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Something wicked this way comes: Causes and interpretations of sleep paralysis
Abstract
Sleep paralysis consists of a period of inability to perform voluntary movements at sleep onset or upon awakening, either during the night or in the morning. It is classified as an REM (rapid eye movement) sleep parasomnia; that is, an undesirable sleep disturbance that occurs during sleep that is characterised by the kind of rapid eye movements (REMs) typically associated with dreaming. During an episode of sleep paralysis, the individual is fully conscious and aware that it is not possible to move limbs, head and trunk, and there may also be respiratory difficulties. Sleep paralysis represents a unique altered state of consciousness, although there is still a lot to learn about this puzzling phenomenon.
... SP episodes appear to constitute a mixture of waking consciousness and two aspects of rapid eye movement (REM) sleep (i.e., muscle atonia and dream imagery). 1,20 However, some sufferers explain their symptoms as something supernatural or extraordinary, whether it be a result of aliens, spirits, or ghost visits. 20,21 In Egypt for example, SP is conceptualised as a "jinn attack"a supernatural creature that assaults, and in many cases murders its victims. ...
... 1,20 However, some sufferers explain their symptoms as something supernatural or extraordinary, whether it be a result of aliens, spirits, or ghost visits. 20,21 In Egypt for example, SP is conceptualised as a "jinn attack"a supernatural creature that assaults, and in many cases murders its victims. 22 Similarly, many people experiencing SP in China believe it is ghost oppression. ...
Study objectives:
Isolated sleep paralysis is a benign but frightening condition characterised by a temporary inability to move at sleep onset or upon awakening. Despite the prevalence of this condition, little is known concerning its clinical features, associated demographic characteristics, and prevention as well as disruption strategies.
Methods:
An online cross-sectional study was conducted. The sample comprised 3523 participants who had reported at least one lifetime episode of ISP and 3288 participants without a lifetime episode. Participants answered a survey including questions about sleep quality, sleep paralysis, and sleep paralysis prevention/disruption techniques.
Results:
A total of 6811 participants were investigated (mean age = 46.9, SD = 15.4, age range = 18-89, 66.1% female). Those who reported experiencing ISP at least once during their lives reported longer sleep onset latencies, shorter sleep duration, and greater insomnia symptoms. Females (vs. male) and younger (vs. older) participants were more likely to experience ISP. Significant fear during episodes was reported by 76.0% of the participants. Most people (63.3%) who experienced ISP believed it to be caused by 'something in the brain'. A minority endorsed supernatural causes (7.1%). Five prevention strategies (e.g., changing sleep position, adjusting sleep patterns) with at least 60.0% effectiveness, and five disruption strategies (e.g., physical/bodily action, making noise) with varying degrees of effectiveness (ranging from 29.5 to 61.8) were identified through open-ended responses.
Conclusions:
ISP is associated with shorter sleep duration, longer sleep onset latency, and greater insomnia symptoms. The multiple prevention and disruption techniques identified in this study support existing treatment approaches and may inform subsequent treatment development. Implications for current diagnostic criteria are discussed.
... Understandably, these sensations and hallucinations can be frightening and distressing (42). Because sleep paralysis is not well known, many people lack a scientific explanation for their experience and attribute it to a paranormal entity such as a demon, ghost, or extraterrestrial (43,44). Individuals reporting abduction by extraterrestrials are more likely to experience sleep paralysis than those who do not report abduction (5). ...
A biopsychosocial model provides a framework for a contemporary understanding of paranormal phenomena. From this perspective, paranormal beliefs and experiences are best understood by identifying biological, psychological, and sociocultural explanatory factors. Treatment recommendations are provided.
... In many places, sleep paralysis experiences are interwoven with a culture's folklore [4,5]. Episodes of sleep paralysis have been suggested as an explanation for supposed paranormal phenomena such as witchcraft [6], demonic assault [7], and space alien abduction [8,9]. Fear and distress are typically associated with episodes [2], though feelings of bliss are sometimes reported [10]. ...
Sleep paralysis is a relatively common but under-researched phenomenon. While the causes are unknown, a number of studies have investigated potential risk factors. In this article, we conducted a systematic review on the available literature regarding variables associated with both the frequency and intensity of sleep paralysis episodes. A total of 42 studies met the inclusion criteria. For each study, sample size, study site, sex and age of participants, sleep paralysis measure, and results of analyses looking at the relationship(s) between sleep paralysis and associated variable(s) were extracted. A large number of variables were associated with sleep paralysis and a number of themes emerged. These were: substance use, stress and trauma, genetic influences, physical illness, personality, intelligence, anomalous beliefs, sleep problems and disorders (both in terms of subjective sleep quality and objective sleep disruption), symptoms of psychiatric illness in non-clinical samples (particularly anxiety symptoms), and psychiatric disorders. Sleep paralysis appears to be particularly prevalent in post-traumatic stress disorder, and to a less degree, panic disorder. Limitations of the current literature, directions for future research, and implications for clinical practice are discussed.
... Researchers have also associated sleep paral- ysis experiences and sleep deprivation with spiritual and mystical experiences (Hufford, 2005;Pahnke, 1966). Hypnopompic (the tran- sition between sleep and wakefulness) and hyp- nagogic (the transition between wakefulness and sleep) phenomena, which may include com- plex visual, auditory, and somatosensory expe- riences, have been related to creative thinking and ostensible psi phenomena (Mavromatis, 1987), as well as to the experience of seeing the deceased and vivid, frightening hallucinations of malevolent spirits attempting to attack or contact the sleeping person (French & Santomauro, 2007 ...
This essay presents the rationale to consider anomalous experiences (AEs, such as synesthesia, lucid dreaming, hallucinations, psi-related experiences, and near-death experiences) as an essential topic in psychology. These experiences depart from the typical or customary characteristics of consciousness (e.g., out-of-body experiences), or from ordinary or normative consciousness (e.g., synesthesia), and sometimes offer an alternative perspective to the nature of self and reality. We review the concept of AEs, methodological issues, and research findings, including their relation to individual differences, psychopathology, culture, and positive psychology. We suggest that mainstream psychology has neglected the study of AEs far too long, although they often engender profound and sometimes highly positive personal and social consequences, and provide valuable insights into the full range of human experience. We propose that the time is ripe to advance the scientific interest in AEs and subject them to rigorous empirical examination in studies that explore their prevalence, phenomenology, and sequelae, and take into account the direct and interactive effects of multiple variables (e.g., genetic predisposition, psychophysiology, personality differences, sociocultural factors). This will extend the purview of inquiry and understanding of our uniquely human nature and potential.
... Perhaps not surprisingly, SP has been thought to have a role in the genesis and/or maintenance of many supernatural beliefs (eg, nocturnal alien abductions and demonic attacks) in individuals with otherwise intact reality testing. 2,3 Though noted by physicians and other scholars since the ancient Greeks, SP only recently began receiving attention from nonsleep specialists. This was partly due to the publication of books aimed at a broader readership, 4 popular films on SP, 5,6 and attention from the popular press. ...
