Understanding Sleep Paralysis

Imagine waking up in the dark only to find that you are completely unable to move, unable to speak, and all the while there is the sensation that something is sitting on top of you. The very concept of this seems terrifying at the very least, and it sounds like something completely out of a horror film, but it is actually a very realistic occurrence that certain individuals experience. Sleep paralysis has been studied substantially over the past several decades since its original diagnoses, as the experience is likely to be as stressful on the body as the factors that influence it. Previously associated with witchcraft and supernatural components, the condition also has equally strong connections to nightmares and an emotional context as it does through anxiety disorders, depression, and biological abnormalities in the brain. This paper will explore the numerous factors that play into both the development of sleep paralysis and the things that result from it. Especially in the last decade, many articles have been published on sleep paralysis as it becomes less of a bizarre phenomenon and more of a curable condition. By examining these articles, the ultimate goal will be to understand that sleep paralysis is not a thing to fear occurring, but rather another condition that can be prevented by proper care for the body.

A rather contemporary condition, having only been truly discovered over the past fifty years, it is defined that “sleep paralysis is a transient, generalized inability to move or speak that usually seen during the patient’s transitions between sleeping and wakefulness.” (Nair et al. 2013) Of course the European supernatural roots that the condition stems from were most likely brought upon by the sensation that something else is in the room or even on top of the patient. It is often experienced after nightmares and “the ‘mare’ element of the English ‘nightmare’ derives from the same root as the Germanic mahr and Old Norse mara, a supernatural being, usually female, who lay on people’s chests at night, thereby suffocating them.” (Davies 2003, p. 183) Furthermore, people dealing with sleep paralysis have even been known to see individuals in the room with them while it is occurring. These other symptoms are interesting because they cannot easily be explained by the factors that influence sleep paralysis or the condition itself. To this day, very little is clearly understood and defined regarding sleep paralysis; there is nothing that creates a direct causation that can cure chronic suffers from their situation. One thing that researchers have noted is that “SP experiencers are chronically sleep-deprived and may have relatively high nocturnal arousal levels related to shallow circadian fluctuations such as those observed in narcolepsy.” (Girard and Cheyne 2006, p. 228) So, research has been able to define correlations that help find preventative measures for sleep paralysis, yet nothing that tells patients how to avoid it altogether. Furthermore, “Hsieh et al (2010) demonstrated that ISP was independently associated with excessive daytime sleepiness, worse sleep quality, and impaired mental health-related quality of life in their Chinese-Taiwanese subjects,” (Nair et al. 2013) so findings among this particular population may help make greater generalizations about the condition altogether. One hypothesis is that “subjective features of sleep paralysis with hypnagogic hallucinations could be derived from its innate physiological process.” (Fukuda 2006, p. 167) With this in mind, one school in examining sleep paralysis may be to focus more on the brain and the theories behind hallucinations and less on the actual biological processes that occur. One particular form of sleep paralysis that has been examined more extensively is isolated sleep paralysis (ISP), which is where the occurrence happens on a singular occasion and isn’t directly linked to other episodes. Much akin to the original concepts of sleep paralysis, it is noted that “ISP is a part of the mythology of certain cultures and has been attributed to supernatural forces such as ghost oppression phenomenon in Hong Kong Chinese witchcraft.” (Nair et al. 2013) So it is interesting that the supernatural trend occurs in Asia as well, because this idea of witchcraft connects it to the European origins, creating a cross-cultural effect that can be recognized by a wide group of individuals.

While much of sleep paralysis is studied in the field of psychology, making most of it conceptual and based in theory, there have been discoveries made as to the specific brain occurrence that happen with the condition. It is noted that “SP is generally considered to be a rapid eye movement (REM)-related phenomenon with experimental evidence of SP occurring during sleep-onset REM periods.” (Girard and Cheyne 2006, p. 222) This would make a strong case for the connection that sleep paralysis has to the occurrence of nightmares, both the classic and modern understanding of them. Since REM stages are when dreams occur, then particularly negative dreams would be associated with these nightmares, and it would be more interesting to understand the direct correlation that types of dreams have to the onset of sleep paralysis. What particular brain activity occurs during a nightmare that may have a causal affect on sleep paralysis? Deepa Nair and her colleagues (2013) provide some basic insight in a fairly recent study conducted research that linked sleep paralysis to anxiety, something that likely occurs during the onset of nightmares. In their findings, they highlighted that “the episodes in ISP are more likely to occur during awakening from sleep (hypnopompic) while episodes of narcolepsy associated sleep paralysis tend to occur commonly during sleep onset (hypnagogic)” (Nair et al. 2013) The sleep paralysis that would be, if at all, linked to nightmares would then be hypnagogic. This is then also linked to the hypnagogic hallucinations and the “innate physiological process” highlighted earlier by Fukuda. If these processes are innate, then does that mean that sleep paralysis is either genetic or sociological induced? Perhaps further research on sleep paralysis will open up points in the classic nature v. nurture debate.

