Polyphasic sleep
Encyclopedia
Polyphasic sleep, a term coined by early 20th-century psychologist J.S. Szymanski, refers to the practice of sleep
Sleep
Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than...

ing multiple times in a 24-hour period—usually more than two, in contrast to biphasic sleep (twice per day) or monophasic sleep (once per day). It does not imply any particular sleep schedule. The circadian rhythm
Circadian rhythm
A circadian rhythm, popularly referred to as body clock, is an endogenously driven , roughly 24-hour cycle in biochemical, physiological, or behavioural processes. Circadian rhythms have been widely observed in plants, animals, fungi and cyanobacteria...

 disorder known as irregular sleep-wake syndrome is an example of polyphasic sleep in humans. Polyphasic sleep is common in many animals, and is believed to be the ancestral sleep state. The term polyphasic sleep, or often Uberman's sleep schedule, is also used by an online community which experiments with ultra-short napping to achieve more time awake each day.

Multiphasic sleep of normal total duration

An example of polyphasic sleep is found in patients with irregular sleep-wake syndrome, a circadian rhythm sleep disorder
Circadian rhythm sleep disorder
Circadian rhythm sleep disorders are a family of sleep disorders affecting, among other things, the timing of sleep. People with circadian rhythm sleep disorders are unable to sleep and wake at the times required for normal work, school, and social needs. They are generally able to get enough sleep...

 which usually is caused by head injury or dementia
Dementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...

. Much more common examples are the sleep of human infants and of many animals. Elderly humans often have disturbed sleep, including polyphasic sleep.

In their 2006 paper "The Nature of Spontaneous Sleep Across Adulthood," Campbell and Murphy studied sleep timing and quality in young, middle-aged and older adults. They found that, in freerunning conditions, the average duration of major nighttime sleep was significantly longer in young adults than in the other groups. The paper states further:

Napping in extreme situations

In crises and other extreme conditions, people may not be able to achieve the recommended eight hours of sleep per day. Systematic napping may be considered necessary in such situations.

Dr. Claudio Stampi
Claudio Stampi
Dr. Claudio Stampi is the founder , director and sole proprietor of the Chronobiology Research Institute which he runs from his home in Newton, Massachusetts. He is a researcher of the use of short naps in extreme conditions...

, as a result of his interest in long-distance solo boat racing
Boat racing
-Types:* Canoe racing, competitive forms of canoeing and kayaking* Drag boat racing, a form of drag racing which takes place on water rather than land* Dragon boat racing, a type of human-powered watercraft racing...

, has studied the systematic timing of short naps as a means of ensuring optimal performance in situations where extreme sleep deprivation is inevitable, but he does not advocate ultrashort napping as a lifestyle. Scientific American Frontiers
Scientific American Frontiers
Scientific American Frontiers was an American television program primarily focused on informing the public about new technologies and discoveries in science and medicine. It was a companion program to the Scientific American magazine. The show was produced for PBS in the U.S...

(PBS
Public Broadcasting Service
The Public Broadcasting Service is an American non-profit public broadcasting television network with 354 member TV stations in the United States which hold collective ownership. Its headquarters is in Arlington, Virginia....

) has reported on Stampi's 49-day experiment where a young man napped for a total of three hours per day. It purportedly shows that all stages of sleep were included. Stampi has written about his research in his book Why We Nap: Evolution, Chronobiology, and Functions of Polyphasic and Ultrashort Sleep (1992). In 1989 he published results of a field study in the journal Work & Stress, concluding that "polyphasic sleep strategies improve prolonged sustained performance" under continuous work situations.