This review summarizes the empirical and clinical literature on sleep paralysis most relevant to practitioners. During episodes of sleep paralysis, the sufferer awakens to rapid eye movement sleep-based atonia combined with conscious awareness. This is usually a frightening event often accompanied by vivid, waking dreams (i.e., hallucinations). When sleep paralysis occurs independently of narcolepsy and other medical conditions, it is termed “isolated” sleep paralysis. Although the more specific diagnostic syndrome of “recurrent isolated sleep paralysis” is a recognized sleep–wake disorder, it is not widely known to nonsleep specialists. This is likely due to the unusual nature of the condition, patient reluctance to disclose episodes for fear of embarrassment, and a lack of training during medical residencies and graduate education. In fact, a growing literature base has accrued on the prevalence, risk factors, and clinical impact of this condition, and a number of assessment instruments are currently available in both self-report and interview formats. After discussing these and providing suggestions for accurate diagnosis, differential diagnosis, and patient selection, the available treatment options are discussed. These consist of both pharmacological and psychotherapeutic interventions which, although promising, require more empirical support and larger, well-controlled trials.
... During REM sleep, the amygdala—like other parts of the brain—is in a heightened state of alertness, which may cause the person to perceive ambiguous aspects of the environment as threatening (LeDoux, 1998, as cited in French & Santomauro, 2007). During sleep paralysis, people sometimes sense a presence (i.e., have the feeling that a being of some kind was present). ...
Sleep paralysis is the inability to move upon falling asleep or awakening; in the present study, it was found to affect 40.7% of the sample. The few studies that examined the relationship between sleep paralysis and personality, found only a relationship between the experience and Neuroticism. Earlier studies found that sleep paralysis may be associated with individual differences including sex, age, depression and anxiety levels, and sleep irregularities. The present study examined the relationships between sleep paralysis and sleep habits, demographics, and personality factors. The results showed that people who experience sleep paralysis tend to sleep less and score higher for Openness to Experience.
... Occasionally, however, people are conscious during this phase and, in addition to an awareness that they are unable to move, they may experience a puzzling (and sometimes frightening) variety of auditory (e.g., heavy footsteps, buzzing) and visual experiences (lights, strange figures; Holden & French, 2002). As Lynn and Kirsch (1996) suggest, someone who is predisposed to accept such puzzling experiences as telltale signs of UFO abduction (perhaps due to widely available UFO abductions scripts that are common in our culture; Clancy, 2005) may well seek out a therapist who is receptive to such ideas who then reinforces this belief and encourages the individual to try and remember more about the event(s) (French & Santomauro, 2007). Given that the dominant abduction script often (but not always; see Spence, 1996) consists of some kind of sexual experimentation, this may explain why such individuals come to report that they remember experiences like having sperm and eggs removed. ...
KEY POINTS DIFFERENT TYPES OF ‘RECOVERED MEMORY’ EXPERIENCE FALSE BELIEFS VERSUS FALSE MEMORIES FALSE BELIEFS AND MEMORIES IN THE WILD FALSE BELIEFS AND MEMORIES IN THE LABORATORY HOW LONG DO LABORATORY-GENERATED FALSE BELIEFS AND MEMORIES LAST? THE CONSEQUENCES OF FALSE BELIEFS AND MEMORIES THE PERSISTENCE OF FALSE BELIEFS AND FALSE MEMORIES WHERE NEXT? CONCLUSIONS AND FORENSIC IMPLICATIONS REFERENCES
... Sleep paralysis involves a period of inability to perform voluntary movements at either sleep onset or upon awakening (International Classification of Sleep Disorders, Third Edition, American Academy of Sleep Medicine, 2014). Sleep paralysis is often accompanied by a wide range of terrifying hallucinations (French and Santomauro, 2007). One systematic review suggested that 7.6% of individuals experienced sleep paralysis at least once in their lives, although individual estimates range widely between 2 and 60% (Sharpless and Barber, 2011). ...
Sleep paralysis is a relatively common but under-researched phenomenon. In this paper we examine prevalence in a UK sample and associations with candidate risk factors. This is the first study to investigate the heritability of sleep paralysis in a twin sample and to explore genetic associations between sleep paralysis and a number of circadian expressed single nucleotide polymorphisms. Analyses are based on data from the Genesis1219 twin/sibling study, a community sample of twins/siblings from England and Wales. In total, data from 862 participants aged 22–32 years (34% male) were used in the study. This sample consisted of monozygotic and dizygotic twins and siblings. It was found that self-reports of general sleep quality, anxiety symptoms and exposure to threatening events were all associated independently with sleep paralysis. There was moderate genetic influence on sleep paralysis (53%). Polymorphisms in the PER2 gene were associated with sleep paralysis in additive and dominant models of inheritance— although significance was not reached once a Bonferroni correction was applied. It is concluded that factors associated with disrupted sleep cycles appear to be associated with sleep paralysis. In this sample of young adults, sleep paralysis was moderately heritable. Future work should examine specific polymorphisms associated with differences in circadian rhythms and sleep homeostasis further in association with sleep paralysis.
... SP is widely reported in the general population (Arikawa et al., 1999;Awadalla et al., 2004;Cheyne et al., 1999aCheyne et al., ,1999bFukuda et al., 1998;Kotorii et al., 2001;Ohayon et al., 1999;Spanos et al., 1995) and is frequently accompanied by diverse and often vivid hallucinations (e.g., Hishikawa, 1976;Hufford, 1982). SP-related hallucinations are likely important contributors to a variety of paranormal beliefs and supernatural traditions (Hufford, 1982;French and Santomauro, 2007). ...
Sleep paralysis is a transient, conscious state of involuntary immobility occurring immediately prior to falling asleep or upon wakening and is classified as a parasomnia associated with REM (Thorpy, 1990). Although individuals are unable to make gross bodily movements during sleep paralysis many are able to open their eyes and subsequently to report events that occurred during the episode. An acute sense of fear and frightening hypnagogic (predormital) and hypnopompic (postdormital) experiences often accompany sleep paralysis.
... People can often come to believe that their house or workplace is haunted following an initial unusual experience that seems to them only to be explicable in paranormal terms. That initial event may be psychological in nature (e.g., a frightening episode of sleep paralysis; see French and Santomauro, 2007) or some physical event that defies any obvious explanation (e.g., an item of furniture that appears to have moved when the house was locked and empty). Tandy and Lawrence (1998: p. 360) suggest a number of obscure non-paranormal causes of ostensible ghostly activity including ''water hammer in pipes and radiators (noises), electrical faults (fires, phone calls, video problems), structural faults (draughts, cold spots, damp spots, noises), seismic activity (object movement/destruction, noises) [.] and exotic organic phenomena (rats scratching, beetles ticking)''. ...
