Psychology

The current paper discusses the topic of sleep paralysis and its relation to human consciousness. A literature review is performed to evaluate the gaps in the current state of knowledge about sleep paralysis. Practical implications for studying this topic are discussed. The paper provides recommendations and proposes a future course of research with the topic of sleep paralysis.

Sleep Paralysis and Consciousness
Introduction and Literature Review

Recent developments in psychology and the study of human consciousness have been marked with the growing attention toward the topic of sleep paralysis. The current state of literature treats sleep paralysis as a product of multiple external and internal cognitive influences, but the specific nature of sleep paralysis is yet unknown. In its current state, professional literature on the topic links sleep paralysis to stress, sexual traumas, and cultural influences. These, actually, exemplify the three broad literature trends in the present state of knowledge about sleep paralysis.

Sleep paralysis is defined as a transient, conscious state of involuntary immobility occurring when falling asleep or upon wakening. It has been associated with sleep-onset rapid eye movement periods or mixed or incipient rapid eye moving and waking electroencephalogram in laboratory studies (Cheyne 2002, p. 169). Although definitions of sleep paralysis vary, it is usually referred to as the human inability to perform voluntary movements at sleep onset or during awakening (Sherwood, 2002). Sleep paralysis episodes are reported to last from a few seconds to a few minutes (Sherwood, 2002). The end of a sleep paralysis episode occurs either because of individual efforts to overcome it or under the influence of external disturbances (e.g., street noise) (Sherwood, 2002). The frequency of episodic sleep paralysis varies, but 40-50 of normal people are estimated to have experienced isolated sleep paralysis at least once in a lifetime (Sherwood, 2002). Very often, the incidence and prevalence of sleep paralysis in individuals are being linked to their cultural origin.

Several studies link sleep paralysis to ethnicity culture. According to Dahlitz and Parkes (1993), prevalence of isolated sleep paralysis varies among different ethnic groups, and can be as high as 62. Friedman and Paradis (2002) and Bell (2008) support these findings and confirm higher prevalence of sleep paralysis among blacks, compared with whites. These variations in prevalence among ethnic groups are not associated with the genetic predisposition of African-Americans to sleep disturbances rather, there is a whole set of reasons that may justify higher risks of sleep paralysis in African Americans. According to Friedman and Paradis (2008), these include higher levels of stress, disturbances in the sleep cycle, and even higher prevalence of hypertension in the African-American individuals. It should be noted, that stress is one of the definitive features of the current research about sleep paralysis, and researchers tend to believe that stress, panic disorders, and depression (even self-reported) can be the major sources of SP risks in different population groups.

Friedman and Paradis (2008) suggest that sleep paralysis is integrally linked to panic disorder and the feeling of distress in individuals. Solomonova et al (2006) add to this state of knowledge, by suggesting that sleep paralysis is associated with social anxiety and related psychiatric disorders, including bipolar disorder, depression, PTSD, anxiety disorder with agoraphobia, and generalized anxiety disorder. Sleep paralysis often goes in line with the sensed or felt presence experiences, which are closely associated with the distress-prone temperament in individuals (Nielsen, 2007). However, stress is not the only issue within the sleep paralysis paradigm sexual arousal, the feeling of sexual abuse, and the notion of sexual trauma represent another aspect of the sleep paralysis research.

Sexuality is a recurrent topic in the discussion of sleep paralysis. Reported sexual experiences during sleep paralysis range from sexual arousal to the fear of rape. Females report significantly more intense sexual experiences these are accompanied by higher levels of fear of rape, compared with men (Cheyne, 2002). Researchers explain these fears by cultural variations because traditional cultures often mention a form of demonic rape performed by supernatural creatures (Cheyne, 2002 Cheyne, Rueffer  Newby-Clark, 1999). Parker and Blackmore (2002) describe these experiences as false but sincere accusations of sexual abuse. McNally and Clancy (2005) go further, suggesting that sleep paralysis is the product of continuous memories of childhood sexual abuse, although in their analysis of Anna O.s black snake hallucination, Powell and Nielsen (1998) do not mention anything about sexual arousal or erotic experiences. The effects of these findings are two-fold on the one hand, they link sleep paralysis to erotic experiences and, on the other hand, imply that sleep paralysis can be the result of sexual trauma(s). These findings also link the topic of sleep paralysis to the study of psychology of consciousness.

The topic of sleep paralysis directly relates to the study of consciousness. Sleep paralysis is described as an altered state of consciousness (Friedman  Paradis, 2008). Researchers view sleep paralysis as less a disorder of REM than of transitions in states of consciousness (Cheyne, 2002). However, there is no certainty as for whether sleep paralysis is pathological abnormal, and this issue requires further detailed examination.

