Sleep paralysis (SP) is a common occurence; due to its nature it carries strong cultural connotations and is often inscrutable to the ones who experience it. There is at present a paucity of studies in Taiwan on the topic and purpose of the present study is to probe the prevalence of SP in Taiwan and understand the psychological and demographic variables related to SP. The study surveyed 738 subjects between 20-80 years of The study found that sleep paralysis is a common phenomenon in Taiwan. Sleep paralysis may be related to education, occupation, and psychological diagnosis. In the process of sleep paralysis, subjects may experience various hallucinations (incubus, intruder, vestibular-motor hallucinations). These experiences are usually accompanied by heightened negative emotions and feelings.

INTRODUCTION 1
LITERATURE REVIEW 3
SLEEP PARALYSIS 3
FEATURES OF SLEEP PARALYSIS 4
SLEEP PARALYSIS AND PSYCHOLOGICAL VARIABLE 5
METHODS 7
PROCEDURE AND PARTICIPANTS 7
MEASURES 8
STATISTICAL ANALYSIS 8
RESULTS 11
PARTICIPANTS’ CHARACTERISTICS 11
PREVALENCE OF SLEEP PARALYSIS 13
SLEEP PARALYSIS HALLUCINATIONS 15
Incubus Hallucinations 15
Intruder Hallucinations 17
Vestibular-Motor Hallucinations 21
Other Hallucinations 23
EMOTIONS AND FEELINGS 25
OTHER FACTORS RELATED TO SLEEP PARALYSIS 27
Awake or Alertness 27
Eyes Open 27
False Awakenings 28
Position during Normal Sleep and Sleep Paralysis 29
Episode time of sleep paralysis 30
sleep paralysis and diagnosis 32
Sleep paralysis and demographic variables 34
Gender 34
Education Level 34
Occupation 36
DISCUSSION 39
LIMITATIONS 44
RECOMMENDATIONS 44
REFERENCES 47
APPENDIX A 53
APPENDIX B 54
APPENDIX C 64

Abrams, M. P., Mulligan, A. D., Carleton, R. N., & Asmundson, G. J. G. (2008). Prevalence and correlates of sleep paralysis in adults reporting childhood sexual abuse. Journal of Anxiety Disorders, 22(8), 1535-1541.
Andlauer O, Moore HE, Hong S-C, Dauvilliers Y, Kanbayashi T, Nishino S, et al. Predictors of hypocretin (Orexin) deficiency in narcolepsy without cataplexy.(2012).Sleep, 35,1247-1255.
American Academy of Sleep Medicine. The International Classification of Sleep Disorders, 3rd edn. American Academy of Sleep Medicine, Darien, IL, 2014.
Awadalla, A., Al-Fayez, G., Harville, M., Arikawa, H., Tomeo, M. E., Templer, D. I., & Underwood, R. (2004). Comparative prevalence of isolated sleep paralysis in Kuwaiti, Sudanese, and American college students. Psychological Reports, 95(1), 317-322.
Beck, A. T. & Steer, R. A. (2000). Beck Anxiety Inventory (BAI) Manual. (Y. J. Lin, Trans.). Taiwan, ROC: Chinese Behavioral Science Corporation.(Original work published 1993).
Beck, A. T., Steer, R. A. & Brown, G. K. (2000). Beck Depression Inventory-II (BDI-2) Manual.( S. Y. Chen, Trans.).Taiwan, ROC: Chinese Behavioral Science Corporation.(Original work published 1996).
Campling, J. (Ed.). (2009). SPSS for Social Scientists. London : Red Globe Press.
Cheyne, J. A. (2002). Waterloo Unusual Sleep Experiences Questionnaire –VIIIa Technical Report. Waterloo : Department of Psychology University of Waterloo.
Cheyne, J. A. (2003). Sleep Paralysis and the Structure of Waking-Nightmare Hallucinations. Dreaming, 13(3), 163-179.
Cheyne, J. A. (2005). Sleep paralysis episode frequency and number, types, and structure of associated hallucinations. European Sleep Research Society, 14, 319-324.
Cheyne, J. A., Rueffer, S. D., & Newby-Clark, I. R. (1999). Hypnagogic and hypnopompic hallucinations during sleep paralysis: Neurological and cultural construction of the night-mare. Consciousness and Cognition, 8(3), 319-337.
de Sa, J. F. R., & Mota-Rolim, S. A. (2016). Sleep Paralysis in Brazilian Folklore and Other Cultures: A Brief Review. Frontiers in Psychology, 7.
Denis, D. (2018). Relationships between sleep paralysis and sleep quality: current insights. Nature and Science of Sleep, 10, 355-367.
Denis, D., & Poerio, G. L. (2017). Terror and bliss? Commonalities and distinctions between sleep paralysis, lucid dreaming, and their associations with waking life experiences. Journal of Sleep Research, 26(1), 38-47.
Denis, D., French, C. C., & Gregory, A. M. (2017). A systematic review of variables associated with sleep paralysis. Sleep Medicine Reviews, 38, 141-157.
Denis, D., French, C. C., Rowe, R., Zavos, H. M. S., Nolan, P. M., Parsons, M. J., & Gregory, A. M. (2015). A twin and molecular genetics study of sleep paralysis and associated factors. Journal of Sleep Research, 24(4), 438-446.
Denis, D., French, C. C., Schneider, M. N., & Gregory, A. M. (2018). Subjective sleep-related variables in those who have and have not experienced sleep paralysis. Journal of Sleep Research, 27(5).
Dodet P, Chavez M, Leu-Semenescu S, Golmard J-L, Arnulf I.(2015). Lucid dreaming in narcolepsy. Sleep,38,487-497.
Glaziou, P. (2005) Sampsize. Retrieved from http://sampsize.sourceforge.net/iface/?fbclid=I
wAR3ivRuLGaUoVncb0Qcojirpi6i_0SVNg3fU9gpGTUSUfO_1WuDLjkhy57c#prev
Hsieh, S. W., Lai, C. L., Liu, C. K., Lan, S. H., & Hsu, C. Y. (2010). Isolated sleep paralysis linked to impaired nocturnal sleep quality and health-related quality of life in Chinese-Taiwanese patients with obstructive sleep apnea. Quality of Life Research, 19(9), 1265-1272.
Jalal, B., & Hinton, D. E. (2013). Rates and Characteristics of Sleep Paralysis in the General Population of Denmark and Egypt. Culture Medicine and Psychiatry, 37(3), 534-548.
Jalal, B., & Hinton, D. E. (2015). Sleep Paralysis Among Egyptian College Students Association With Anxiety Symptoms (PTSD, Trait Anxiety, Pathological Worry). Journal of Nervous and Mental Disease, 203(11), 871-875.
Jalal, B., & Ramachandran, V. S. (2014). Sleep paralysis and ‘‘the bedroom intruder’’: The role of the right superior parietal, phantom pain and body image projection. Medical Hypotheses, 83, 755-757.
Liskova, M., Janeckova, D., Kracmarova, L. K., Mlada, K., & Buskova, J. (2016). The occurrence and predictive factors of sleep paralysis in university students. Neuropsychiatric Disease and Treatment, 12, 2957-2962.
Nielsen TA, Laberge L, Paquet J, Tremblay RE, Vitaro F, Montplaisir J. Development of disturbing dreams during adolescence and their relation to anxiety symptoms. Sleep, 23(6), 1-10.
Ma, S. L., Wu, T., & Pi, G. F. (2014). Sleep paralysis in Chinese adolescents: A representative survey. Sleep and Biological Rhythms, 12(1), 46-52.
McNally, R. J., & Clancy, S. A. (2005). Sleep paralysis in adults reporting repressed, recovered, or continuous memories of childhood sexual abuse. Journal of Anxiety Disorders, 19(5), 595-602.
Munezawa, T., Kaneita, Y., Osaki, Y., Kanda, H., Ohtsu, T., Suzuki, H., ... Ohida, T. (2011). Nightmare and sleep paralysis among Japanese adolescents: A nationwide representative survey. Sleep Medicine,12(1),56-64.
Olunu, E., Kimo, R., Onigbinde, EO., Akpanobong, MA., Enang, IE., Osanakpo, M., Tom, M.I., Otohinoyi, A.D., Fakoya, A.O.J. (2018). Sleep Paralysis, a Medical Condition with a Diverse Cultural Interpretation. International Journal of Applied and Basic Medical Research,8(3),137-142.
O'Hanlon, J., Murphy, M., & Di Blasi, Z. (2011). Experiences of sleep paralysis in a sample of Irish university students. Irish Journal of Medical Science, 180(4), 917-919.