Recent research has suggested that a number of environmental factors may be associated with a tendency for susceptible individuals to report mildly anomalous sensations typically associated with "haunted" locations, including a sense of presence, feeling dizzy, inexplicable smells, and so on. Factors that may be associated with such sensations include fluctuations in the electromagnetic field (EMF) and the presence of infrasound. A review of such work is presented, followed by the results of the "Haunt" project in which an attempt was made to construct an artificial "haunted" room by systematically varying such environmental factors. Participants (N=79) were required to spend 50 min in a specially constructed chamber, within which they were exposed to infrasound, complex EMFs, both or neither. They were informed in advance that during this period they might experience anomalous sensations and asked to record on a floor plan their location at the time of occurrence of any such sensations, along with a note of the time of occurrence and a brief description of the sensation. Upon completing the session in the experimental chamber, they were asked to complete three questionnaires. The first was an EXIT scale asking respondents to indicate whether or not they had experienced particular anomalous sensations. The second was the Australian Sheep-Goat Scale, a widely used measure of belief in and experience of the paranormal. The third was Persinger's Personal Philosophy Inventory, although only the items that constitute the Temporal Lobe Signs (TLS) Inventory sub-scale were scored. These items deal with psychological experiences typically associated with temporal lobe epilepsy but normally distributed throughout the general population. Although many participants reported anomalous sensations of various kinds, the number reported was unrelated to experimental condition but was related to TLS scores. The most parsimonious explanation for our findings is in terms of suggestibility.
... Many commentators believe that the experience of sleep paralysis is one of the triggers that lead some people to develop the belief that they have been abducted by aliens (e.g., Holden and French, 2002;McNally and Clancy, 2005). Sleep paralysis is a common but frightening experience that takes place in the state between sleep and wakefulness (French and Santomauro, 2007). During sleep paralysis, sufferers become aware of the fact that they cannot move and the general cognitive state of the sufferer appears to be a blend of normal waking consciousness and dream mentation. ...
Previous research has shown that people reporting contact with aliens, known as "experiencers", appear to have a different psychological profile compared to control participants. They show higher levels of dissociativity, absorption, paranormal belief and experience, and possibly fantasy proneness. They also appear to show greater susceptibility to false memories as assessed using the Deese/Roediger-McDermott technique. The present study reports an attempt to replicate these previous findings as well as assessing tendency to hallucinate and self-reported incidence of sleep paralysis in a sample of 19 UK-based experiencers and a control sample matched on age and gender. Experiencers were found to show higher levels of dissociativity, absorption, paranormal belief, paranormal experience, self-reported psychic ability, fantasy proneness, tendency to hallucinate, and self-reported incidence of sleep paralysis. No significant differences were found between the groups in terms of susceptibility to false memories. Implications of the results are discussed and suggestions are made for future avenues of research.
... SP is widely reported in the general population (Arikawa et al., 1999; Awadalla et al., 2004; Cheyne et al., 1999a Cheyne et al., ,1999b Fukuda et al., 1998; Kotorii et al., 2001; Ohayon et al., 1999; Spanos et al., 1995) and is frequently accompanied by diverse and often vivid hallucinations (e.g., Hishikawa, 1976; Hufford, 1982 ). SP-related hallucinations are likely important contributors to a variety of paranormal beliefs and supernatural traditions (Hufford, 1982; French and Santomauro, 2007 ). In a series of studies, we have found that SP-related experiences can be reliably sorted into three factors (Cheyne, 2003Cheyne, , 2005 Cheyne et al., 1999b; Girard, 2004, 2007a). ...
Among the varied hallucinations associated with sleep paralysis (SP), out-of-body experiences (OBEs) and vestibular-motor (V-M) sensations represent a distinct factor. Recent studies of direct stimulation of vestibular cortex report a virtually identical set of bodily-self hallucinations. Both programs of research agree on numerous details of OBEs and V-M experiences and suggest similar hypotheses concerning their association. In the present study, self-report data from two on-line surveys of SP-related experiences were employed to assess hypotheses concerning the causal structure of relations among V-M experiences and OBEs during SP episodes. The results complement neurophysiological evidence and are consistent with the hypothesis that OBEs represent a breakdown in the normal binding of bodily-self sensations and suggest that out-of-body feelings (OBFs) are consequences of anomalous V-M experiences and precursors to a particular form of autoscopic experience, out-of-body autoscopy (OBA). An additional finding was that vestibular and motor experiences make relatively independent contributions to OBE variance. Although OBEs are superficially consistent with universal dualistic and supernatural intuitions about the nature of the soul and its relation to the body, recent research increasingly offers plausible alternative naturalistic explanations of the relevant phenomenology.
Sleep paralysis is a period of time at sleep onset or upon awakening from sleep during which voluntary muscle movements are inhibited. Ocular and respiratory movements remain unaltered and perception of the immediate environment is clear. A common symptom of narcolepsy, the term isolated sleep paralysis is preferred when sleep paralysis is present in the absence of a narcolepsy diagnosis. The presence of frequent episodes is termed recurrent isolated sleep paralysis. Alongside the paralysis, episodes are accompanied by a range of bizarre and often terrifying hallucinations.
This brief clinical review summarizes the literature on sleep paralysis most relevant to clinicians. Sleep paralysis is a condition where the sufferer awakens to rapid eye movement sleep based atonia, combined with conscious awareness. This is a frightening event accompanied by vivid, waking dreams and hallucinations. Sleep paralysis occurring independent of narcolepsy and other medical conditions is termed isolated sleep paralysis. Though rare in clinical practice, the unusual nature of the condition and a lack of training during medical residency and graduate education leads to fewer cases being detected. This paper looks at the prevalence, risk factors, diagnosis and management of sleep paralysis. The management consists of both pharmacological and psychotherapeutic interventions that need clear guidelines, empirical support and larger randomized controlled trials.
Sleep paralysis is a state of sleep disturbance in which people experience hypnogogic or hypnopompic hallucinations marked by an inability to move their bodies or speak out while reporting the consciousness about their surroundings. Philosophical explanation of sleep paralysis has been quoted in the ancient texts in terms of incubus and succubus. However, pathologically, it has been linked to several disorders including narcolepsy, migraines, anxiety disorders, and obstructive sleep apnea but it can also occur in isolation. Some other significant factors may include perceived stress, spiritual and paranormal beliefs, etc. Hence, a qualitative analysis of five such cases reporting symptoms of sleep disturbances with the criterion of sleep paralysis has been reported here. The study considered various psychological factors like stressful life events, feelings of inadequacy, spirituality, and paranormal beliefs. Results disclosed that four of the five cases were inclined towards the paranormal beliefs and the entire sample indicated a noticeably augmented level of spirituality and feelings of inadequacy. Furthermore, three cases reported experiencing greater stress following life events. Among other factors, all the cases were characterized with sleeping in the supine position, sleeping alone, an experience of fear, a sense of pressure on their chest, a presence of someone in the room and increased level of feelings of inadequacy.
