What is A lucid dream?
A lucid dream is a dream during which the dreamer is aware of being in a dream. The use of the adjective "lucid" as a synonym for "conscious" was introduced in 1867 by the French writer, sinologist, and oneirologist Léon d'Hervey de Saint-Denys in his work "Dreams and the ways to direct them". In the 1980s, the scientist Stephen LaBerge published experiments on lucid dreams and demonstrated that it is possible from the dream state to voluntarily send a signal in the form of predetermined eye movements.
Most lucid dreams occur during the rapid eye movement (REM) sleep phase. They can happen spontaneously or result from learning. Knowing that one is dreaming gives the dreamer the opportunity to exercise deliberate control not only over their actions but also over the dream content and its course.
The ability to recognize the dream state during sleep is mentioned in Buddhist texts in the 8th century AD. In the Western world, lucid dreaming has been studied in sleep laboratories since the late 1970s.
Definition of phenomena associated with lucid dreaming
Considering oneiric lucidity as a continuum has led researchers to associate various dream-related phenomena and states of consciousness close to lucid dreaming either by their similarity or by their occurrence in time.
Pre-lucid dreams
This term was introduced by Celia Green to describe certain dreams during which the subject doubts the reality of their environment without fully realizing that they are dreaming.
False awakening dreams
In a false awakening dream, the dreamer believes they have truly woken up when only a change in dream setting has occurred. False awakening dreams are rarely lucid and are frequently reported in proximity to lucid dreaming.
Sleep paralysis
Sleep paralysis is a parasomnia that occurs during falling asleep or waking up: the sleeper feels paralyzed, unable to move, speak; they may also experience visual, auditory, tactile, or kinesthetic hallucinations. This condition is due to the intrusion of rapid eye movement (REM) sleep during a transition between wakefulness and sleep and probably due to the fact that the abolition of muscle tone accompanying REM sleep is felt by the subject. It can be used to consciously enter a dream, and some methods of inducing lucid dreams aim to achieve this.
Out-of-body experiences
Some lucid dreams are characterized by the impression of leaving one's body and observing the environment from a distinct position from the latter. Comparable to "ecstatic trances" described in anthropology, to "out-of-body experiences" (OBEs) mentioned by parapsychology, similar experiences have been reported by many researchers like Celia Green, Charles McCreery, Paul Tholey, Tart, LaBerge, or Christian M. Bouchet. Several methods of inducing lucid dreaming are directed towards producing such a sensation. The concept of "astral travel," borrowed from the terminology of the Theosophical Society, is sometimes used to describe such a phenomenon.
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