The U.S. military

The U.S. military
United States armed forces
The United States Armed Forces are the military forces of the United States. They consist of the Army, Navy, Marine Corps, Air Force, and Coast Guard.The United States has a strong tradition of civilian control of the military...

 has studied fatigue countermeasures. An Air Force report states:

The Canadian Marine Pilots

Similarly, the Canadian Marine Pilots in their trainer's handbook report that:

NASA

NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

, in cooperation with the National Space Biomedical Research Institute, has funded research on napping. Despite NASA recommendations that astronaut
Astronaut
An astronaut or cosmonaut is a person trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft....

s sleep 8 hours a day when in space, they usually have trouble sleeping 8 hours at a stretch, so the agency needs to know about the optimal length, timing and effect of naps. Professor David Dinges
David F. Dinges
David F. Dinges is a major American sleep researcher and teacher.He is Professor of Psychology in Psychiatry, Chief of the Division of Sleep and Chronobiology in the Department of Psychiatry, and Associate Director of the Center for Sleep and Respiratory Neurobiology in the University of...

 of the University of Pennsylvania School of Medicine
University of Pennsylvania School of Medicine
The Perelman School of Medicine , formerly the University of Pennsylvania School of Medicine, was founded in 1765, making it the oldest American medical school. As part of the University of Pennsylvania, it is located in the University City section of Philadelphia, Pennsylvania. It is widely...

 led research in a laboratory setting on sleep schedules which combined various amounts of "anchor sleep," ranging from about 4 to 8 hours in length, with no nap or daily naps of up to 2.5 hours. Longer naps were found to be better, with some cognitive functions benefiting more from napping than others. Vigilance and basic alertness benefited the least while working memory
Working memory
Working memory has been defined as the system which actively holds information in the mind to do verbal and nonverbal tasks such as reasoning and comprehension, and to make it available for further information processing...

 benefited greatly. Naps in the individual subjects' biological daytime worked well, but naps in their nighttime were followed by much greater sleep inertia
Sleep inertia
Sleep inertia is a physiological state characterised by a decline in motor dexterity and a subjective feeling of grogginess immediately following an abrupt awakening. The impaired alertness may interfere with the ability to perform mental or physical tasks...

 lasting up to an hour.

The Italian Air Force

The Italian Air Force (Aeronautica Militare Italiana) also conducted experiments for their pilots. In schedules involving night shifts and fragmentation of duty periods through the entire day, a sort of polyphasic sleeping schedule was studied. Subjects were to perform four hours of activity followed by two hours of rest (sleep allowed), this was repeated four times throughout the 24-hour day. Although sleep was allowed, subjects adopted a schedule of not sleeping at all during the first rest period of the day. The AMI published findings that "total sleep time was substantially reduced as compared to the usual 7–8 hour monophasic nocturnal sleep" while "maintaining good levels of vigilance as shown by the virtual absence of EEG microsleeps." EEG microsleep
Microsleep
A microsleep is an episode of sleep which may last for a fraction of a second or up to thirty seconds. Often, it is the result of sleep deprivation, mental fatigue, depression, sleep apnea, hypoxia, narcolepsy, or hypersomnia...

s are measurable and usually unnoticeable bursts of sleep in the brain while a subject appears to be awake. Nocturnal sleepers who sleep poorly may be heavily bombarded with microsleeps during waking hours, limiting focus and attention.

Historically

Before the advent of electric lighting in Europe, sleepers awoke from their "first" sleep for an hour or more during the night, before returning to their "second" sleep.

Biphasic sleep studies

One study suggests that during periods of short daylight (~10 hours, as in winter), humans will adopt a biphasic sleep pattern. Another study indicates that this will happen whenever humans are removed from artificial light.

Scheduled napping to achieve more time awake

In an early mention of systematic napping as a lifestyle, in order to gain more time awake in the day, Buckminster Fuller
Buckminster Fuller
Richard Buckminster “Bucky” Fuller was an American systems theorist, author, designer, inventor, futurist and second president of Mensa International, the high IQ society....

 reportedly advocated a regimen consisting of 30-minute naps every six hours. The short article about Fuller's nap schedule in Time
Time (magazine)
Time is an American news magazine. A European edition is published from London. Time Europe covers the Middle East, Africa and, since 2003, Latin America. An Asian edition is based in Hong Kong...

in 1943, which also refers to such a schedule as "intermittent sleeping," says that he maintained it for two years, and further notes:
However, it is not clear when Fuller practiced any such sleep pattern, and whether it was really as strictly periodic as claimed in that article; it has also been said that he ended this experiment because of his wife's objections. Moreover, Fuller is the only figure on record who claimed a successful Dymaxion
Dymaxion
The word Dymaxion is a brand name that Buckminster Fuller used for several of his inventions. It is a portmanteau of the words dynamic, maximum, and ion....

 sleep. Thus, there is no certitude about the sustainability of this schedule.