Keywords: Genesis, Inadequacy, Paranormal, Sleep-Paralysis, Spiritual, Stress
A large proportion of the general population believes that dreams can provide information about future events that could not have been obtained by any known means. The present study identifies several factors associated with prophetic (precognitive) dream belief and experience. Participants (. N=. 672) were measured on demographic variables, sleep characteristics, and precognitive dream (PD) belief, experience, and frequency. Three 'sleep clusters' were identified based on the analysis of the sleep-related variables. Women were more likely to believe in PDs as well as experience them. There was a positive relationship of PD belief and experience with age and a negative one with education. Most notably, we found that a high frequency of PD experiences was associated with erratic sleep patterns and sleep medication use. The present study provides a basis for the development of further models explaining the prevalent phenomena of precognitive dream belief and experience.
Sleep paralysis can be a terrifying experience that is suprisingly common. It can involve the inability to move, auditory and visual hallucinations, a strong sense of presence, difficulty breathing, sensations of movement, and intense emotion. The causes and interpretations of sleep paralysis are described in this article, as well as some practical suggestions for coping with it.
Isolated sleep paralysis (ISP) is a poorly understood phenomenon that has attracted increased attention in recent years both in the medical community (Dahlitz & Parkes, 1993; Hishikawa & Shimizu, 1995) and in psychological research (Fukuda et al., 1987, 1991; Fukuda, 1993; Takeuchi et al., 1994; Wing et al., 1994). Although the occurrence of ISP is relatively common, recurrent ISP (RISP) is a rarer variant of sleep paralysis characterized by frequent episodes or a complex of sequential episodes whose total duration may exceed 1 hour, and particularly by the range and sense of perceived reality of the subjective phenomena experienced during episodes. Although such phenomena are usually categorized as hypnagogic or hypnopompic hallucinations, there is at present no integrated model that adequately explains the ensemble of physiological, neurological, cognitive, and psychological components of RISP. As researchers who experience RISP, in this paper we attempt to synthesize information on RISP gathered from various sources and to conjecture possible connections between RISP and other as yet poorly understood phenomena at different levels: at a neurophysiological level, with anxiety disorders (Suarez, 1991; Paradis et al., 1997), the Periodic Paralyses (Stedwell et al., 1992), and with Sudden Unexplained Nocturnal Death Syndrome (SUNDS) (Nimmanit et al., 1991; Randall, 1992; Adler, 1995); at a neurocognitive level, with lucid dreaming (LaBerge, 1985); and finally, at a level that examines the possibility of the manifestation of paranormal phenomena during RISP episodes, with Out-of-Body Experiences (OBE) (Tart, 1968; Osis, 1981) and with Near-Death-Experiences (NDE) (Moody, 1976; Ring, 1979). Finally, we performed a statistical analysis on RISP by use of a sample of 250 direct or indirect respondents to a message posted initially by one of the authors on the sleep web site of the University of California in Los Angeles (UCLA). Preliminary results indicate that over 90% of respondents experience intense fear during their RISP episodes, about 50% have invoked a paranormal or supernatural explanation, and that a typical RISP episode may be described as consisting of three main phases. We conclude with a brief description of possible strategies to cope with RISP.
Sleep paralysis is an essentially rare condition of unknown aetiology associated with both the narcolepsy-cataplexy syndrome and with psychological dissociative experiences. This supposedly rare condition seems to be well known to Alaska Eskimos, having Eskimo names, a traditional cause, and a method for treatment. Pertinent literature is reviewed on sleep paralysis, Eskimo personality dynamics, in particular the use of hysterical mechanisms, and traditional explanations for phenomena of this type including literature on shamanism. Suggestions are made for the clinical approach to patients in the cross-cultural setting.
The articles in this special issue of the journal "Transcultural Psychiatry," examine cultural variations in sleep paralysis, a phenomenon that is both little known and remarkably common. Sleep paralysis must be distinguished from nightmares, nocturnal panic, and night terrors. In some cases, a person may awake in terror but have no memory of a dream; this may represent nocturnal panic, a phenomenon that has been found in 18-45% of patients with panic disorder. In night terrors, the person seems to awaken in fear and agitation, flailing about and talking loudly, but then falls back asleep and is amnesic for the event in the morning. Each of these types of event has been confused with sleep paralysis. In sleep paralysis, the person, during sleep onset or awakening, finds themselves completely awake but unable to move their limbs or speak. Often, the person sees a form, which may be shadow-like or indistinct, move toward him or her; frequently, the experience is also associated with an oppressive feeling of chest tightness, weight on the chest or body, or a sensation of shortness of breath. The paralysis may last from seconds to minutes. Sleep paralysis is understood as a disturbance of the normal regulation of sleep in which the muscular paralysis characteristic of REM sleep occurs during a state of waking arousal. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Isolated sleep paralysis (ISP) is a poorly understood phenomenon that has attracted increased attention in recent years both in the medical com-munity (Dahlitz & Parkes,. Although the occurrence of ISP is relatively common, recurrent ISP (RISP) is a rarer variant of sleep paralysis character-ized by frequent episodes or a complex of sequential episodes whose total du-ration may exceed 1 hour, and particularly by the range and sense of per-ceived reality of the subjective phenomena experienced during episodes. Although such phenomena are usually categorized as hypnagogic or hypnopompic hallucinations, there is at present no integrated model that ade-quately explains the ensemble of physiological, neurological, cognitive, and psychological components of RISP. As researchers who experience RISP, in this paper we attempt to synthesize information on RISP gathered from vari-ous sources and to conjecture possible connections between RISP and other as yet poorly understood phenomena at different levels: at a neurophysiolog-ical level, with anxiety disorders (Suarez, at a neurocognitive level, with lucid dreaming (LaBerge, 1985); and finally, at a level that examines the possibility of the manifesta-tion of paranormal phenomena during RISP episodes, with Out-of-Body Ex-periences (OBE) (Tart,1968; Osis, 1981) and with Near-Death-Experiences (NDE) (Moody, 1976; Ring, 1979). Finally, we performed a statistical analy-sis on RISP by use of a sample of 250 direct or indirect respondents to a mes-sage posted initially by one of the authors on the sleep web site of the Uni-versity of California in Los Angeles (UCLA). 1 Preliminary results indicate that over 90% of respondents experience intense fear during their RISP episodes, about 50% have invoked a paranormal or supernatural explanation, and that a typical RISP episode may be described as consisting of three main phases. We conclude with a brief description of possible strategies to cope with RISP.
Sleep paralysis is a clinical phenomenon that is often a feature of narcolepsy. As its co-existence with panic disorder has not been noted before, we report on two cases in which the two conditions co-exist and postulate a neurochemical mechanism.
