Sleep paralysis

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Sleep paralysis is a condition characterized by temporary paralysis of the body shortly after waking up (known as hypnopompic paralysis) or, less often, shortly before falling asleep (known as hypnagogic paralysis).

The Nightmare, by Henry Fuseli (1781) is thought to be one of the classic depictions of sleep paralysis perceived as a demonic visitation.

Physiologically, it is closely related to the normal paralysis that occurs during REM (rapid eye movement) sleep, also known as REM atonia. In that, some scientists and physicians believe it to be a "natural" effect of the sleep cycle. Sleep paralysis occurs when the brain is awakened from a REM state into essentially a normal fully awake state, but the bodily paralysis is still occurring. This causes the person to be fully aware, but unable to move. In addition, this state may be accompanied by hypnagogic hallucinations.

More often than not, sleep paralysis is believed by the person affected by it to be no more than a dream. This is the reason why there are many dream recountings which describe the person lying frozen and unable to move. The hallucinatory element to sleep paralysis makes it even more likely that someone will interpret the experience as simply a dream, as one might see completely fanciful objects in a room alongside the normal vision one can see.

[edit] Symptoms

The primary symptom of sleep paralysis is partial or complete skeletal muscle paralysis during the hypnopompic or hypnagogic states. In other words, it is the sense of being aware that one is unable to move or speak while falling asleep or waking up. Sleep paralysis may also be accompanied by hypnagogic hallucinations.^[1] These hallucinations can be auditory, tactile, and/or visual. If a polysomnograph is taken, at least one of the following will be shown: skeletal muscle tone suppression, REM sleep at sleep onset, or dissociated REM sleep. The sleep paralysis persists anywhere from a few seconds to a few minutes ^[1] before the person is able to either return to REM sleep or to become fully awake.

[edit] Possible causes

Sleep paralysis occurs during REM sleep in order to prevent the body from manifesting movements made in the subject's dreams. Little is known about the physiology of sleep paralysis. However, some have suggested that it may be linked to post-synaptic inhibition of motor neurons in the pons region of the brain. In particular, low levels of melatonin may stop the depolarization current in the nerves, which prevents the stimulation of the muscles, to prevent the body from enacting the dreamt activity (e.g. preventing a sleeper from flailing his legs when dreaming about running).

Many people who commonly enter sleep paralysis also suffer from narcolepsy. However, various studies suggest that many or most people will experience sleep paralysis at least once or twice in their lives.

Some reports read that various factors increase the likelihood of both paralysis and hallucinations. These include: ^[2]

• Sleeping in a supine position (facing upwards)
• Irregular sleeping schedules; naps, sleeping in, sleep deprivation
• Increased stress
• Sudden environmental/lifestyle changes
• A lucid dream that immediately precedes the episode. Also conscious induction of sleep paralysis is a common technique to enter a state of lucid dreams, also known as WILD[1] .
• Artificial sleeping aids, ADD medications and/or antihistamines

