the pillow.
I was sleep deprived. So what? Still confident that there was nothing wrong with my ability to function at full capacity, I flew to San Francisco, where NASA's Ames Research Center keeps a full-size virtual-motion simulator of a Boeing 747 jumbo jet. It's the next best thing to really flying. After a few hours of training and several takeoffs and landings, I had mastered the 747 -- or so I thought.
My assignment was to stay awake to the point of sleep deprivation and then try to fly again. After being awake for 30 hours, I felt more exhausted than I could ever remember. Then I was back in the cockpit. Remarkably, all those simple landing sequences were suddenly much harder to remember. Just keeping the nose of the plane level was a real challenge. Had I been flying a real 747, my passengers would have had a very bumpy ride.
My experience, I learned, is hardly unique.
If you have been up for more than 20 hours, your reflexes are roughly comparable to those of someone with a blood-alcohol level of 0.08, which in many states is enough to be considered legally drunk. You should not drive, and you most certainly should not fly a plane, in that condition. Moreover, the effects add up. Sleeping only six hours a night for a week makes you as tired on the seventh night as if you had had no sleep at all.
Having seen firsthand what sleep deprivation can do, I'm now making a conscious effort to get more shut-eye. I still don't know why we sleep in the first place, but I have a much better feel for what happens if we don't.