Another element of sleep paralysis is the emotions that it brings up during the experience. For obvious reasons, many can understand that there is a tendency for the emotions to be negative, given the previously addressed connection to nightmares. Again, Kazuhiko Fukuda brings up many interesting connections with sleep paralysis, connecting them to an emotional context that can either inspire the onset of sleep paralysis, or be a result of it. He generally summarizes this idea by pointing out how “symptoms reported during sleep paralysis and hypnagogic hallucinations could be summarized into three categories: ‘intruder’, ‘incubus’, and ‘unusual bodily experiences.’”(Fukuda 2006, p. 166) All of these, in any situation, would strike fear in an individual and increase levels of stress, since they all represent something that is both unfamiliar and highly dangerous. Because of this, certain theories that link fear to the original concept of nightmares and contemporary sleep paralysis begin to take shape. Here is the foundational hypothesis that can be drawn about sleep paralysis, nightmares, and these emotions: if sleep paralysis is linked to nightmares, and nightmares are often linked with feelings of fear and anxiety, then sleep paralysis will be linked to feelings of fear and anxiety. Fukuda supports this hypothesis when talking about the biological processes of the brain and the amygdala, discussing how “through these processes, the amygdaloid complex gives some biologically significant valence to the stimuli, in other words, it is a critical structure for processing biologically relevant stimuli, particularly those that signal fear.” (Fukuda 2006, p. 166) So through his findings, it can be supported that the processes that spark a case of (usually) isolated sleep paralysis are usually part of the processing of fear, so that fear stimulates sleep paralysis. He also notes that “the majority of people suffering from sleep paralysis seem to find themselves in a supine position during the episodes.” (Fukuda 2006, p. 167) There isn’t a great deal of understanding as to what biologically causes this relationship, however, in both a psychological and symbolic context, the supine position often creates feelings of vulnerability, since the chest and heart are physically exposed. This vulnerability can amplify the feelings of fear and anxiety. Furthermore, it has been historically understood that “the relationship between the supine position and ‘nightmares’ has been suggested by many folklore beliefs. Until the nineteenth century, the concept of ‘nightmare’ included sleep paralysis and several other bizarre phenomena occurring at night.” (Fukuda 2006, p. 167) So, we can historically believe that sleep paralysis has always had a link to nightmares, since it is the paralysis that defined a nightmare in the first place. This further supports our own hypothesis that fear and anxiety are linked to sleep paralysis, since it is a foundational part of the nightmares that are often incited by these emotions. Biologically, it is noted that “amygdaloid activation, which is inferred from the results of brain imaging research on usual REM sleep, initiates the experience of the “intruder” through the production of a hyper vigilant state (Fukuda 2006, p. 167) So, not only does Fukuda give a conceptual understanding as to how we can link sleep paralysis with these feelings of fear and anxiety, but he also more clearly defines the biological, tangible evidence that supports this hypothesis that has been created.

To conclude, there is a lot of information that has yet to be discovered about sleep paralysis. This is mainly due to the fact that the actual scientific classification of this disorder is still very contemporary and new, in spite of the historical, albeit “supernatural,” context that the disorder stems from. Yet the most important thing to not is that the condition is not something to fear, regardless of the feelings of fear and anxiety that is it linked to. Rather, sleep paralysis is something that can be prevented by ensuring that an individual is getting the proper amount of sleep, or at the very least never being too sleep deprived. As further research continues, more direct correlations are likely to be developed, empowering patients to literally “rest easy.”

Works Cited

Davies, O. (2003). The Nightmare Experience, Sleep Paralysis, and Witchcraft Accusations. Folklore, 114(2), 181.

Fukuda, K. (2005). Emotions during sleep paralysis and dreaming. Sleep & Biological Rhythms, 3(3), 166-168. doi:10.1111/j.1479-8425.2005.00172.x

Girard, T. A., & Cheyne, J. (2006). Timing of spontaneous sleep-paralysis episodes. Journal Of Sleep Research, 15(2), 222-229. doi:10.1111/j.1365-2869.2006.00512.x

Nair, D., Kalra, G., DeSousa, A., & Shah, N. B. (2013). ISOLATED SLEEP PARALYSIS AND GENERALIZED ANXIETY DISORDER: A CASE REPORT AND REVIEW. ASEAN Journal of Psychiatry, 14(1)