[edit] Cultural references

• In Chinese folk culture, sleep paralysis is referred as "gǔi yà chúang" (鬼压床,鬼壓床), literally: "Ghost press bed": 鬼: ghost, 压: press, 床: bed. The belief is that a spirit or ghost is sitting or lying on top of the sleeping individual, causing the sleep paralysis. This is thought to be a minor body possession by the forces from the dead, and usually doesn't cause any harm to the victim.
• In Japan, sleep paralysis is referred to as kanashibari (金縛り, literally "bound or fastened in metal," from kane "metal" and shibaru "to bind, to tie, to fasten").
• In Thailand, this condition is said to be caused by a spirit or "pee um" (ผีอำ) which sits or lie atop of the victim causing him or her to be immobile. The spirit causes no harm to the victim and is said to only be playing pranks.
• In Scandanavian mythology, sleep paralysis was caused by a Mara, or mare - a kind of malignant female wraith who can also cause nightmares. She appears as early as in the Norse Ynglinga saga, but the belief itself is probably even older. "Mara" is the Old Norse, Swedish and Icelandic name, "mare" is Norwegian and Danish.
• In Newfoundland, as a visit from the "old hag" (Irish: Ag Rog).
• In Mexico, as subida del muerto (the dead climbing on top).
• In Greek, as mora (in Greek: μώρα), the name has a Slavic root.
• In German as Hexendrücken (witch pressing).
• In Turkish, as karabasan (literally: "dark presser": kara: "dark/black":, basan: "pusher, presser". Most Turkish people believe that it's a metaphysical incident, and especially religious people believe that it's a jini that causes the uncomfort; so generally some kind of prayer is advised).
• In Hazaragi, as Syahi Zer Kado (pressing ink).
• In the Southern United States, people have described it as "The witch riding your back".
• In the Western United States, the Sleep Paralysis is commonly called "Scissor Lock".
• In Korea, it is referred as Gawinullim, (가위눌림) literally in English: "To be pressed by Gawi." The meaning of Gawi is clear, generally known to mean "spirits" or "demons." Another word in Korean "Gawi" is a homonym that means "scissors". Such occurrences are usually referenced as "scissor lock" in English.^{[citation needed]}
• In Indonesia, Javanese people call it tindihan, spelled traditionally as "tindhihen" (To be laid upon). Also in Sundanese, people call it ereup-ereup.
• In the Philippines, Sleep paralysis is often associated with Bangungot.
• In Malaysia, known as "kena himpap", meaning being pressed down.
• In Vietnam, sleep paralysis is known as "ma đè", meaning a ghost or spirit lying on top of or pressing down on the person.
• In the West Indies, being "ridden by a duppy".
• In medieval times of Europe, attacks of sleep paralysis may have given rise to the belief in mara, incubi, succubi, other demons and witchcraft. People in England believed that witches or hags rode on men's chests as they slept, and the feeling of being unable to breathe was attributed to a hag. This is why people who have had very little sleep may be described as looking "hag-ridden".
• In traditional Russian belief symptoms reminiscent of sleep paralysis were attributed to the anger of domovoi, the home spirit, punishing people for bad husbandship or betrayal.
• According to traditional Hmong beliefs, various states of sleep paralysis are thought to be the processes in which an evil spirit or demon sits down on a person usually in retaliation to wrongdoings. Some Hmong have deemed it as the process of getting 'squashed'.
• Traditional Islamic cultures would usually interpret this as an encounter with a Jinn (or "djinn"); a race of beings, similar to humans which inhabit the earth. The word "jinn" literally means anything which has the connotation of concealment, invisibility, seclusion and remoteness, and is one of the two beings (the other being Human) addressed directly in the Quran. In Islamic text, and scholarship, Jinns are considered beings, which like humans are accountable for their deeds and thus have free will. They are considered to have life and death, society, culture and religion.
• In Laotian culture, it is called "pee um" translated as "ghost silencing you". The ghost or spirit is thought to visit you in the night, hold your arms and legs down, and even cover your mouth up so that no sound would come out when you scream.
• In Finnish a nightmare is called painajainen, but literally it means "pressing" and is thought to be originating from sleep paralysis sensory effects.
• In Hungarian folk culture sleep paralysis is called "lidércnyomás" ("lidérc pressing") and can be attributed to a number of supernatural entities like "lidérc", "boszorkány" (witch), "tündér" (fairy) or "ördögszerető".^[3] The word "boszorkány" itself stems from the turkish root "basz-", meaning "to press".^[4]
• New-age practitioners have argued that sleep paralysis might be the point of separation of the "dream body" from the physical body and out-of-body travel then begins.
• Scientists believe that many supposed occurrences of alien abduction, out-of-body travel, and other seemingly paranormal events may actually be due to misinterpreting the sensory effects of sleep paralysis.

[edit] Sleep paralysis in literature and art

There is a particularly fascinating account of sleep paralysis in Herman Melville's novel Moby-Dick. Chapter 4 (The Counterpane) is an account of Ishmael's meditation on an episode of sleep paralysis in the middle of which he could not distinguish the difference between Queequeg's arm and the quilt. Indeed, he could not even distinguish the difference between his own body and his surroundings. He then recalls an earlier episode of sleep paralysis from his childhood, which he determines was the precise moment he discovered the feeling of "otherness" of his own body with respect to his surroundings.

An account can also be found in Ernest Hemingway's The Snows of Kilimanjaro, in which death approaches and sits upon the narrator's chest so that he cannot breathe.

The musical group dredg put out an album called El Cielo dealing with sleep paralysis. A good portion of the lyrics on the album are taken directly from letters by people describing their experiences with sleep paralysis. The song which most directly deals with the subject is called "Scissor Lock".

Experimental band Fear Before the March of Flames talk about the struggles of dealing with constant sleep paralysis on their new album "The Always Open Mouth". One of the songs is even called "Drowning the Old Hag"

[edit] See also

• Hypnagogic hallucinations
• Rapid eye movement (REM)
• Sleep
• Night terror
• Nightmare
• False awakening
• Lucid dreaming

[edit] Notes

1. ^ ^{a b} J. A. Cheyne. Sleep Paralysis and Associated Hypnagogic and Hypnopompic Experiences. Retrieved on 17 July, 2006.
2. ^ J. A. Cheyne. Preventing and Coping with Sleep Paralysis. Retrieved on 17 July, 2006.
3. ^ lidérc, Magyar Néprajzi Lexikon, Akadémiai Kiadó, Budapest 1977, ISBN
4. ^ boszorkány, Magyar Néprajzi Lexikon, Akadémiai Kiadó, Budapest 1977, ISBN

[edit] References

• Bower, Bruce (July 9, 2005). "Night of the Crusher." Science News.
• Conesa, J. (2000). Geomagnetic, cross-cultural and occupational faces of sleep paralysis: An ecological perspective. Sleep and Hypnosis, 2, (3), 105-111.
• Conesa, J. (2002). Isolated Sleep Paralysis and Lucid Dreaming: Ten-year longitudinal case study and related dream frequencies, types, and categories. Sleep and Hypnosis, 4, (4), 132-143.
• Conesa, J. (2003). Sleep Paralysis Signaling (SPS) As A Natural Cueing Method for the Generation and Maintenance of Lucid Dreaming. Presented at The 83rd Annual Convention of the Western Psychological Association, May 1 - 4, 2003 in Vancouver, BC, Canada.
• Conesa-Sevilla, Jorge (2004). Wrestling With Ghosts: A Personal and Scientific Account of Sleep Paralysis. Pennsylvania: Xlibris/Randomhouse.
• Firestone K. The “Old Hag”: sleep paralysis in Newfoundland. The Journal of Psychoanalytic Anthropology 1985; 8:47-66.
• Fukuda K, Miyasita A, Inugami M, Ishihara K. High prevalence of isolated sleep paralysis: kanashibari phenomenon in Japan. Sleep 1987; 10:279-286.
• Hartmann E. The nightmare: the psychology and biology of terrifying dreams. New York:Basic,1984.
• Hufford D.J. The terror that comes in the night: an experience-centered study of supernatural assault traditions. Philadelphia:University of Pennsylvania Press, 1982
• Kettlewell, N; Lipscomb, S; Evans, E. (June, 1993). "Differences in neuropsychological correlates between normals and those experiencing "Old Hag Attacks'." Perceptual and Motor Skills. 76 (3 Pt 1): 839-45; discussion 846. PMID 8321596
• Ness RC. “The Old Hag” phenomenon as sleep paralysis: a bicultural interpretation . Culture, Medicine and Psychiatry 1978; 2:15-39.
• Ohayon MM, Zulley J, Guilleminault C, Smirne, S. Prevalence and pathologic associations of sleep paralysis in the general population. Neurology, 1999; 52:1194-1200.
• Sagan, Carl (1997). The Demon-Haunted World: Science as a Candle in the Dark.
• Schneck JM. Sleep paralysis and microsomatognosia with special reference to hypnotherapy . The International Journal of Clinical and Experimental Hypnosis 1977; XXV:72-77.
• Takeuchi T, Miyasita A, Sasaki Y, Inugami M, Fukuda K. Isolated sleep paralysis elicited by sleep interruption. American Sleep Disorders Association and Sleep Research Society, 1992; 15: 217-225.

[edit] External links

• Sleep Paralysis Information Service
• Susan Blackmore on sleep paralysis
• Projective Catalepsy: Out-of-Body Experience & Sleep Paralysis by International Academy of Consciousness
• The Skeptic's Dictionary entry on Sleep Paralysis
• Sleep paralysis at Here Be Dreams
• Sleep information and links from Stanford University
• Sleep Paralysis and Associated Hypnagogic and Hypnopompic Experiences from University of Waterloo
• Abduction by Aliens or Sleep Paralysis? - Skeptical Inquirer magazine, May/June 1998
• How to Cope with Sleep Paralysis
• Sleep Paralysis and Lucid Dreaming Jorge Conesa on Sleep Paralysis
• Waking Up to Sleep Paralysis