Critics such as psychologist and software entrepreneur Piotr Woźniak
Piotr Wozniak (researcher)
Piotr A. Woźniak is the principal author of SuperMemo and a researcher in the theory of spaced repetition.-Partial bibliography:Academic articles he has authored include:...

 consider the theory behind severe reduction of total sleep time by way of short naps unsound, claiming that there is no brain control mechanism that would make it possible to adapt to the "multiple naps" system. They say that the body will always tend to consolidate sleep into at least one solid block, and they express concern that the ways in which the ultrashort nappers attempt to limit total sleep time, restrict time spent in the various stages of the sleep cycle, and disrupt their circadian rhythms, will eventually cause them to suffer the same negative effects as those with other forms of sleep deprivation
Sleep deprivation
Sleep deprivation is the condition of not having enough sleep; it can be either chronic or acute. A chronic sleep-restricted state can cause fatigue, daytime sleepiness, clumsiness and weight loss or weight gain. It adversely affects the brain and cognitive function. Few studies have compared the...

 and circadian rhythm sleep disorder
Circadian rhythm sleep disorder
Circadian rhythm sleep disorders are a family of sleep disorders affecting, among other things, the timing of sleep. People with circadian rhythm sleep disorders are unable to sleep and wake at the times required for normal work, school, and social needs. They are generally able to get enough sleep...

s, such as decreased mental and physical ability, increased stress and anxiety, and a weakened immune system. Woźniak further claims to have scanned the blogs of polyphasic sleepers and found that they have to choose an "engaging activity" again and again just to stay awake and that polyphasic sleep does not improve one's learning ability or creativity.

Comparison of sleep patterns

Name Total sleeping time Method
Monophasic ≈8.0 h 8 hours major sleep episode.
Biphasic ≈6.3 h 6 hours major sleep episode and one twenty-minute power nap
Power nap
A power nap is a short sleep which terminates before the occurrence of deep sleep or slow-wave sleep , intended to quickly revitalize the subject. The expression was coined by Cornell University social psychologist James Maas.-Characteristics:...

.
Biphasic (90-minute nap) 6 h 4.5 hours major sleep episode and one ninety-minute nap.
Everyman (with 2 naps) 5.2 h 4.5 hours major sleep episode and two twenty-minute power naps.
Everyman (with 3 naps) 4 h 3 hours major sleep episode and three twenty-minute power naps.
Everyman (with 4 - 5 naps) ≈3 h 1.5 hours major sleep episode and four to five twenty-minute power naps.
Dymaxion
Dymaxion
The word Dymaxion is a brand name that Buckminster Fuller used for several of his inventions. It is a portmanteau of the words dynamic, maximum, and ion....

2 h Four 30-minute naps (every 6 hours).
Uberman (from German 'Übermensch
Übermensch
The Übermensch is a concept in the philosophy of Friedrich Nietzsche. Nietzsche posited the Übermensch as a goal for humanity to set for itself in his 1883 book Thus Spoke Zarathustra ....

')
2 h Six twenty-minute naps (every 4 hours).

External links

  • Polyphasic Sleep: Facts and Myths – Dr. Piotr Wozniak – January 2005 – This article compares polyphasic sleep to regular monophasic sleep, biphasic sleep, as well as to the concept of free-running sleep.
  • Miles to Go Before I Sleep at Outside.com, April 2005.
  • Poly-phasers – an online polyphasic community with an active IRC channel, blogs, videos and articles
  • TryPolyphasic.com – an active online polyphasic community, includes a map of world wide polyphasers
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK