Marquis d'Hervey de Saint-Denys was probably the first person to argue that it is possible for anyone to learn to dream consciously. In 1867, he published his book Les Reves et les Moyens de Les Diriger; Observations Pratiques (Dreams and How to Guide them; Practical Observations), in which he documented more than twenty years of his own research into dreams.
The term "lucid dreaming" was coined by Dutch author and psychiatrist Frederik van Eeden in his 1913 article A Study of Dreams. This book was highly anecdotal and not embraced by the scientific community. The term itself is considered by some to be a misnomer because it means much more than just "clear or vivid" dreaming. A better term might have been "conscious dreaming". On the other hand, the term 'lucid' was used by van Eeden in its sense of 'having insight', as in the phrase 'a lucid interval' applied to someone in temporary remission from a psychosis, rather than as referring to the perceptual quality of the experience, which may or may not be clear and vivid. To that extent van Eeden's phrase may still be considered appropriate.
In the 1950s the Senoi hunter-gatherers of Malaysia were reported to make extensive use of lucid dreaming to ensure mental health, although later studies refuted these claims.
Many people report having experienced a lucid dream during their lives, often in childhood. Children seem to have lucid dreams more easily than do adults. Although lucid dreaming is a conditioned skill, achieving lucid dreams on a regular basis can be difficult, even with training. Over time, several techniques have been developed to achieve a lucid dreaming state intentionally. The following are common factors that influence lucid dreaming, and techniques that people use to help achieve a lucid dream:
Dream recall is simply the ability to remember dreams. Good dream recall is often described as the first step towards lucid dreaming. Better recall increases awareness of dreams in general; with limited dream recall any lucid dreams one has can be forgotten entirely.
The main technique used to improve dream recall is to keep a dream journal, writing down any dreams remembered the moment one awakes. It is important to record the dreams as quickly as possible as there is a strong tendency to forget what one has dreamt. It is suggested that one's dream journal be recorded in the present tense. Describing an experience as if presently in it can help the writer to recall more accurately the events of their dream.
Dream recall can also be improved by staying still after waking up. This may be something to do with REM atonia (the condition of REM sleep in which the motor neurons are not stimulated and thus the body's muscles do not move). If one purposely prevents motor neurons from firing immediately after waking from a dream, recalling said dream becomes easier. Similarly, if the dreamer changes positions in the night they may be able to recall certain events of their dream by testing different sleeping positions.
Reality testing (also referred to as reality checking) is a common method used by people to determine whether or not they are dreaming. It involves performing an action with results that will be different if the tester is dreaming. By practicing these tests during waking life, one may eventually decide to perform one while dreaming, which will usually fail, hopefully letting the dreamer realize that he/she is dreaming.
Common reality tests include:
- Reading some text, looking away from the text, and reading it again - the text will probably have changed.
- Looking at one's watch (remembering the time), looking away, and looking back. As with the text, the time will probably have changed at the second glance.
- Flipping a light switch. Light levels rarely change in dreams.
- Looking into a mirror; in dreams, reflections from a mirror often appear to be blurred, distorted or incorrect.
- Plugging one's nose shut, and attempting to breathe through it, or attempting to breathe underwater. It is usually possible to breathe while doing this because the tester is not actually plugging one's nose in real life.
- Looking at one's hands one or more times. Hands may look distorted, or grow additional fingers in a dream.
- Gripping and stretching a finger. In a dream, body image can become distorted, and pulling a finger can elongate it. Also, the number of fingers tends to shift when stared at.
- Jumping into the air. Gravity is often distorted in a dream state and floating, flying or "moon jumping" will occur.
- Looking around and seeing everything blurred, such as if you were underwater.
- Being able to move through solid objects like walls with minimal resistance.
Another form of reality testing involves identifying one's dream signs, clues that one is dreaming. Dream signs are often categorized as follows:
Action — The dreamer, another dream character, or a thing does something unusual or impossible in waking life, such as photos in a magazine or newspaper becoming 3-dimensional with full movement, or the common example of being able to fly. Context — The place or situation in the dream is strange, such as fictional characters and places showing up. Form — The dreamer, another character, or a thing changes shape, is oddly formed, or transforms. This may include the presence of unusual clothing or hair, or a third person view of the dreamer.
Awareness — A peculiar thought, a strong emotion, an unusual sensation, or altered perceptions. In some cases when moving one's head from side to side, one may notice a strange stuttering or 'strobing' of the image.
Cohesion — Sometimes the dreamer may seem to "teleport" to a completely different location in a dream, with no transition whatsoever.
Mnemonic induction of lucid dreams (MILD)
The MILD technique is a common technique used to induce a lucid dream at will by setting an intention, while falling asleep, to remember to recognize that one is dreaming, or to remember to look for dream signs when one is in a dream.
The wake-back-to-bed technique is often the easiest way to encourage a lucid dream. The method involves going to sleep tired and waking up five hours later. Then, focusing all thoughts on lucid dreaming, staying awake for an hour and going back to sleep while practicing the MILD method. A 60% success rate has been shown in research using this technique. This is because the REM cycles get longer as the night goes on, and this technique takes advantage of the best REM cycle of the night. Because this REM cycle is longer and deeper, gaining lucidity during this time may result in a more lengthy lucid dream.
Cycle adjustment technique (CAT)
The cycle adjustment technique, developed by Daniel Love, is an effective way to induce lucid dreaming. It involves adjusting one's sleep cycle to encourage awareness during the latter part of the sleep. First, the person wakes up 90 minutes before normal wake time until their sleep cycle begins to adjust. After this, the normal wake times and early wake times alternate. On the days with the normal wake times, the body is ready to wake up, and this increases alertness, making lucidity more likely.
Wake-initiation of lucid dreams (WILD)
The wake-initiated lucid dream "occurs when the sleeper enters REM sleep with unbroken self-awareness directly from the waking state". There are many techniques aimed at entering a WILD. The key to these techniques is recognizing the hypnagogic stage, which is within the border of being awake and being asleep. If a person is successful in staying aware while this stage occurs, he or she will eventually enter the dream state while being fully aware that it is a dream.
There are key times at which this state is best entered; while success at night after being awake for a long time is very difficult, it is relatively easy after being awake for 15 or so minutes and in the afternoon during a nap. Techniques for inducing WILDs abound. Dreamers may count, envision themselves climbing or descending stairs, chant to themselves, explore elaborate, passive sexual fantasies, control their breathing, counting their breaths to keep their thoughts from drifting, concentrate on relaxing their body from their toes to their head, allow images to flow through their "mind's eye" and envision themselves jumping into the image, to maintain concentration and keep their mind awake, while still being calm enough to let their body sleep.
During the actual transition into the dream state, one is likely to experience sleep paralysis, including rapid vibrations, a sequence of loud sounds and a feeling of twirling into another state of body awareness, "to drift off into another dimension". Also there is frequently a sensation of falling rapidly or dropping through the bed as one enters the dream state. After the transition there may be the sensation of entering a dark black room from which one can induce any dream scenario of one's choosing, simply by concentrating on it. The key to success is not to panic, especially during the transition, which can be quite sudden.
Lucid dream induction is possible by the use of a physical device. The general principle works by taking advantage of the natural phenomenon of incorporating external stimuli into one's dreams. