Sleep Deprived

By Sanjay Gupta

I usually sleep no more than five or six hours a night. Between my jobs as a neurosurgeon, CNN 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 midafternoon, and I know that the 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 one-hour special 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.

All right, 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 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. A chronically sleep-deprived person will often go through repeated episodes of microsleep, sometimes accompanied by microdreams (which are usually interpreted as hallucinations). 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 be flying 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.

Sanjay Gupta's SLEEP special will air on CNN Sunday, March 26, at 10 p.m. ET