Publication of the Association of Polysomnographic Technologists • Summer, 2001 • www.aptweb.org
Sleep Deprivation:
What Conclusions Can Be Drawn?
BY: EDWIN CINTRON, RPSGT, ASSISTANT EDITOR
ne of the more fascinating effects of sleep deprivation is
microsleeps, very powerful forces in which the body cannot resist
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being awake any longer. Defined as short episodes of sleep or catnaps,
they are seen very often in any sleep-deprived person. It usually does not
matter what activity a person is going through. In other words, the force
of sleep becomes so strong that a person can fall asleep while walking,
talking, standing, etc… This proves that when the body, after so many
hours without sleep, automatically shuts down, if only for one second.
That transient episode of sleep would most likely be enough to impair a
person’s ability to concentrate. Microsleeps are a message from the
brain saying that it is time to sleep.
Most experiments show that subjects will also start to hallucinate or
have delusional thoughts. One interesting finding is when Peter Trip, discussed later, was sleep deprived, his brain wave activity was monitored.
During this monitoring it showed that the brain activity was indicative of
a sleeping pattern. That explains why he began to see things that were
not there. His hallucinations most likely came from his brain actually
dreaming while he was awake and communicating.
Mood changes also occur as a direct result of being sleep
deprived. Typical observations include grouchiness, shorter attention
span, fatigue, etc. These occurrences are not necessarily the true
personality of that person. Rather, it is an effect that impairs thought
as the body gets closer to shutting itself down. A thing like the ability
to handle stress becomes a great challenge. Even simple stresses like
looking for a favorite pair of socks may become a great ordeal. Mood
changes seem to only get alleviated when a person finally gets sufficient sleep.
The effects on speech and word fluency become evident after
about thirty hours of staying awake. During the Thurstone Word
Fluency Test (TWFT) people were given a duty of thinking up as many
words as they could in one minute. Without previously knowing what
letter the words start with, the brain is really being put to the test for
spontaneous thinking. When results are compared from being awake
for twelve hours to being awake for thirty-six hours, it is evident that
thought is being impaired. After 36 hours there were more pauses
when thinking up words. The subjects would think of four or five words
then struggle to think up four or five more. Although the effects did
appear practically linear between those two times, the results were
more drastic when kept awake for thirty-six than when kept awake for
twenty hours.
The result of the TWFT can be applied to everyday communication.
When a person no longer has the ability to come up with new ideas, or
new thoughts, keeping up with a conversation would be practically impossible. The longer a person remains awake, the worse their interpersonal skills will become. Not only is the quickness in thought affected, but
the tone and clarity of their speech also shows changes. It will become
softer (to the point of mumbling), and the inability to find new words
causes breaks in the rhythm. The TWFT did more than just how fast a
person can come up with new words, but how sleep deprivation would
affect interpersonal skills and communication.
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Peter Trip had one of the first attempts at long-term sleep deprivation, and is also the subject of one of the more popular experiments
which to compare data. As a New York radio disc jockey, he chose to
stay awake for 200 hours, as a promotion for the March of Dimes,
while running his radio show in its entirety. At the time, two hundred
hours was the world record for sleep deprivation. It was not until
1965 that Randy Gardner broke the record when he stayed awake for
over 260 hours. Many conclusions could be drawn from Trip’s experiment, but in order to draw a true conclusion it must be attempted
again for the sake of science. Any long attempts at sleep deprivation
done more recently are compared to Trip’s experiment because of its
popularity.
In other less popular studies, there were two variations that appear
to improve mental alertness, but when tested found to make little to no
difference. In one sleep deprivation experiment, people were given a
chance to consume caffeine. This technique showed that not even a
stimulant like this would be enough to compensate for lost sleep. A person that would appear to be more alert with caffeine would show no
improvement in overall performance. In another sleep deprivation experiment, people were given a chance to take a thirty-minute nap each day.
The nap did not make their mental alertness better or worse. What it
did was slow the process of decreased performance down. The subjects
getting naps showed some improvement, but not enough to make up for
a full night of lost sleep.
Physical and motor functions appear to go unaffected by long periods of sleep deprivation. In the experiment done on Gardner in 1965,
he was given the opportunity to remain physically active throughout the
experiment. The results showed that although mental alertness decreases, the body still shows a high level of physical potential. Gardner did not
hallucinate the same way that Trip did. Perhaps the physical activity or
exercise had to do with that, but it is yet to be known. Judging by the
data that is available it would appear that besides the inconvenience of
sleep deprivation, there are no long-term effects or physical harm that
can be linked to it.
