A lucid dream is a dream during which the dreamer is aware that they are dreaming. During a lucid dream, the dreamer may gain some amount of control over the dream characters, narrative, and environment; however, this is not actually necessary for a dream to be described as lucid.
- 1 Etymology
- 2 History
- 3 Scientific research
- 4 Definition
- 5 Prevalence and frequency
- 6 Suggested applications
- 7 In popular culture
- 8 Risks
- 9 See also
- 10 References
- 11 Further reading
The term 'lucid dream' was coined by Dutch author and psychiatrist Frederik van Eeden in his 1913 article A Study of Dreams, though descriptions of dreamers being aware that they are dreaming predates the actual term. Frederik Van Eeden studied his personal dreams since 1896. He wrote down the most interesting ones, and, out of all these dreams, 352 were what is now known as “lucid dreams”. Throughout all the data he collected from dreaming, he created different names for different types of dreams. He named 7 different types of dreams: initial dreams, pathological, ordinary dreaming, vivid dreaming, demoniacal, general dream-sensations, and lucid dreaming. Frederick Van Eeden said the seventh type of dreaming, lucid dreaming, was the most interesting and worthy of the most careful observation of studies. Eeden studied lucid dreaming between January 20, 1898, and December 26, 1912. In this state of dreaming, Eeden explains that 'you are completely aware of your surroundings and are able to direct your actions freely, yet the sleep is stimulating and uninterrupted.'
Early references to the phenomenon are found in ancient Greek writing. For example, the philosopher Aristotle wrote: 'often when one is asleep, there is something in consciousness which declares that what then presents itself is but a dream'. Meanwhile, the physician Galen of Pergamon used lucid dreams as a form of therapy. In addition, a letter written by Saint Augustine of Hippo in 415 AD tells the story of a dreamer, Doctor Gennadius, and refers to lucid dreaming.
In Eastern thought, cultivating the dreamer's ability to be aware that he or she is dreaming is central to both the Tibetan Buddhist practice of dream Yoga, and the ancient Indian Hindu practice of Yoga nidra. The cultivation of such awareness was common practice among early Buddhists.
Philosopher and physician Sir Thomas Browne (1605–1682) was fascinated by dreams and described his own ability to lucid dream in his Religio Medici, stating: '...yet in one dream I can compose a whole Comedy, behold the action, apprehend the jests and laugh my self awake at the conceits thereof'.
Samuel Pepys in his diary entry for 15 August 1665 records a dream, stating: "I had my Lady Castlemayne in my arms and was admitted to use all the dalliance I desired with her, and then dreamt that this could not be awake, but that it was only a dream".
In 1867, the French sinologist Marie-Jean-Léon, Marquis d'Hervey de Saint Denys anonymously published Les Rêves et Les Moyens de Les Diriger; Observations Pratiques ('Dreams and the ways to direct them; practical observations'), in which he describes his own experiences of lucid dreaming, and proposes that it is possible for anyone to learn to dream consciously.
Some have suggested that the term is a misnomer because van Eeden was referring to a phenomenon more specific than a lucid dream. Van Eeden intended the term lucid to denote "having insight", as in the phrase a lucid interval applied to someone in temporary remission from a psychosis, rather than as a reference to the perceptual quality of the experience, which may or may not be clear and vivid.
In 1968, Celia Green analyzed the main characteristics of such dreams, reviewing previously published literature on the subject and incorporating new data from participants of her own. She concluded that lucid dreams were a category of experience quite distinct from ordinary dreams and said they were associated with rapid eye movement sleep (REM sleep). Green was also the first to link lucid dreams to the phenomenon of false awakenings.
In 1980, Stephen LaBerge at Stanford University developed such techniques as part of his doctoral dissertation. In 1985, LaBerge performed a pilot study that showed that time perception while counting during a lucid dream is about the same as during waking life. Lucid dreamers counted out ten seconds while dreaming, signaling the start and the end of the count with a pre-arranged eye signal measured with electrooculogram recording. LaBerge's results were confirmed by German researchers D. Erlacher and M. Schredl in 2004.
In a further study by Stephen LaBerge, four subjects were compared either singing while dreaming or counting while dreaming. LaBerge found that the right hemisphere was more active during singing and the left hemisphere was more active during counting.