Discussion Summary Conclusion
The current state of knowledge about sleep paralysis is surrounded by controversy. Because sleep is fairly regarded as an important element of conscious activity in individuals and because sleep disorders impact the quality and effectiveness of conscious activity in people, sleep paralysis directly relates to the scientific study of psychology of consciousness. What professionals know about sleep paralysis is only the starting point in the subsequent analysis of factors and risks responsible for the development of SP experiences in different groups of individuals. The lack of standardized approaches to professional research, the lack of independent variables, the variability of cultural norms, and the difficulties with interpreting SP experiences by individuals are cited among the most serious research drawbacks. These issues and inconsistencies are, actually, responsible for the lack of a clear understanding of what sleep paralysis is, and what role human consciousness plays in the development of SP episodes.

The lack of independent measures is, probably, the primary factor responsible for the existing literature inconsistencies on the topic of sleep paralysis. Researchers intentionally or unintentionally limit the scope of their research to timing, frequency, and duration of SP experiences and seek to investigate the role of culture and stress. Sometimes, other factors like sleeping position become an object of peer analysis (Girard  Cheyne, 2006). However, factors other than timing and stress should be taken into account for example, Cheyne (2002) proposes that researchers evaluate the impact of atmospheric pressure on homeostatic mechanisms.

Researchers in the field of sleep paralysis rely on individual reports provided by research subjects. The contents of these reports can be doubtful or ambiguous. For example, Parker and Blackmore (2002) write that the exact physiological state of individuals, who experience SP, remains unknown. Thus, when individuals refer to their state as fully awake, there is still a possibility that they experience some form of false awakening, which they cannot describe in detail (Parker  Blackmore, 2002). Given the cultural variations in the discussion of sleep paralysis, there is a degree of ambiguity in how people describe their SP experiences. Different cultures may treat different experiences in completely different ways, and what is considered a negative product of sexual abuse in one culture can readily serve an acceptable element and a dream norm in another. There is some degree of uncertainty with regard to the availability and or lack of terminology necessary to describe SP experiences by people. Some of them may not have the level of education and language high enough to participate in such studies. As a result, the current state of knowledge about sleep paralysis is still far from being perfect, and there is still much room for research improvements.

In light of the recent research findings and the existing research controversies, future research should resolve the two essential issues. First, it is important that researchers finally define whether sleep paralysis represents a state of abnormalcy or whether it is a normal element of conscious activity in individuals. Objectively, the degree to which sleep paralysis is abnormal remains the topic of the hot professional debate. Sherwood (2002) associates sleep paralysis with anomalous experiences, including ESP, PK, NDES, and extraterrestrials, but whether sleep paralysis is anomalous by itself is yet unclear. In the same way, Parker and Blackmore (2002) suggest that SP experiences differ significantly from accepted dream norms, and SP sufferers display higher scores on various psychopathology tests. Simultaneously, psychopathology was not found to influence the frequency of SP occurrence (Parker  Blackmore, 2002). Because researchers view sleep paralysis as a form of the altered state of consciousness (Friedman  Paradis, 2008) and because sleep paralysis experiences are always associated with the sensed or felt presence attacks (Nielsen, 2007), SP is often believed to be a form of abnormalcy. However, according to Nielsen (2007), felt presence experiences can be present as a part of normal life experiences like bereavement, and can support individuals in the process of creating realistic social imagery. As a result, the abnormalcy status of sleep paralysis will predict and predetermine the quality and direction of future research in this field of psychology and consciousness.

The role, which sexual abuse and sexual experiences play in sleep paralysis, can serve another effective direction for future research. Recent research findings produce a controversial impression on the one hand, sleep paralysis experiences are often accompanied by sexual arousal and the fear of sexual abuse (Parker  Blackmore, 2002) on the other hand, sleep paralysis is sometimes described as a product of continuous sexual abuse experiences (McNally and Clancy, 2005). Taking into account the important role of sexual experiences in human consciousness, future research should concentrate on the study of the sexual element of SP. A good idea for the future study of sleep paralysis would be to investigate the risks of sleep paralysis in people with childhood sexual trauma experiences, and to identify how abnormal these SP paralysis experience can be, given the overall abnormalcy of sexual abuse during childhood.

All these directions and future findings will have practical implications for those, who seek to analyze sleep disorders in people and their relation to other psychopathologies and states of consciousness. It is important to understand, how abnormal sleep paralysis is and what changes it can produce in human consciousness. Future research will help professionals in psychology link human experiences (e.g., sexual trauma) to sleep paralysis and develop effective treatment methodology (if necessary). However, the need for such treatment remains obscure and confusing, until researchers are able to define the abnormalcy status of sleep paralysis. The findings that were discussed in this paper are too controversial to help professionals resolve the existing research and treatment controversies. However, the current state of literature can serve a good starting point in the subsequent analysis of the most controversial issues and findings on the topic of sleep paralysis.