We elicited isolated sleep paralysis (ISP) from normal subjects by a nocturnal sleep interruption schedule. On four experimental nights, 16 subjects had their sleep interrupted for 60 minutes by forced awakening at the time when 40 minutes of nonrapid eye movement (NREM) sleep had elapsed from the termination of rapid eye movement (REM) sleep in the first or third sleep cycle. This schedule produced a sleep onset REM period (SOREMP) after the interruption at a high rate of 71.9%. We succeeded in eliciting six episodes of ISP in the sleep interruptions performed (9.4%). All episodes of ISP except one occurred from SOREMP, indicating a close correlation between ISP and SOREMP. We recorded verbal reports about ISP experiences and recorded the polysomnogram (PSG) during ISP. All of the subjects with ISP experienced inability to move and were simultaneously aware of lying in the laboratory. All but one reported auditory/visual hallucinations and unpleasant emotions. PSG recordings during ISP were characterized by a REM/W stage dissociated state, i.e. abundant alpha electroencephalographs and persistence of muscle atonia shown by the tonic electromyogram. Judging from the PSG recordings, ISP differs from other dissociated states such as lucid dreaming, nocturnal panic attacks and REM sleep behavior disorders. We compare some of the sleep variables between ISP and non-ISP nights. We also discuss the similarities and differences between ISP and sleep paralysis in narcolepsy.
An hypothesis is proposed that there exists a subgroup of African-American hypertensive patients whose hypertension could have been prevented by the early detection and treatment of easily recognizable symptoms that signal the initiation of the pathophysiologic processes that lead to essential hypertension.A pilot study of 31 patients with elevated blood pressure revealed that 41.9 percent had isolated sleep paralysis, 35.5 percent had panic attacks, and 9.7 percent had panic disorder. These proposed hyperadrenergic phenomena may be related to the development of hypertension in certain individuals.
In Japan, a set of experiences called kanashibari is considered identical with isolated sleep paralysis. We investigated this phenomenon by means of a questionnaire administered to 635 college students (390 men and 245 women). Of all subjects, about 40% had experienced at least one episode of kanashibari [subjects of K(+)]. Therefore, isolated sleep paralysis is apparently a more common phenomenon than is usually appreciated. About half of the subjects of K(+) reported that they had been under "physical or psychological stress" or in a "disturbed sleep and wakefulness cycle" immediately before the episode. Many subjects of K(+) experienced the first episode in adolescence. In the distribution of age of first attack, the peak occurred at an earlier age in women subjects than in men subjects. These findings suggest that two factors influence the occurrence of the phenomenon. One is exogenous physical or psychological load and the other is endogenous biological development.
Scores of seemingly healthy Hmong immigrants have died mysteriously and without warning from what has come to be known as Sudden Unexpected Nocturnal Death Syndrome (SUNDS). To date medical research has provided no adequate explanation for these sudden deaths. This study is an investigation into the role of powerful traditional beliefs in illness causation. In Stockton, California, 118 Hmong men and women were interviewed regarding their awareness of and personal experience with a traditional nocturnal spirit encounter. An analysis of this data reveals that the supranormal encounter acts as a trigger for Hmong SUNDS.
In a previous study, the author and coworkers found 39.8% of healthy young adults had experienced sleep paralysis. Some other studies reported prevalence as about the same or higher (i.e., 40.7% to 62.0%) than that previous estimate, while yet other studies, including Goode's work cited by ASDC and ASDA classifications, suggested much lower prevalences (i.e., 4.7% to 26.2%). The author tested the hypothesis that this discrepancy among the reported prevalences is partly due to the expression used in each questionnaire. University students who answered the questionnaire using the term 'transient paralysis' reported the lower prevalence (26.4%), while the second group of respondents who answered the questionnaire using the term kanashibari, the Japanese folklore expression for sleep paralysis, gave the higher prevalence (39.3%). The third group who answered the questionnaire with the term 'condition,' probably a rather neutral expression, marked the middle (31.0%) of these.
Hypnagogic and hypnopompic hallucinations are common in narcolepsy. However, the prevalence of these phenomena in the general population is uncertain.
A representative community sample of 4972 people in the UK, aged 15-100, was interviewed by telephone (79.6% of those contacted). Interviews were performed by lay interviewers using a computerised system that guided the interviewer through the interview process.
Thirty-seven per cent of the sample reported experiencing hypnagogic hallucinations and 12.5% reported hypnopompic hallucinations. Both types of hallucinations were significantly more common among subjects with symptoms of insomnia, excessive daytime sleepiness or mental disorders. According to this study, the prevalence of narcolepsy in the UK is 0.04%.
Hypnagogic and hypnopompic hallucinations were much more common than expected, with a prevalence that far exceeds that which can be explained by the association with narcolepsy. Hypnopompic hallucinations may be a better indicator of narcolepsy than hypnagogic hallucinations in subjects reporting excessive daytime sleepiness.
Isolated sleep paralysis (ISP) was assessed in African Americans and Whites diagnosed with panic disorder and other anxiety disorders. Participants were recruited from an outpatient clinic where they were diagnosed with panic disorder, generalized anxiety disorder, obsessive-compulsive disorder, social phobia, and simple phobia. Control groups of volunteers without a history of psychiatric disorder were included. All research participants completed a questionnaire to assess for ISP. Group differences were analysed through a series of chi-square analyses. The incidence of recurrent ISP was significantly higher in African Americans with panic disorder (59.6%) as compared with African Americans with other anxiety disorders (11.1%), African American control group participants (23%), Whites with panic disorder (7.5%), Whites with other anxiety disorders (0%), and White control group participants (6%). Recurrent ISP was found to be more common among African American participants, particularly for those with panic disorder. African Americans with panic disorder may experience recurrent ISP as a feature of their disorder.
To investigate the prevalence and illness beliefs of sleep paralysis (SP) among Chinese patients in a psychiatric out-patient clinic, consecutive Chinese/Chinese-American patients who attended psychiatric out-patient clinics in Boston and Shanghai were asked about their lifetime prevalence, personal experience and perceptions regarding the causes, precipitating factors, consequences, and help-seeking of SP. During the 4-month study period, 42 non-psychotic psychiatric out-patients from the Boston site and 150 patients from the Shanghai site were interviewed. The prevalence of SP was found to be 26.2% in Boston and 23.3% in Shanghai. Patients with post-traumatic stress disorder (PTSD) or panic disorder reported a higher prevalence of SP than did patients without these disorders. Patients attributed SP to fatigue, stress, and other psychosocial factors. Although the experience has traditionally been labeled 'ghost oppression' among the Chinese, only two patients, one from each site, endorsed supernatural causes of their SP. Sleep paralysis is common among Chinese psychiatric out-patients. The endorsement of supernatural explanations for SP is rare among contemporary Chinese patients.
Studies have reported a wide range in lifetime prevalence of sleep paralysis (SP). This variation may stem from cultural factors, stressful life events and genetic differences in studied populations. We found that recurrent SP was more common among African-American participants, especially those with panic disorder. Recurrent SP was reported by 59% of African Americans with panic disorder, 7% of whites with panic disorder, 23% of African-American community volunteers and 6% of white community volunteers. Significantly more early life stressors were reported by African Americans than whites. Higher levels of psychosocial stressors, including poverty, racism and acculturation, may contribute to the higher rates of SP experienced by African Americans.