Neuroscientist J. Allan Hobson has hypothesized what might be occurring in the brain while lucid. The first step to lucid dreaming is recognizing one is dreaming. This recognition might occur in the dorsolateral prefrontal cortex, which is one of the few areas deactivated during REM sleep and where working memory occurs. Once this area is activated and the recognition of dreaming occurs, the dreamer must be cautious to let the dream continue but be conscious enough to remember that it is a dream. While maintaining this balance, the amygdala and parahippocampal cortex might be less intensely activated. To continue the intensity of the dream hallucinations, it is expected the pons and the parieto-occipital junction stay active.
Using electroencephalography (EEG) and other polysomnographical measurements, LaBerge and others have shown that lucid dreams begin in the Rapid Eye Movement (REM) stage of sleep. LaBerge also proposes that there are higher amounts of beta-1 frequency band (13–19 Hz) brain wave activity experienced by lucid dreamers, hence there is an increased amount of activity in the parietal lobes making lucid dreaming a conscious process.
Paul Tholey, a German Gestalt psychologist and a professor of psychology and sports science, originally studied dreams in order to answer the question if one dreams in colour or black and white. In his phenomenological research, he outlined an epistemological frame using critical realism. Tholey instructed his probands to continuously suspect waking life to be a dream, in order that such a habit would manifest itself during dreams. He called this technique for inducing lucid dreams the Reflexionstechnik (reflection technique). Probands learned to have such lucid dreams; they observed their dream content and reported it soon after awakening. Tholey could examine the cognitive abilities of dream figures. Nine trained lucid dreamers were directed to set other dream figures arithmetic and verbal tasks during lucid dreaming. Dream figures who agreed to perform the tasks proved more successful in verbal than in arithmetic tasks. Tholey discussed his scientific results with Stephen LaBerge, who has a similar approach.
Other researchers suggest that lucid dreaming is not a state of sleep, but of brief wakefulness, or "micro-awakening". Experiments by Stephen LaBerge used "perception of the outside world" as a criterion for wakefulness while studying lucid dreamers, and their sleep state was corroborated with physiological measurements. LaBerge's subjects experienced their lucid dream while in a state of REM, which critics felt may mean that the subjects are fully awake. J Allen Hobson responded that lucid dreaming must be a state of both waking and dreaming.
Philosopher Norman Malcolm has argued against the possibility of checking the accuracy of dream reports, pointing out that "the only criterion of the truth of a statement that someone has had a certain dream is, essentially, his saying so."
Paul Tholey laid the epistemological basis for the research of lucid dreams, proposing seven different conditions of clarity that a dream must fulfill in order to be defined as a lucid dream:
- Awareness of the dream state (orientation)
- Awareness of the capacity to make decisions
- Awareness of memory functions
- Awareness of self
- Awareness of the dream environment
- Awareness of the meaning of the dream
- Awareness of concentration and focus (the subjective clarity of that state)
- The dreamer is aware that they are dreaming
- Objects disappear after waking
- Physical laws need not apply in the dream
- The dreamer has a clear memory of the waking world
Barrett found less than a quarter of lucidity accounts exhibited all four.
Subsequently, Stephen LaBerge studied the prevalence of being able to control the dream scenario among lucid dreams, and found that while dream control and dream awareness are correlated, neither requires the other. LaBerge found dreams that exhibit one clearly without the capacity for the other; also, in some dreams where the dreamer is lucid and aware they could exercise control, they choose simply to observe.
Prevalence and frequency
In 2016, a meta-analytic study by David Saunders and colleagues  on 34 lucid dreaming studies, taken from a period of 50 years, demonstrated that 55% of a pooled sample of 24,282 people claimed to have experienced lucid dreams at least once or more in their lifetime. Furthermore, for those that stated they did experience lucid dreams, approximately 23% reported to experience them on a regular basis, as often as once a month or more.
It has been suggested that sufferers of nightmares could benefit from the ability to be aware they are indeed dreaming. A pilot study was performed in 2006 that showed that lucid dreaming therapy treatment was successful in reducing nightmare frequency. This treatment consisted of exposure to the idea, mastery of the technique, and lucidity exercises. It was not clear what aspects of the treatment were responsible for the success of overcoming nightmares, though the treatment as a whole was said to be successful.
