"The other interesting factor I like to use to illustrate the effect of sleep deprivation is that some very good studies have shown that if you've been awake for 18H hours -- which for most of us is extending our day by only a couple of hours -- your driving performance is the same as if your blood alcohol content was .05," Drummond says. "And if you've been awake 21 hours, which is not even a full all-nighter, your driving performance is the same as it would be if you had a blood alcohol of .08."
The scientist adds that the subjects of those studies were instructed to sleep eight hours before the day of their testing. Although some individuals require more sleep than that and some less, the majority of people are thought to need between seven and nine hours per night. The fact that substantial differences in sleep needs do exist, combined with the cultural pressures to sleep less, can make it hard for many people to know just how much sleep they should be getting. Renata Shafor, a local specialist in sleep medicine, says people often ask her to tell them how much sleep they need. She suggests, "Look back at your family members, especially the one you resemble the most." Sleep needs have a strong genetic component, she believes. "Or look at how much sleep your body requires when you're on vacation," she counsels.
Drummond points out additional clues to sleep deprivation. He says most people take about 20 minutes to wake up, but after that, "You should get up feeling refreshed. And then you should not feel sleepy during the day. That's the bottom line. If you are falling asleep or wanting to fall asleep in the middle of the day, it means one of two things: either you're not getting enough sleep or your blood sugar is way too low and you're not eating enough. It's one or the other. Typically, it's going to be the lack of sleep. If at three or four in the afternoon, you can sit for an hour in a dark room during a boring talk and stay awake, you're probably sleeping enough. But if your head starts to nod and you want to fall asleep, you're probably not getting enough sleep. You should not feel the need to sleep during the day if you're getting enough sleep at night." (He adds that in cultures with siestas, people typically sleep less at night.)
For someone who's sleep-deprived because he's staying up for Letterman or blogging into the wee hours, the alternative to feeling exhausted may be as simple as scheduling more time in bed and making sleep a priority. But for a substantial number of Americans, opportunity alone isn't sufficient; once they're in bed, they still can't sleep as well as they would like. According to the National Sleep Foundation's 2002 "Sleep in America" poll, 74 percent of those surveyed reported having at least one of the following problems a few nights a week or more: difficulty falling asleep; waking a lot during the night; waking up too early and not being able to get back to sleep; waking up feeling unrefreshed; snoring; having unpleasant tingling feelings in the legs; and having pauses in nocturnal breathing.
Those are the sorts of torments that come to light in Renata Shafor's office, a modest two-story stucco building on Third Avenue, just north of Elm, downtown. For almost 20 years, Shafor has been a specialist in sleep medicine. It's a field that didn't exist when she attended medical school in the early 1960s in Chisinau, Moldova (then part of the Soviet Union). "I wanted to be a neurologist, but there really was no possibility for me at that time," she says. Instead she worked as a family practitioner in Odessa, where "I made a lot of house calls." In 1979, she and her family emigrated, settling in Saint Louis, and Shafor eventually passed the examinations necessary to earn her American medical license. She was delighted to find a residency in neurology at the University of Missouri, Columbia, "and when questions came up about a fellowship, the dean said to me, 'There is a fellowship in an absolutely new field. I'm sure you're going to like it. And it's in a wonderful place: San Diego.' " Although Shafor says she was dubious at first, and her husband kept asking, "Are you sure this isn't a gimmick?" the fellowship proved to be "a priceless experience."
A petite woman with a gentle but confident demeanor, Shafor still speaks with a heavy Russian accent. She says when she arrived in San Diego in 1984, she was the first fellow in sleep disorders in the United States, and she wound up getting exposed to a little bit of everything. Although she spent the majority of her time in Scripps Clinic's then-new sleep-disorders clinic, she also was introduced to the Naval Hospital and VA research programs, and she went up to Stanford for a month and immersed herself in the work there. Today a photo from her Northern California sojourn hangs on the wall in her office. A girlish, glowing Shafor stands between two men, one in his mid-60s and the other his senior. The younger man was Dement, Shafor says, while the older one was Dement's mentor, Nathaniel Kleitman, "the guy who opened up the sleep field."
Another native of Chisinau (born back when Moldova was part of Romania), Kleitman today is recognized as the first scholar in the world to concentrate on sleep. He joined the faculty of the University of Chicago in 1925 and by the late 1930s had devised an experiment that fired the nation's imagination. Kleitman and a colleague spent a month living deep within Kentucky's Mammoth Cave, far removed from the regulating influence of sunlight and human society. Their aim was to study whether they could adjust to a schedule of 28-hour days. Although the results of their stay were inconclusive (one man adjusted, while the other did not), subsequent investigation revealed that human beings do appear to have an innate biological clock that runs on a cycle just under 25 hours long.