Situational factors affecting sleep paralysis and associated hallucinations: position and timing effects

  title={Situational factors affecting sleep paralysis and associated hallucinations: position and timing effects},
  author={J. Allan Cheyne},
  journal={Journal of Sleep Research},
  • J. A. Cheyne
  • Published 1 June 2002
  • Psychology, Biology, Medicine
  • Journal of Sleep Research
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… 
Recurrent Isolated Sleep Paralysis
RISP episodes are sometimes referred to as “sleep paralysis with hypnagogic and hypnopompic hallucinations” referring to the occurrence of the hallucinations (and the paralysis) either pre- or postdormitally, respectively.
Timing of spontaneous sleep‐paralysis episodes
The results suggest that SP, rather than uniquely reflecting anomalous sleep‐onset rapid eye movement (REM) periods, may result from failure to maintain sleep during REM periods at any point during the sleep period.
Sleep paralysis in Italy: Frequency, hallucinatory experiences, and other features
It is found that Italians from the general population reported high lifetime rates of SP, prolonged duration of immobility during the event, and great fear of the experience, all of which were particularly elevated as compared to cultures where there are no such elaborate traditions of SP.
Sleep Paralysis, Sexual Abuse, and Space Alien Abduction
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
Relationships between sleep paralysis and sleep quality: current insights
  • D. Denis
  • Psychology, Medicine
    Nature and science of sleep
  • 2018
Future research needs to focus on longitudinal designs to disentangle the direction of effects and more typically employ a broader assessment of sleep paralysis that better captures associated features such as hallucinations, fear, and distress.
Sleep Paralysis Postepisode Distress
Sleep paralysis (SP) is a brief paralysis experienced when falling asleep or waking up. It is often accompanied by vivid imagery and extreme fear. In addition to the fear during episodes, people
Recurrent isolated sleep paralysis: Polysomnographic and clinical findings
RISP and NAR patients differ in critical HLA alleles and in key sleep variables such as sleep latency and REM latency, and while SOREM phases were abundant in narcoleptic patients, such events were extremely rare in RISP patients.
Sleeping Position, Dream Emotions, and Subjective Sleep Quality
This study was aimed to examine the relationship between sleeping positions, dream characteristics, and subjective sleep quality in normal subjects. Sixty-three healthy subjects (45 males and 18
Prevalence and Clinical Picture of Sleep Paralysis in a Polish Student Sample
It is shown that a significant proportion of students experience recurrent SP and that this phenomenon is associated with fear and physical discomfort, and the scale of the phenomenon requires a deeper analysis.
Parasomnias: An Updated Review
Initial management should focus on decreasing the potential for sleep-related injury followed by treating comorbid sleep disorders, and pharmacotherapy for other parasomnias is less certain, and further investigations are necessary.


Factors Related to the Occurrence of Isolated Sleep Paralysis Elicited During a MultiPhasic Sleep-Wake Schedule CIRCADIAN RHYTHMS
According to the American Sleep Disorder Association (780.562; ICSD), the criteria for sleep paralysis are a complaint of inability to move the trunk or limbs at sleep onset or upon awakening.
Isolated sleep paralysis elicited by sleep interruption.
Judging from the PSG recordings, ISP differs from other dissociated states such as lucid dreaming, nocturnal panic attacks and REM sleep behavior disorders.
Sleep apnea and body position during sleep.
AD is longer in REM than NREM, regardless of position, and AHI is higher on the back only in NREM; however, favoring the lateral decubitus position may not be as beneficial as previously thought in very obese patients.
Isolated sleep paralysis: a web survey.
Clinical similarities between the recurrent form of isolated SP and channelopathies (in particular, periodic paralyses) are discussed, and an activation of limbic system structures is suggested in order to explain some of the most common subjective experiences associated with SP.
Prevalence and pathologic associations of sleep paralysis in the general population
This study indicates that the disorder is often associated with a mental disorder, and users of anxiolytic medication were nearly five times as likely to report SP, even after the authors controlled for possible effects of mental and sleep disorders.
High prevalence of isolated sleep paralysis: kanashibari phenomenon in Japan.
In Japan, a set of experiences called kanashibari is considered identical with isolated sleep paralysis, and the peak occurred at an earlier age in women subjects than in men subjects.
Effect of sleep position on sleep apnea severity.
For 24 subjects of this sample, who occupied both major body positions during the evaluation night, the apnea index was found to be twice as high during the time spent sleeping on their backs as it was when they slept in the side position, suggesting sleep position adjustment may be a viable treatment for some nonobese sleep apnea patients.
Sleep position and sleep stages: evidence of their independence.
It is concluded that, while there are ontogenetic trends in sleep position preferences, sleep positions are independent of sleep stages and do not show consistent rhythmicity.
Hypnagogic and Hypnopompic Hallucinations during Sleep Paralysis: Neurological and Cultural Construction of the Night-Mare
A three-factor structural model of HHEs based on their relations both to cultural narratives and REM neurophysiology is developed and tested with several large samples and central features of the model developed here are consistent with recent work on hallucinations associated with hypnosis and schizophrenia.
Impaired circadian waking arousal in narcolepsy-cataplexy.
It was concluded that decreased daytime amplitude of a circadian arousal system was the most parsimonious explanation for the increased amount, broader temporal distribution and relative phase advance of day sleep in narcolepsy and that, as well, such a mechanism could explain a number of other features of the disease.