Australian psychologist Milan Colic has explored the application of principles from narrative therapy to clients' lucid dreams, to reduce the impact not only of nightmares during sleep but also depression, self-mutilation, and other problems in waking life. Colic found that therapeutic conversations could reduce the distressing content of dreams, while understandings about life—and even characters—from lucid dreams could be applied to their lives with marked therapeutic benefits.
Psychotherapists have applied lucid dreaming as a part of therapy. Studies have shown that, by inducing a lucid dream, recurrent nightmares can be alleviated. It is unclear whether this alleviation is due to lucidity or the ability to alter the dream itself. A 2006 study performed by Victor Spoormaker and Van den Bout evaluated the validity of lucid dreaming treatment (LDT) in chronic nightmare sufferers. LDT is composed of exposure, mastery and lucidity exercises. Results of lucid dreaming treatment revealed that the nightmare frequency of the treatment groups had decreased. In another study, Spoormaker, Van den Bout, and Meijer (2003) investigated lucid dreaming treatment for nightmares by testing eight subjects who received a one-hour individual session, which consisted of lucid dreaming exercises. The results of the study revealed that the nightmare frequency had decreased and the sleep quality had slightly increased.
Holzinger, Klösch, and Saletu managed a psychotherapy study under the working name of ‘Cognition during dreaming – a therapeutic intervention in nightmares’, which included 40 subjects, men and women, 18–50 years old, whose life quality was significantly altered by nightmares. The test subjects were administered Gestalt group therapy and 24 of them were also taught to enter the state of lucid dreaming by Holzinger. This was purposefully taught in order to change the course of their nightmares. The subjects then reported the diminishment of their nightmare prevalence from 2–3 times a week to 2–3 times per month.
In her book The Committee of Sleep, Deirdre Barrett describes how some experienced lucid dreamers have learned to remember specific practical goals such as artists looking for inspiration seeking a show of their own work once they become lucid or computer programmers looking for a screen with their desired code. However, most of these dreamers had many experiences of failing to recall waking objectives before gaining this level of control.
Exploring the World of Lucid Dreaming by Stephen LaBerge and Howard Rheingold (1990) discusses creativity within dreams and lucid dreams, including testimonials from a number of people who claim they have used the practice of lucid dreaming to help them solve a number of creative issues, from an aspiring parent thinking of potential baby names to a surgeon practicing surgical techniques. The authors discuss how creativity in dreams could stem from "conscious access to the contents of our unconscious minds"; access to "tacit knowledge" - the things we know but can't explain, or things we know but are unaware that we know.
In popular culture
Though lucid dreaming can be beneficial to a number of aspects of life, some risks have been suggested. People who have never had the experience of lucid dreaming may not understand what is happening when they first experience a lucid dream. The person who lucid dreams could begin to feel isolated from others due to feeling different. It could become more difficult over time to wake up from a lucid dream. Someone struggling with certain mental illnesses could find it hard to be able to tell the difference between reality and the actual dream.
Long term risks with lucid dreaming have not been extensively studied. 
- Kahan T.; LaBerge S. (1994). "Lucid dreaming as metacognition:implications for cognitive science". Consciousness and Cognition. 3 (2): 246–264. doi:10.1006/ccog.1994.1014.
- Adrienne Mayor (2005). Fossil Legends Of The First Americans. Princeton University Press. p. 402. ISBN 978-0-691-11345-6. Retrieved 29 April 2013.
The term "lucid dreaming" to describe the technique of controlling dreams and following them to a desired conclusion was coined by the 19th-century Dutch psychiatrist Frederik van Eeden.
- Lewis Spence; Nandor Fodor (1985). Encyclopedia of occultism & parapsychology. 2. Gale Research Co. p. 617. ISBN 978-0-8103-0196-2. Retrieved 29 April 2013.
Dr. Van Eeden was an author and physician who sat with the English medium Mrs. R. Thompson and was also ... 431) in which he used the term "lucid dream" to indicate those conditions in which the dreamer is aware that they are dreaming.
- "Frederik van Eeden". www.lucidity.com. Retrieved 2018-04-23.
- Frederik van Eeden (1913). "A study of Dreams". Proceedings of the Society for Psychical Research. 26.
- Eeden, Frederik. "A Study of Dreams". lucidity.com.
- Andreas Mavromatis (1987). Hypnogogia: The Unique State of Consciousness Between Wakefullness and Sleep. Routledge, Chapman & Hall, Incorporated. p. 96. ISBN 978-0-7102-0282-6. Retrieved 29 April 2013.