Traditional and contemporary Inuit concepts of sleep paralysis were investigated through interviews with elders and young people in Iqaluit, Baffin Island. Sleep paralysis was readily recognized by most respondents and termed uqumangirniq (in the Baffin region) or aqtuqsinniq (Kivalliq region). Traditional interpretations of uqumangirniq referred to a shamanistic cosmology in which the individual's soul was vulnerable during sleep and dreaming. Sleep paralysis could result from attack by shamans or malevolent spirits. Understanding the experience as a manifestation of supernatural power, beyond one's control, served to reinforce the experiential reality and presence of the spirit world. For contemporary youth, sleep paralysis was interpreted in terms of multiple frameworks that incorporated personal, medical, mystical, traditional/shamanistic, and Christian views, reflecting the dynamic social changes taking place in this region.
ALTHOUGH the pathogenesis and pathophysiology of idiopathic narcolepsy remain obscure, it is known that symptomatic forms may follow head injury, cerebral arteriosclerosis, encephalitis lethargica, and intracranial tumors involving the posterior portion of the hypothalamus. Ranson¹ in 1939 produced somnolence in monkeys with lesions limited to the subthalamus and hypothalamus. It remained, however, for the recent studies of Magoun and his co-workers² clearly to show that afferent stimulation of the ascending activating system of the brain stem underlies wakefulness, while absence of this influence results in sleep. An arousal reaction, or state of wakefulness, was produced by stimulation of the dorsal portion of the hypothalamus, the subthalamus, the related medial bulbar reticular formation, or the tegmentum of the pons and midbrain. Lesions of the ventral portion of the diencephalon and the tegmentum of the midbrain, within the area of distribution of the ascending reticular activating system, produced recurrent electroencephalographic
Witch-trial records, and other early-modern writings on witchcraft, reveal that in various European societies people complained of being physically oppressed at night by witches and other supernatural beings, the victims of these nocturnal assaults describing a similar set of symptoms. Contemporary English authors termed the experience the "mare" or "nightmare." In the twentieth century, it has been identified as a manifestation of "sleep paralysis." Medical studies and surveys of the condition help us make better sense of the historical accounts, while an awareness of the historical evidence illuminates modern reports of sleep paralysis experiences. [1]
Reports of anomalous experiences are to be found in all known societies, both historically and geographically. If these reports were accurate, they would constitute powerful evidence for the existence of paranormal forces. However, research into the fallibility of human memory suggests that we should be cautious in accepting such reports at face value. Experimental research has shown that eyewitness testimony is unreliable, including eyewitness testimony for anomalous events. The present paper also reviews recent research into susceptibility to false memories and considers the relevance of such work for assessing reports of anomalous events. It is noted that a number of psychological variables that have been shown to correlate with susceptibility to false memories (e.g., hypnotic susceptibility, tendency to dissociate) also correlate with the tendency to report paranormal and related anomalous experiences. Although attempts to show a direct link between tendency to report anomalous experiences and susceptibility to false memories have had only limited success to date, this may reflect the use of inappropriate measures.
A 'sensed presence' often accompanies hypnagogic and hypnopompic hallucinations associated with sleep paralysis. Qualitative descriptions of the sensed presence during sleep paralysis are consistent with the experience of a monitoring, stalking predator. It is argued that the sensed presence during sleep paralysis arises because of REM-related endogenous activation of a hypervigilant and biased attentive state, the normal function of which is to resolve ambiguities inherent in biologically relevant threat cues. Given the lack of disambiguating environmental cues, however, the feeling of presence persists as a protracted experience that is both numinous and ominous. This experience, in turn, shapes the elaboration and integration of the concurrent hallucinations that often take on supernatural and daemonic qualities. The sense of presence considered here is an 'other' that is radically different from, and hence more than a mere projection of, the self. Such a numinous sense of otherness may constitute a primordial core consciousness of the animate and sentient in the world around us.
Isolated sleep paralysis (SP) is a common sleep phenomenon that is highly colored by indigenous beliefs. In Hong Kong Chinese, the ‘ghost oppression phenomenon’ (GO) has been shown to be descriptively identical to SP. The prevailing concept is that the majority of cases with SP have their onset during adolescence, but the lack of any systematic study on an older population means that late-onset cases can not be excluded. In a study investigating the prevalence of mental disorders in Chinese elderly aged above 70 y in Hong Kong, we employed the revised GO questionnaire to study the prevalence of SP in this group of elderly as well. One hundred and fifty-eight subjects were finally analyzed for the study. Almost 18% (95% C.I. 11.77%, 23.68%) of the subjects reported experiences of GO. Their description of the features of GO showed striking similarity to those of SP. There was a clear bimodal distribution of onset of GO with peaks during adolescence and after age 60 y. At least one-third of the cases were late onset. In concordance with the rapid eye movement (REM)/wakefulness dissociation hypothesis of SP, those elderly with GO+ experiences also had more frequent nocturnal sleep disturbances. A family history was reported in 10% of subjects.
In a sample of 1798 university undergraduates (females, n = 976; males, n = 822) 21% reported one or more episodes of sleep paralysis, and there was no significant sex difference in this regard. Most (98.4%) sleep paralysis sufferers reported at least one psychological symptom (e.g., hallucinations) accompanying their last (or only) episode. A total of 190 sleep paralysis reporters and 221 controls who did not report sleep paralysis were further tested on a battery of instruments that assessed other sleep phenomena (e.g., nightmares), psychopathology, reported physical and sexual abuse, and imaginativeness. A composite index of imaginativeness predicted both the occurrence and frequency of sleep paralysis and also the intensity of sleep paralysis symptomatology. A salience hypothesis of sleep paralysis occurrence was developed to account for these findings.
Recent PET imaging and brain lesion studies in humans are integrated with new basic research findings at the cellular level in animals to explain how the formal cognitive features of dreaming may be the combined product of a shift in neuromodulatory balance of the brain and a related redistribution of regional blood flow. The human PET data indicate a preferential activation in REM of the pontine brain stem and of limbic and paralimbic cortical structures involved in mediating emotion and a corresponding deactivation of dorsolateral prefrontal cortical structures involved in the executive and mnemonic aspects of cognition. The pontine brainstem mechanisms controlling the neuromodulatory balance of the brain in rats and cats include noradrenergic and serotonergic influences which enhance waking and impede REM via anticholinergic mechanisms and cholinergic mechanisms which are essential to REM sleep and only come into full play when the serotonergic and noradrenergic systems are inhibited. In REM, the brain thus becomes activated but processes its internally generated data in a manner quite different from that of waking.
This paper describes a syndrome of psychological and physical symptoms involving body paralysis and hallucinations traditionally interpreted in Newfoundland as an attack of 'Old Hag'. Folk theories of cause and treatment are outlined based on 13 months of field research in a community on the northeast coast of Newfoundland. Data derived from the responses of 69 adults to the Cornell Medical Index (CMI) indicate that there are no significant differences in psychological or physical illness complaints between adults who have experienced the Old Hag and adults who have not had this experience. The striking similarity between the Old Hag experience and a clinical condition called sleep paralysis is analyzed, and the implications of viewing the Old Hag as sleep paralysis are discussed within the context of current theoretical issues in transcultural psychiatry.
Forty-four normal male students, aged 18-23 years were studied. After adaptation and baseline night (BN), 3 or 4 consecutive nights were interrupted by a forced awakening (10-90 min) once a night (ENs). Subjects (Ss) were awakened after they had slept for the first sleep cycle plus 20 min of NREM sleep in the 2nd cycle. The REM latencies following return to sleep showed a bimodal distribution separated by 25-30 min. The ENs were divided into 2 clusters: SOREMP (sleep onset REM period) and non-SOREMP nights. After interruption, the 2nd and the 3rd REM durations increased on non-SOREMP nights compared to SOREMP nights. We plotted, separately for SOREMP and non-SOREMP nights, the fluctuation of REM episode probability (FRP) at successive points in time. We examined the correspondence of FRPs derived from the sleep-independent, the sleep-dependent, and the reset hypotheses, with FRP of intact BN. On both SOREMP and non-SOREMP nights, none of the 3 models corresponded with BN. Thus, we suggest that, for both SOREMP and non-SOREMP nights, intervening wakefulness cancels the pre-awakening REM rhythm, and a new REM rhythm starts with or without SOREMP. We discuss factors influencing the rate of SOREMP occurrence (SOREMP %), such as circadian effect, individual differences, length of interruption, and pre-awakening NREM duration.
Imagination cannot conceive the horrors it [The Nightmare] frequently gives rise to, or language describe them in adequate terms . . . Everything horrible, disgusting or terrifying in the physical or moral world is brought before him in fearful array; he is hissed at by serpents, tortured by demons, stunned by the hollow voices and cold touch of apparitions . . . . At one moment he may have the consciousness of a malignant demon being at his side; then to shun the sight of so appalling an object, he will close his eyes, but still the fearful being makes its presence known; for its icy breath is felt diffusing itself over his visage, and he knows that he is face to face with a fiend. Then, if he looks up, he beholds horrid eyes glaring upon him, and an aspect of hell grinning at him with even more hellish malice. Or, he may have
Henry Fuseli painted "The Nightmare" in 1781 (see cover). The picture is dramatic, and it has been used to illustrate articles in professional journals. I believe the painting has several features of sleep paralysis, and my remarks are so directed.
Fuseli was an Anglo-Swiss painter and author, born in Zurich, Feb 7, 1741.1 His father was Johann Caspar Füssli, a court painter and town clerk. Henry Fuseli was educated at the Collegium Carolinum in Zurich. He started to study theology but left home because of problems stemming from a political publication. He went to Berlin, and then in 1764 to London on the recommendation of the British ambassador. The following year he translated into English J. J. Winckelmann's Reflections on the Painting And Sculpture of the Greeks. In 1770 he went to Italy to become a painter, having been encouraged by Sir Joshua Reynolds. He sent his first work
Despite reports of wide variation in the prevalence of sleep paralysis among different ethnic groups, there has never been any study in Chinese. In Hong Kong, a condition known as ghost oppression is descriptively identical to sleep paralysis. To examine this phenomenon, the response of 603 undergraduate students to a questionnaire were analyzed. Thirty-seven percent had experienced at least one attack of ghost oppression. There was no sex difference in the prevalence, and the peak age of onset was at the range of 17-19 for both sexes. A strong familial association was found and 20% of subjects reported a positive family history. Over one sixth of the subjects identified sleep disruption and stress as precipitating events.
Sleep paralysis is a common condition with a prevalence of 5-62%. Although most affected people have single or infrequent episodes, sleep paralysis may be recurrent, or occur in association with the narcoleptic syndrome. In a study of 22 subjects with frequent sleep paralysis and also excessive daytime sleepiness, episodes continued for between 5 and 35 years. In contrast to subjects with the narcoleptic syndrome, these patients did not have cataplexy, daytime sleepiness and insomnia were less severe, and there was no HLA DR2(15) or DQ1(6) association. Sleep paralysis was familial in 19 of these subjects. A non-HLA linked genetic factor, in addition to environmental factors, may thus predispose to sleep paralysis.
It is suggested that picturesque medical conditions can, at times, be encountered in literary works composed prior to their clinical delineation. This is true of sleep paralysis, of which the first scientific description was given by Silas Weir Mitchell in 1876. A quarter of a century earlier, Herman Melville, in Moby-Dick, gave a precise account of a case, including the predisposing factors and sexual connotations, all in accord with modern theory. The details of Ishmael's attack of sleep paralysis, the stresses leading up to it, and the associations causing him to recall the experience are given here.
Optimal human performance depends upon integrated sensorimotor and cognitive functions, both of which are known to be exquisitely sensitive to loss of sleep. Under the microgravity conditions of space flight, adaptation of both sensorimotor (especially vestibular) and cognitive functions (especially orientation) must occur quickly--and be maintained--despite any concurrent disruptions of sleep that may be caused by microgravity itself, or by the uncomfortable sleeping conditions of the spacecraft. It is the three-way interaction between sleep quality, general work efficiency, and sensorimotor integration that is the subject of this paper and the focus of new work in our laboratory. To record sleep under field conditions including microgravity, we utilize a novel system called the Nightcap that we have developed and extensively tested on normal and sleep-disordered subjects. To perturb the vestibular system in ground-based studies, we utilize a variety of experimental conditions including optokinetic stimulation and both minifying and reversing goggle paradigms that have been extensively studied in relation to plasticity of the vestibulo-ocular reflex. Using these techniques we will test the hypothesis that vestibular adaptation both provokes and is enhanced by REM sleep under both ground-based and space conditions. In this paper we describe preliminary results of some of our studies.
A sleep survey was conducted on 8162 citizens. The cumulative experience rate of sleep paralysis was 39.6%. The initial occurrence of sleep paralysis peaked at age 16 years. In addition to being higher in young people than in older subjects, the incidence of sleep paralysis was also higher among women than among men, and was significantly higher among shift worker than non-shift worker, and among persons engaged in the nursing profession than those not engaged in the nursing profession. The experience rate of sleep paralysis demonstrated a strong correlation with the frequency of dreaming, the experience rate of nightmares, times and regularity of going to bed and waking up, and particularly with the degree of insomnia.
Sleep paralysis (SP) entails a period of paralysis upon waking or falling asleep and is often accompanied by terrifying hallucinations. Two situational conditions for sleep paralysis, body position (supine, prone, and left or right lateral decubitus) and timing (beginning, middle, or end of sleep), were investigated in two studies involving 6730 subjects, including 4699 SP experients. A greater number of individuals reported SP in the supine position than all other positions combined. The supine position was also 3-4 times more common during SP than when normally falling asleep. The supine position during SP was reported to be more prevalent at the middle and end of sleep than at the beginning suggesting that the SP episodes at the later times might arise from brief microarousals during REM, possibly induced by apnea. Reported frequency of SP was also greater among those consistently reporting episodes at the beginning and middle of sleep than among those reporting episodes when waking up at the end of sleep. The effects of position and timing of SP on the nature of hallucinations that accompany SP were also examined. Modest effects were found for SP timing, but not body position, and the reported intensity of hallucinations and fear during SP. Thus, body position and timing of SP episodes appear to affect both the incidence and, to a lesser extent, the quality of the SP experience.
