Catnaps. While they come naturally to some, others find them utterly elusive. The ease with which some people fall asleep despite a noisy environment intrigued one New York Times reporter enough to ask how so many New Yorkers manage to doze on the subway, and more importantly, whether it's a total waste of time. When she contacted Carl W. Bazil, MD, PhD, director of the Epilepsy and Sleep Division at New York-Presbyterian Hospital/Columbia University Medical Center, he agreed to help her find out, later enlisting the aid of one very sleep-deprived neurology fellow.
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As Dr. Bazil told Neurology Today, the results were a surprise — even to him. Those of you who are relaxed enough, or tired enough, to be able to fall asleep in lectures, during meetings, or on your daily commute by subway, bus, or train, will be sure to appreciate his findings. (And the rest of us may become envious.)
HAD YOU OBSERVED SUBWAY SLEEPERS BEFORE?
I ride the same train used on this study every day, for 30-45 minutes each way. I donIt fall asleep; I usually read and, like a real New Yorker, tend to bury my eyes in a journal or book and not pay attention to whatts going on. I'm a little embarrassed that, as a sleep specialist, I never paid much attention to people sleeping, although I certainly saw it.
HOW WAS THIS EXPERIMENT CONCEIVED?
Christine Haughney, the reporter, called me and said she had become interested in people sleeping on the subway from watching them. She wanted me to ride the train with her, observe people, and talk about why they might be sleepy, whether they were actually getting decent sleep, and what on the train made people prone to sleeping. When I thought about it, I realized we could test this simply by using an ambulatory sleep monitor.
WHY DID YOU SELECT BRANDON FOREMAN AS THE SUBJECT?
I saw Dr. Foreman (one of our neurophysiology fellows) falling asleep in a conference. So I told him what I was planning and he thought it was a cool idea. He told me he was always falling asleep on the subway, and he volunteered to get wired up. My hypothesis was that people rarely got beyond stage 1 and I wanted Brandon to prove it. Well, he proved me wrong!
WHAT WAS THE SET-UP?
We met at the end of a long workweek after Brandon had been up every night dealing with his two-year old son's cold. A tech attached the ambulatory sleep monitor and Brandon covered the wires with a long sock and a winter hat. We boarded on a southbound A train at 207th street, and sat across each other in corner seats. Despite the conductor's shouts on the loudspeakers and the bustle of the 6:09 PM train, I watched him yawn, fold his arms, cross his legs and shut his eyes, opening them only when the train stopped. His head fell after a bit of nodding back and forth, and he dozed from 168th street station to 125th Street. When we reviewed the data, we found that Brandon had slept for 10 minutes out of a 23.5-minute ride. For three and a half minutes, he reached stage 2 level of sleep.
DID ANYONE ON THE SUBWAY WONDER WHAT YOU WERE DOING?
When I observed by myself and with Christine, it wasn't too obvious. What was more interesting was with Brandon: he's wired up all over the head, there's a photographer snapping photos every few seconds, and the reporter and I are watching, taking notes, and whispering. It being New York almost nobody seemed to notice, even on a crowded train. Except the Columbia neuroscientists who were coincidentally on the same train and, when we got off, asked us what we were up to.
HOW MANY MINUTES DOES IT USUALLY TAKE TO REACH STAGE 2 SLEEP?
Usually there is a brief period of stage 1, a few minutes at most, as with Brandon in the article. But there is no question that you can drop directly into stage 2, especially if very sleep deprived.
ARE THERE STUDIES THAT ILLUSTRATE THE RESTORATIVE ASPECTS OF DAYTIME NAPS?
One study, published in Sleep Medicine in 2006, looked at the effects of a 45-minute nap in normal, rested individuals. The nap did result in improved procedural memory, but no improvement in declarative memory or alertness. So there may be some benefit to brief naps, but these by no means make up for a full night of quality sleep.
DAYTIME NAPS ARE SOMETIMES REFERRED TO AS ‘POWER NAPS.’ IS THAT ACCURATE OR IS THAT MERELY A WAY TO JUSTIFY BEING CAUGHT ASLEEP MIDDAY?
A “power nap” — as the study suggests — is a brief period of sleep that can result in memory improvement. While no substitute for a good night's sleep, it likely does improve performance, if you start the day (unavoidably) sleep deprived.
ANY TIPS FOR PEOPLE LIKE ME (WHO CAN'T SEEM TO NAP) ON HOW TO DO SO?
The key aspect of sleep that I think nearly all patients (and probably most physicians) don't adequately acknowledge is: you can't force sleep. You can force eating and drinking to some extent, but not sleep. It is interesting that patients with constipation will go to great lengths to improve this: change in diet, exercise, as well as medication — but with sleep, everyone expects it to work like a switch. I can't tell you how many times I hear: “Doc, just give me something to knock me out.” Well, that's not sleep, that's general anesthesia. And it is most definitely not normal sleep. As for daytime naps: it only works if you can plan for it and take advantage of your natural biorhythms. Typically the best time is midafternoon, when there is a natural sleepiness — that's why siestas occur when they do! A light meal may help, so just after lunch is often ideal. And of course, a quiet comfortable environment, and no caffeine for many hours before. Most of us can't fit all of that into a workday.
Dr. Avitzur, a neurologist in private practice in Tarrytown, NY, holds academic appointments at Yale University School of Medicine and New York Medical College. She is an associate editor of Neurology Today, as well as the editor-in-chief of the AAN Web site, AAN.com, and chair of the AAN Practice Management and Technology Subcommittee.
HOW TO SLEEP ON THE NYC SUBWAY
Brandon Foreman, MD, a fellow in Neurocritical Care/EEG at the Comprehensive Epilepsy Center at the Neurological Institute of New York, has a habit of catching up on his sleep whenever — and wherever — he can. He is currently only four subway stops from the hospital, but until recently had a 30-45 minute commute during which time he often dozed. He generally wakes up revitalized after these mini-naps, (although he noted that the few minutes of sleep during the experiment wasn't the most refreshing); he generally finds that a good 20 minutes or so seems to help.
“When sleeping on subways it's important to keep anything of value inside pockets or bags. Even then, there are some really skilled knife-wielding thieves who can manage to get your things through that too,” he warned.
The day he served as Dr. Bazil's subject, he was more sleep-deprived than usual due to his two-year old son's restless nights from a cold. “I think the majority of the working population in the US is sleep-deprived, but for me at the time, having a sick kid at home didn't help,” he said.
“I maybe got an hour or two less sleep than normal, say five hours rather than the normal six to seven. But that's life.” His son is feeling much better now but Dr. Foreman still wouldn't mind a nice long train ride….
As a future intensivist, Dr. Foreman can't help but wonder if the alarms, room noise, and uncomfortable quarters of the ICU have a similar effect on patients as a busy Manhattan train ride. He's encouraged by the fact that he was able to sleep and hopes that patients are able to do so as well. “We're working to see if we can measure how much sleep our neuro-ICU patients are getting and if we can make it better — more restorative,” he added.
—Dr. Orly Avitzur