The lucid dream, a term coined by van Eeden himself, had already been noted by Aristotle who wrote that 'often when...
- Véronique Boudon-Meillot. Galien de Pergame. Un médecin grec à Rome. Les Belles Lettres, 2012.
- Hurd, Ryan (October 8, 2009). "Lucid Dreaming and Christianity: Entering the Light". Dream Studies Portal. Retrieved Mar 12, 2018.
- "Letter from St. Augustine of Hippo". Newadvent.org. Retrieved 2009-06-20.
- Tse-fu Kuan (2008), Mindfulness in Early Buddhism: New Approaches through Psychology and Textual Analysis of Pali, Chinese and Sanskrit Sources (Routledge Critical Studies in Buddhism)
- Religio Medici, part 2:11. Text available at http://penelope.uchicago.edu/relmed/relmed.html
- "Tuesday 15 August 1665". The Diary of Samuel Pepys.
- D'Hervey de Saint-Denys, Les Rêves et Les Moyens de Les Diriger; Observations Pratiques, Paris/Amyot. archived at: https://archive.org/details/lesrvesetlesmoye00herv
- Kelly Bulkeley (1999). Visions of the night: dreams, religion, and psychology. SUNY Press. p. 157. ISBN 978-0-7914-9798-2. Retrieved 29 April 2013.
The person most widely credited with coining the term "lucid dream" is Frederick Van Eeden, a Dutch psychiatrist who from 1898 to 1912 gathered reports of lucid dreams and performed experiments on his own abilities to have lucid dreams ...
- Blackmore, Susan (1991). "Lucid Dreaming: Awake in Your Sleep?". Skeptical Inquirer. 15: 362–370.
- "Lucid Dreaming Frequently Asked Questions Answered by Lucidity Institute". lucidity.com.
- Green, C. (1968). Lucid Dreams, London: Hamish Hamilton.
- Watanabe Tsuneo (March 2003). "Lucid Dreaming: Its Experimental Proof and Psychological Conditions". Journal of International Society of Life Information Science. Japan. 21 (1): 159–162.
The occurrence of lucid dreaming (dreaming while being conscious that one is dreaming) has been verified for four selected subjects who signaled that they knew they were dreaming. The signals consisted of particular dream actions having observable concomitants and were performed in accordance with a pre-sleep agreement.
- LaBerge, Stephen (1990). "Lucid Dreaming: Psychophysiological Studies of Consciousness during REM Sleep". In Richard R. Bootzin; John F. Kihlstrom; Daniel L. Schacter (eds.). Sleep and Cognition. Washington, D.C.: American Psychological Association. pp. 109–26. ISBN 978-1557982629.
- Laberge, S. (1980). Lucid dreaming: An exploratory study of consciousness during sleep. (PhD thesis, Stanford University, 1980), (University Microfilms No. 80-24, 691)
- LaBerge, S. (2000). "Lucid dreaming: Evidence and methodology". Behavioral and Brain Sciences. 23 (6): 962–63. doi:10.1017/S0140525X00574020.
- LaBerge, Stephen (1990). in Bootzin, R.R., Kihlstrom, J.F. & Schacter, D.L., (Eds.): Lucid Dreaming: Psychophysiological Studies of Consciousness during REM Sleep Sleep and Cognition. Washington, D.C.: American Psychological Association, pp. 109–26.
- LaBerge, Stephen; Levitan, Lynne (1995). "Validity Established of DreamLight Cues for Eliciting Lucid Dreaming". Dreaming 5 (3). International Association for the Study of Dreams.
- Erlacher, D.; Schredl, M. (2004). "Required time for motor activities in lucid dreams". Perceptual and Motor Skills. 99 (3 Pt 2): 1239–42. doi:10.2466/PMS.99.7.1239-1242. PMID 15739850. Archived from the original (Scholar search) on 2007-03-05. Cite uses deprecated parameter
- LaBerge S.; Dement W.C. (1982b). "Lateralization of alpha activity for dreamed singing and counting during REM sleep". Psychophysiology. 19: 331–32. doi:10.1111/j.1469-8986.1982.tb02567.x.