Sleep paralysis is an unusual neurologic phenomenon which may be described as "brief accesses of inability to move one's limbs, to speak and even to open one's eyes on awakening (hypnapompic or postdormital sleep paralysis) or more rarely when falling asleep (hypnagogic or predormital sleep paralysis)."11 The patient is fully aware of his state and has complete recall for the event. Sleep paralysis is occasionally preceded or accompanied by vivid and terrifying hallucinations in the pre- or postdormital stages of sleep. Rarely, it may be preceded by cataplexy. The paralysis always disappears suddenly, either spontaneously, after intense effort by the patient to "break" the paralysis, or after some sensory stimulation, such as being touched or spoken to. The duration of the episode is usually a few seconds, but may be a few minutes. The only sequelae are an occasional relapse into the paralyzed state if the patient does not
A total of 124 EEG examinations were performed in 75 narcoleptic patients. The routine EEGs were normal (abnormal slow waves being observed in less than 10%). The majority of the patients fell in drowsy state and sleep in the early part of the examination and about a half of them did so even during overbreathing.Polygraphic recording of the EEG, EKG, eye movements and respiratory movements were obtained in 34 examinations performed in 21 narcoleptics. An EEG pattern resembling that of drowsy state was found in 18 records in association with rapid eye movements (REM) at the sleep onset or several minutes after the onset.The patients often experienced sleep paralysis and/or hallucinations exclusively in the sleep onset REM period.During a cataplectic attack lasting for a brief period of about 30 sec, low voltage alpha rhythm was observed. Two other recordings obtained soon after the onset of and during cataplectic attacks which lasted several minutes indicated that the patients fell in the REM period soon after the onset of the attacks. The patients experienced hallucinations and/or dreams in the later parts of the attacks, which corresponded to the REM period. It would thus seem that cataplectic attacks are experienced in the transitional state from wakefulness to the REM period.The patients were in a similar or slightly higher level of consciousness in the early part of the sleep onset REM period than in drowsy state. In the REM period occurring several minutes after the sleep onset, they were in sleep, the depth of which corresponded to the sleep stages with spindles and high voltage slow waves. When the EEG pattern of the other sleep stages were observed, they were really in sleep, the depth of which was comparable to that of normal persons in the corresponding sleep stages.The EEG response to arousing stimuli were much decreased in the REM period as compared with those observed in the other sleep stages. In the early part of the sleep onset REM period as well as in the other part of the REM period the flash stimuli induced little or no EEG responses, although in the former period the patients were conscious of the stimuli and later recollected the correct number of them. In other sleep stages than the REM period the patients responded to and remembered only those but not all stimuli that induced marked arousal response in their EEGs.In conclusion, the basic disturbances characterizing narcoleptics are a persistent and intense inclination to fall in sleep and to fall into the REM period of sleep directly from wakefulness and at the sleep onset. Both, but predominantly the former, characterize sleep attacks, and the latter is manifested as cataplectic attacks, sleep paralysis and hypnagogic hallucinations.Narcolepsy is considered to be a disease not related to epilepsy.
Sleep paralysis accompanied by hypnopompic ('upon awakening') hallucinations is an often-frightening manifestation of discordance between the cognitive/perceptual and motor aspects of rapid eye movement (REM) sleep. Awakening sleepers become aware of an inability to move, and sometimes experience intrusion of dream mentation into waking consciousness (e.g. seeing intruders in the bedroom). In this article, we summarize two studies. In the first study, we assessed 10 individuals who reported abduction by space aliens and whose claims were linked to apparent episodes of sleep paralysis during which hypnopompic hallucinations were interpreted as alien beings. In the second study, adults reporting repressed, recovered, or continuous memories of childhood sexual abuse more often reported sleep paralysis than did a control group. Among the 31 reporting sleep paralysis, only one person linked it to abuse memories. This person was among the six recovered memory participants who reported sleep paralysis (i.e. 17% rate of interpreting it as abuse-related). People rely on personally plausible cultural narratives to interpret these otherwise baffling sleep paralysis episodes.
Sleep paralysis is one of the lesser-known and more benign forms of parasomnias. The primary or idiopathic form, also called isolated sleep paralysis, is illustrated by showing how patients from different cultures weave the phenomenology of sleep paralysis into their clinical narratives. Clinical case examples are presented of patients from Guinea Bissau, the Netherlands, Morocco, and Surinam with different types of psychopathology, but all accompanied by sleep paralysis. Depending on the meaning given to and etiological interpretations of the sleep paralysis, which is largely culturally determined, patients react to the event in specific ways.
This article presents an overview of the sleep paralysis experience from both a cultural and a historical perspective. The robust, complex phenomenological pattern that represents the subjective experience of sleep paralysis is documented and illustrated. Examples are given showing that, for a majority of subjects, sleep paralysis is taken to be a kind of spiritual experience. This is, in part, because of the very common perception of a non-physical 'threatening presence' that is part of the event. Examples from various cultures, including mainstream contemporary America which has no widely known tradition about sleep paralysis, are used to show that the complex pattern and spiritual interpretation are not dependent on cultural models or prior learning. This is dramatically contrary to conventional explanations of apparently 'direct' spiritual experiences, explanations that are summed up as the 'Cultural Source Hypothesis.' This aspect of sleep paralysis was not recognized through most of the twentieth century. The article examines the way that conventional modern views of spiritual experience, combined with medical ideas that labeled 'direct' spiritual experiences as psychopathological, and mainstream religious views of such experiences as heretical if not pathological, suppressed the report and discussion of these experiences in modern society. These views have resulted in confusion in the scientific literature on sleep paralysis with regard to its prevalence and core features. The article also places sleep paralysis in the context of other 'direct' spiritual experiences and offers an 'Experiential Theory' of cross-culturally distributed spiritual experiences.
Many thousands of people around the world firmly believe that they have been abducted by alien beings and taken on board spaceships where they have been subjected to painful medical examination.
Given that such accounts are almost certainly untrue, four areas of neuroscience are considered with respect to possible clues that may lead towards a fuller understanding of the alien abduction experience.
First, it is argued that sleep paralysis may be implicated in many such claims. Second, research into false memories is considered. It is argued that abductees may be more prone to false memories than the general population. Third, evidence is considered relating to the mental health of abductees. It is concluded that there is currently no convincing evidence for higher rates of serious psychopathology amongst abductees compared to the general population. However, abductees do seem to show higher levels on some potentially relevant measures (e.g., tendency to dissociate). Finally, claims that alien abduction experiences may be linked to abnormal activity in the temporal lobes is considered.
Although the neurosciences provide many clues to the nature of this bizarre experience, further research is required before a full understanding will be attained.