Lucid dreams are dreams during which the dreamer is aware that they are dreaming.
During lucid dreams, 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.
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 a 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.
In 1913, Dutch psychiatrist and writer Frederik (Willem) van Eeden (1860–1932) coined the term ‘lucid dream‘ in an article entitled “A Study of Dreams“.
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.
Lucid dreaming was subsequently researched by asking dreamers to perform pre-determined physical responses while experiencing a dream, including eye movement signals.
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 stays 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 color 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 of 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.”
It has been suggested that those who suffer from nightmares could benefit from the ability to be aware they are indeed dreaming.
A pilot study performed in 2006 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.