- Muzur A., Pace-Schott E.F.; Allan Hobson (November 2002). "The prefrontal cortex in sleep" (PDF). Trends Cogn Sci. 6 (11): 475–81. doi:10.1016/S1364-6613(02)01992-7. PMID 12457899. Archived from the original (PDF) on 2007-06-30. Cite uses deprecated parameter
- Hobson, J. Allan (2001). The Dream Drugstore: Chemically Altered States of Consciousness. Cambridge, Massachusetts: MIT Press. pp. 96–98. ISBN 978-0-262-58220-9.
- Ogilvie R.; Hunt H.; Sawicki C.; McGowan K. (1978). "Searching for lucid dreams". Sleep Research. 7: 165.
- Harms, R. (n.d.). "Polysomnography (sleep study). Definition". Retrieved April 21, 2014.
- LaBerge S., Levitan L., Dement W.C. (1986) Lucid dreaming: physiological correlates of consciousness during REM sleep. Journal of Mind and Behavior 7: 251(121)–8(8).
- Holzinger B.; LaBerge S.; Levitan L. (2006). "Psychophysiological correlates of lucid dreaming". Dreaming. 16 (2): 88–95. doi:10.1037/1053-0722.214.171.124.
- Tholey, Paul (1980). Erkenntnistheoretische und systemtheoretische Grundlagen der Sensumotorik aus gestalttheoretischer Sicht. In: Sportwissenschaft. 10, S. 7–35.
- Tholey, Paul (1983). Techniques for inducing and manipulating lucid dreams. Perceptual and Motor Skills, 57, 1983, pp. 79–90.
- Tholey, Paul, (1983). Cognitive abilities of dream figures in lucid dreams. In: Lucidity Letter, p. 71.
- Tholey, Paul (1991). Conversation Between Stephen LaBerge and Paul Tholey in July of 1989. B. Holzinger (ed.). Lucidity, 10(1&2), 1991, pp. 62–71.
- Schwartz, B.A.; Lefebvre, A. (1973). [Conjunction of waking and REM sleep. II Fragmented REM periods.] [in French] Revue d'Electroencephalographie et de Neurophysiologie Clinique, 3, 165–76.
- Hartmann, E. (1975). Dreams and other hallucinations: an approach to the underlying mechanism. In R.K. Siegal & L.J. West (Eds.), Hallucinations (pp. 71–79). New York: J. Wiley & Sons.
- J. Allan Hobson (October 2009). "The Neurobiology of Consciousness: Lucid Dreaming Wakes Up". Harvard Medical School. Retrieved Mar 12, 2018.
- Malcolm, N. (1959) Dreaming. London:Routledge and Kegan Paul
- Tholey, P. (1980). "Klarträume als Gegenstand empirischer Untersuchungen [Conscious Dreams as an Object of Empirical Examination]". Gestalt Theory. 2: 175–91.
- Tholey, P. (1981). "Empirische Untersuchungen über Klartraüme [Empirical Examination of Conscious Dreams]". Gestalt Theory. 3: 21–62.
- Holzinger B (2009). "Lucid dreaming – dreams of clarity". Contemporary Hypnosis. 26 (4): 216–224. doi:10.1002/ch.390.
- "DREAMING 2(4) Abstracts - The Journal of the Association for the Study of Dreams". asdreams.org.
- Saunders, David T.; Roe, Chris A.; Smith, Graham; Clegg, Helen (2016). "Lucid dreaming incidence: A quality effects meta-analysis of 50 years of research". Consciousness and Cognition. 43: 197–215. doi:10.1016/j.concog.2016.06.002. PMID 27337287.
- Spoormaker,-Victor-I; van-den-Bout,-Jan (October 2006). "Lucid Dreaming Treatment for Nightmares: A Pilot Study". Psychotherapy and Psychosomatics. 75 (6): 389–394. doi:10.1159/000095446. PMID 17053341.
Conclusions: LDT seems effective in reducing nightmare frequency, although the primary therapeutic component (i.e. exposure, mastery, or lucidity) remains unclear.
- Colic, M. (2007). "Kanna's lucid dreams and the use of narrative practices to explore their meaning." The International Journal of Narrative Therapy and Community Work (4): 19–26.
- Spoormaker, V.I.; van den Bout, J. (2006). "Lucid dreaming treatment for nightmares: a pilot study". Psychotherapy and Psychosomatics. 75 (6): 389–94. doi:10.1159/000095446. PMID 17053341.
