Prominent figures from ancient to modern times have been fascinated by lucid dreams and have sought ways to better understand their causes and purpose.
[5] Psychologist Stephen LaBerge is widely considered the progenitor and leading pioneer of modern lucid dreaming research.
[16] In addition, a letter written by Saint Augustine of Hippo in AD 415 tells the story of a dreamer, Doctor Gennadius, and refers to lucid dreaming.
[25] 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.
[26] In 1973, the National Institute of Mental Health reported that researchers at the University of California, San Francisco, were able to train sleeping subjects to recognize they were in REM dreaming and indicate this by pressing micro switches on their thumbs.
Using tones and mild shocks as cues, the experiments showed that the subjects were able to signal knowledge of their various sleep stages, including dreaming.
[27] In 1975, Dr. Keith Hearne had the idea to exploit the nature of rapid eye movements (REM) to allow a dreamer to send a message directly from dreams to the waking world.
[30] 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.
[36] To continue the intensity of the dream hallucinations, it is expected the pons and the parieto-occipital junction stay active.
[37] 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.
[45] A study was conducted by Stephen LaBerge and other scientists to see if it were possible to attain the ability to lucid dream through a drug.
[46] Teams of cognitive scientists have established real-time two-way communication with people undergoing a lucid dream.
During dreaming they were able to consciously communicate with experimenters via eye movements or facial muscle signals, were able to comprehend complex questions and use working memory.
[52][53] 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.
[61] A 2015 study by Julian Mutz and Amir-Homayoun Javadi showed that people who had practiced meditation for a long time tended to have more lucid dreams.
The researchers also found that during a lucid dream, "levels of self-determination" were similar to those that people experienced during states of wakefulness.
Mutz and Javadi also have stated that by studying lucid dreaming further, scientists could learn more about various types of consciousness, which happen to be less easy to separate and research at other times.
A pilot study performed in 2006 showed that lucid dreaming therapy treatment was successful in reducing nightmare frequency.
[63] 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.
A 2006 study performed by Victor Spoormaker and Van den Bout evaluated the validity of lucid dreaming treatment (LDT) in chronic nightmare sufferers.
[68] The test subjects were administered Gestalt group therapy and 24 of them were also taught to enter the state of lucid dreaming by Holzinger.
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.
Those struggling with certain mental illnesses could find it hard to tell the difference between reality and the lucid dream (psychosis).
[75] Exiting sleep paralysis to a waking state can be achieved by intently focusing on a part of the body, such as a finger, and wiggling it, continuing the action of moving to then the hand, the arm, and so on, until the person is fully awake.