There are ultimately no proven effects from sleep deprivation, but
there are some aspects that were not investigated. Trip, for example,
after 200 hours of sleep deprivation, appeared to be normal after sleeping 24 consecutive hours. Everyone thought he was unaffected. In the
weeks to come, people that knew him personally noticed a big change in
his personality. He later was fired from his radio station job and divorced
his wife. In another example, involving pilots that were captured in the
Korean War, prisoners of war were tortured by being forced to stay
awake. They too appeared to be unharmed by the long sleep deprivation.
The most likely reason for these effects to not have been documented is
that there was no follow-up evaluation done. In order to find this out scientists would have to follow subjects for weeks, even months, after the
project ended.
During the times that a person is asleep or is supposed to be sleeping, body temperature changes are seen. When a person is awake dur➟
Publication of the Association of Polysomnographic Technologists • Summer, 2001 • www.aptweb.org
ing the hours that they are usually sleeping, their body temperature will
gradually decrease. In an experiment done on rats, Alan Rechtschaffen,
noted sleep researcher at the University of Chicago, showed that these
temperature drops are common in rats. This decline continued until the
result was death of the rats. Normally in sleep, body temperatures will
decline to their lowest point around the same time in every circadian
(24-hour) cycle. The lowest temperature dips usually occur around 4:00
a.m., which is also the time when a person reaches the longest
episodes of REM sleep. Considering this, there is no wonder why Trip
would have his worst hallucinations when his body temperature was at
its lowest point.
Rechtschaffen’s experiments showed that his rats died after about
17 days of staying awake. Although experimentation on animals is the
center of much controversy, it has become more acceptable than the
alternative. Humans are known to have a higher tolerance than rats
when it comes to sleep deprivation; It is estimated that it can take
humans up to seven months of sleep deprivation before dying, however
it would not be unethical to try such experiments on humans. For this
reason alone we may never know exactly what can be concluded from
attempts at total sleep deprivation. With as far as science has come
over the years, there are still many questions that are unanswered
about sleep deprivation. ★
Sleep Arts
Crossword Puzzle
BY DEBBIE AKERS, SPECIAL PROJECTS TEAM, THE A2ZZZ
References
• Culebras, Antonio. Clinical Handbook of Sleep Disorders. Boston: ButterworthHeinemann, 1996.
• Harrison, Yvonne, and James A. Horne. “Sleep Deprivation Affects Speech.” SLEEP 20
(1997): 871-877
• Kreitzer, Stephen. Telephone interview. 24 January 2001.
• Lavie, Peretz. The Enchanted World of Sleep. Trans. Anthony Berris. New Haven and
London: Yale University Press, 1996.
• “The Sleep Files”. Writ. Deborah Colman, Paul Mustafa. Narr. Russ Harris. The Discovery
Channel. New York, 1998.
• Walter Reed Army Institute of Research. Sleep Deprivation and Complex Cognitive
Performance. 07 July 1997. http://wrair-www.army.mil/depts/behavbio/sdccp .htm
• Walter Reed Army Institute of Research. Sleep Deprivation and General Cognitive
Performance. 07 July 1997. http://wrair-www.army.mil/depts/behavbio/sdgcp .htm
• Walter Reed Army Institute of Research. Sleep Deprivation and Simple Psychomotor
Performance, Physical Strength and Endurance. 07 July 1997. http://wrairwww.army.mil/depts/behavbio/sdscp.htm
Down
2. Co-developer of the “Manual of Standardized Terminology, Methodology, and
System for Scoring the Stages of Sleep in Human Subjects”.
3. Developer of the standard approach to the measurement of sleepiness, the MSLT.
5. First to coin the acronym NPT for nocturnal penile tumescence.
6. Co-discoverer of REM.
9. Graduate student of physiology assigned by Kleitman to observe eye movements in the sleeping infant.
10. French collaborator in the discovery of sleep apnea.
13. Current president of the Sleep Research Society.
15. First president of the American Sleep Disorders Association.
16. 1960 author of the first paper documenting sleep onset REM periods in a
single person.
17. Current past president of the APT.
18. Current chairperson for the membership committee of the APT.
Across
Solution on page 27
1. Current editor of The A2Zzz.
4. Current president of the APT.
7. First president of the APT.
8. The first non-clinician to describe the leading sleep disorder of the 20th century.
11. Co-author of The Principles and Practice of Sleep Medicine.
12. Current president of the American Academy of Sleep Medicine.
14. German psychiatrist who in 1928 recorded electrical activity of the human
brain and demonstrated differences in the activity between wake and sleep.
19. In 1974 co-named the all-night diagnostic test. Polysomnography.
20. First to recognize excessive daytime sleepiness as a major presenting complaint.
New APT Products. See Page 29.
Please note that the answers can be referenced to the 1999-2000 Sleep
Directory and the 2nd edition of The Principles and Practice of Sleep Medicine.
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