- Spoormaker, V.I.; van den Bout, J.; Meijer, E.J.G. (2003). "Lucid dreaming treatment for nightmares: a series of cases". Dreaming. 13 (3): 181–86. doi:10.1037/1053-07126.96.36.199.
- "Holzinger, B., Klösch, G., & Saletu, B. (2012). Cognition in Sleep - A Therapeutic Intervention in Patients with Nightmares and Post-Traumatic Stress Disorder. 21st Congress of the European Sleep Research Society, 1, Retrieved April 21, 2014". akm.ch. Archived from the original on April 24, 2014. Cite uses deprecated parameter
- Barrett, Deirdre. The Committee of Sleep: How Artists, Scientists, and Athletes Use their Dreams for Creative Problem Solving ... and How You Can, Too. Hardback Random House, 2001, Paperback Oneroi Press, 2010.
- LaBerge, Steven; Rheingold, Howard (1990). "9". Exploring the World of Lucid Dreaming. Ballantine Books. ISBN 0-345-37410-X.
- Hiscock, John (July 1, 2010). "Inception: Christopher Nolan interview". Daily Telegraph. UK. Retrieved July 7, 2010.
- Cohut, Maria (September 14, 2018). "Lucid Dreaming: Controlling the stories of sleep". Medical News Today.
- "Is Lucid Dreaming Dangerous?".
- Aviram, Liat; Soffer-Dudek, Nirit (2018). "Lucid Dreaming: Intensity, But Not Frequency, Is Inversely Related to Psychopathology". Frontiers in Psychology. 9: 384. doi:10.3389/fpsyg.2018.00384. PMC 5875414. PMID 29623062.
To the best of our knowledge, this is the first study to explore, and demonstrate, a potential long-term risk following the use of LD induction techniques.
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- Blanken, C.M. den and Meijer, E.J.G. "An Historical View of Dreams and the Ways to Direct Them; Practical Observations by Marie-Jean-Léon-Lecoq, le Marquis d'Hervey-Saint-Denys". Lucidity Letter, 7 (2) 67–78; 1988. Revised Edition in: Lucidity,10 (1&2) 311–22; 1991.
- Conesa, Jorge (2003). Sleep Paralysis Signaling (SPS) As a Natural Cueing Method for the Generation and Maintenance of Lucid Dreaming. The 83rd Annual Convention of the Western Psychological Association. May 1–4, 2003. Vancouver, BC, Canada.
- Conesa, Jorge (2002). "Isolated Sleep Paralysis and Lucid Dreaming: Ten-year longitudinal case study and related dream frequencies, types, and categories". Sleep and Hypnosis. 4 (4): 132–42.
- Gackenbach, Jayne; Laberge, Stephen (1988). Conscious Mind, Sleeping Brain. New York: Plenum Press. ISBN 0306428490.
- Green, Celia; McCreery, Charles (1994). Lucid Dreaming: The Paradox of Consciousness During Sleep. London: Routledge. ISBN 0415112397.
- LaBerge, Stephen (1985). Lucid Dreaming. Los Angeles: J.P. Tarcher. ISBN 0874773423.
- Olson, Parmy (2012). "Saying 'Hi' Through A Dream: How The Internet Could Make Sleeping More Social". Forbes.
- Warren, Jeff (2007). "The Lucid Dream". The Head Trip: Adventures on the Wheel of Consciousness. Toronto: Random House. ISBN 978-0679314080.
- Tholey, Paul (1983). "Relation between dream content and eye movements tested by lucid dreams". Perceptual and Motor Skills, 56, pp. 875–78.
- Tholey, Paul (1988). "A model for lucidity training as a means of self-healing and psychological growth". In: J. Gackenbach & S. LaBerge (Eds.), Conscious mind, sleeping brain. Perspectives on lucid dreaming, pp. 263–87. London: Plenum Press.
- Tuccillo, Dylan; Zeizel, Jared; Peisel, Thomas (2013). A Field Guide to Lucid Dreaming: Mastering the Art of Oneironautics. Workman Publishing. ISBN 978-0761177395.
- Lucid dreaming can be induced by electric scalp stimulation, study finds
- A look at four psychology fads – a comparison of est, primal therapy, Transcendental Meditation and lucid dreaming at the Los Angeles Times