Typically, mention of our ever
increasing sleeplessness is followed by calls for earlier bedtimes and a
longer night’s sleep. But this directive may be part of the problem. Rather
than helping us to get more rest, the tyranny of the eight-hour block
reinforces a narrow conception of sleep and how we should approach it. Some of
the time we spend tossing and turning may even result from misconceptions about
sleep and our bodily needs: in fact neither our bodies nor our brains are built
for the roughly one-third of our lives that we spend in bed.
The idea that we should sleep
in eight-hour chunks is relatively recent. The world’s population sleeps in
various and surprising ways. Millions of Chinese workers continue to put their
heads on their desks for a nap of an hour or so after lunch, for example, and
daytime napping is common from India
to Spain.
One of the first signs that the
emphasis on a straight eight-hour sleep had outlived its usefulness arose in
the early 1990s, thanks to a history professor at Virginia Tech named A. Roger
Ekirch, who spent hours investigating the history of the night and began to
notice strange references to sleep. A character in the “Canterbury Tales,” for
instance, decides to go back to bed after her “first sleep.” A doctor in England wrote
that the time between the “first sleep” and the “second sleep” was the best
time for study and reflection. And one 16th-century French physician concluded
that laborers were able to conceive more children because they waited until
after their “first sleep” to make love. Professor Ekirch soon learned that he
wasn’t the only one who was on to the historical existence of alternate sleep
cycles. In a fluke of history, Thomas A. Wehr, a psychiatrist then working at
the National Institute of Mental Health in Bethesda, Md.,
was conducting an experiment in which subjects were deprived of artificial
light. Without the illumination and distraction from light bulbs, televisions
or computers, the subjects slept through the night, at least at first. But,
after a while, Dr. Wehr noticed that subjects began to wake up a little after
midnight, lie awake for a couple of hours, and then drift back to sleep again,
in the same pattern of segmented sleep that Professor Ekirch saw referenced in
historical records and early works of literature.
It seemed that, given a chance
to be free of modern life, the body would naturally settle into a split sleep
schedule. Subjects grew to like experiencing nighttime in a new way. Once they
broke their conception of what form sleep should come in, they looked forward
to the time in the middle of the night as a chance for deep thinking of all
kinds, whether in the form of self-reflection, getting a jump on the next day
or amorous activity. Most of us, however, do not treat middle-of-the-night
awakenings as a sign of a normal, functioning brain.
Doctors who peddle sleep aid
products and call for more sleep may unintentionally reinforce the idea that
there is something wrong or off-kilter about interrupted sleep cycles. Sleep
anxiety is a common result: we know we should be getting a good night’s rest
but imagine we are doing something wrong if we awaken in the middle of the
night. Related worries turn many of us into insomniacs and incite many to reach
for sleeping pills or sleep aids, which reinforces a cycle that the Harvard
psychologist Daniel M. Wegner has called “the ironic processes of mental
control.”
As we lie in our beds thinking
about the sleep we’re not getting, we diminish the chances of enjoying a
peaceful night’s rest.
This, despite the fact that a
number of recent studies suggest that any deep sleep — whether in an eight-hour
block or a 30-minute nap — primes our brains to function at a higher level,
letting us come up with better ideas, find solutions to puzzles more quickly,
identify patterns faster and recall information more accurately. In a
NASA-financed study, for example, a team of researchers led by David F. Dinges,
a professor at the University of Pennsylvania, found that letting subjects nap
for as little as 24 minutes improved their cognitive performance.
In another study conducted by
Simon Durrant, a professor at the University
of Lincoln, in England, the
amount of time a subject spent in deep sleep during a nap predicted his or her later
performance at recalling a short burst of melodic tones. And researchers at the
City University of New York found that short naps helped subjects identify more
literal and figurative connections between objects than those who simply stayed
awake.
Robert Stickgold, a professor
of psychiatry at Harvard
Medical School,
proposes that sleep — including short naps that include deep sleep — offers our
brains the chance to decide what new information to keep and what to toss. That
could be one reason our dreams are laden with strange plots and characters, a
result of the brain’s trying to find connections between what it’s recently
learned and what is stored in our long-term memory.
Rapid eye movement sleep — so named because researchers who discovered this sleep
stage were astonished to see the fluttering eyelids of sleeping subjects — is
the only phase of sleep during which the brain is as active as it is when we
are fully conscious, and seems to offer our brains the best chance to come up
with new ideas and hone recently acquired skills. When we awaken, our minds are
often better able to make connections that were hidden in the jumble of
information.
Gradual acceptance of the
notion that sequential sleep hours are not essential for high-level job
performance has led to increased workplace tolerance for napping and other
alternate daily schedules.
Employees at Google, for
instance, are offered the chance to nap at work because the company believes it
may increase productivity. Thomas Balkin, the head of the department of
behavioral biology at the Walter Reed Army Institute of Research, imagines a
near future in which military commanders can know how much total sleep an
individual soldier has had over a 24-hour time frame thanks to wristwatch-size
sleep monitors. After consulting computer models that predict how
decision-making abilities decline with fatigue, a soldier could then be ordered
to take a nap to prepare for an approaching mission. The cognitive benefit of a
nap could last anywhere from one to three hours, depending on what stage of
sleep a person reaches before awakening.
Most of us are not fortunate
enough to work in office environments that permit, much less smile upon,
on-the-job napping. But there are increasing suggestions that greater tolerance
for altered sleep schedules might be in our collective interest. Researchers
have observed, for example, that long-haul pilots who sleep during flights
perform better when maneuvering aircraft through the critical stages of descent
and landing.
Several Major League Baseball
teams have adapted to the demands of a long season by changing their sleep
patterns. Fernando Montes, the former strength and conditioning coach for the
Texas Rangers, counseled his players to fall asleep with the curtains in their hotel
rooms open so that they would naturally wake up at sunrise no matter what time
zone they were in — even if it meant cutting into an eight-hour sleeping block.
Once they arrived at the ballpark, Montes would set up a quiet area where they
could sleep before the game. Players said that, thanks to this schedule, they
felt great both physically and mentally over the long haul.
Strategic napping in the
Rangers style could benefit us all. No one argues that sleep is not essential.
But freeing ourselves from needlessly rigid and quite possibly outdated ideas
about what constitutes a good night’s sleep might help put many of us to rest,
in a healthy and productive, if not eight-hour long, block.
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* David K. Randall is a senior
reporter at Reuters and the author of
“Dreamland: Adventures in the Strange Science of Sleep.”