Ohayon MM, Zulley J, Guilleminault C, Smirne S. (1999). Prevalence and pathologic associations of sleep paralysis in the general population. Neurology, 52(6), 1194-1194.
Ohayon MM, Sagales T. Prevalence of insomnia and sleep characteristics in the general population of Spain. (2010). Sleep Med, 11(10), 1010–1018.
Otsuka, Y., Kaneita, Y., Nakagome, S., Jike, M., Itani, O., & Ohida, T. (2017). Nightmares and sleep paralysis among the general Japanese population: a nationwide representative survey. Sleep and Biological Rhythms, 16(2), 187-195.
Otto, M. W., Simon, N. M., PowerS, M., Hinton, D., Zalta, A. K., & Pollack, M. H. (2006). Rates of isolated sleep paralysis in outpatients with anxiety disorders. Journal of Anxiety Disorders, 20(5), 687-693.
Paradis, C., Friedman, S., Hinton, D. E., McNally, R. J., Solomon, L. Z., & Lyons, K. A. (2009). The Assessment of the Phenomenology of Sleep Paralysis: The Unusual Sleep Experiences Questionnaire (USEQ). CNS Neuroscience & Therapeutics, 15, 220-226.
Prashant, K., Supriya, B. (2010). Sample size calculation. International Journal of Ayurveda Research ,1(1), 55-57.
Saegert,C.S., Adler, E,N., Bullock, E,H., Cauce, M,A., Liu, M, W., Wyche, F, K.(2006). Report of the APA Task Force on Socioeconomic Status. Washington, DC:American Psychological Association.
Sharpless, B. A. (2016). A clinician's guide to recurrent isolated sleep paralysis. Neuropsychiatric Disease and Treatment, 12, 1761-1767.
Sharpless, B. A., & Barber, J. P. (2011). Lifetime prevalence rates of sleep paralysis: A systematic review. Sleep Medicine Reviews, 15(5), 311-315.
Sharpless, B. A., & Grom, J. L. (2016). Isolated Sleep Paralysis: Fear, Prevention, and Disruption. Behavioral Sleep Medicine, 14(2), 134-139.
Sharpless, B. A., McCarthy, K. S., Chambless, D. L., Milrod, B. L., Khalsa, S. R., & Barber, J. P. (2010). Isolated Sleep Paralysis and Fearful Isolated Sleep Paralysis in Outpatients With Panic Attacks. Journal of Clinical Psychology, 66(12), 1292-1306.
Simard, V., & Nielsen, T. A. (2005). Sleep Paralysis-Associated Sensed Presence as a Possible Manifestation of Social Anxiety. Dreaming, 15(4), 245-260.
Solomonova, E., Nielsen, T., Stenstrom, P., Simard, V. r., Frantova, E., & Donderi, D. (2008). Sensed presence as a correlate of sleep paralysis distress, social anxiety and waking state social imagery. Consciousness and Cognition, 17, 49-63.
Szklo-Coxe, M., Young, T., Finn, L., & Mignot, E. (2007). Depression: relationships to sleep paralysis and other sleep disturbances in a community sample. European Sleep Research Society, 16, 297-312.
Terrillon, J.-C., & Marques-Bonham, S. (2001). Does Recurrent Isolated Sleep Paralysis Involve More Than Cognitive Neurosciences? Journal of Scientific Exploration, 15(1), 97-123.
Vernet C, Redolfi S, Attali V, Konofal E, Brion A, Frija-Orvoen E, et al.(2011). Residual sleepiness in obstructive sleep apnoea: phenotype and related symptoms. Eur Respir J,38, 98-105.
Waters, F., Moretto, U., & Dang-Vu, T. T. (2017). Psychiatric Illness and Parasomnias: a Systematic Review. Current Psychiatry Reports, 19(7).
Wing, Chiu, Leung & Ng. (1999). Sleep paralysis in the elderly. Journal of Sleep Research, 8, 151–155.
Wu, Shi-Yi (2020). Translation, development and validation of a questionnaire on sleep paralysis and associated nighttime experiences. Unpublished Master’s Dissertation, National Dong Hwa University.
Yeung, A., Xu, Y., & Chang, D. F. (2005). Prevalence and Illness Beliefs of Sleep Paralysis among Chinese Psychiatric Patients in China and the United States. Transcultural Psychiatry, 42(1), 135-145.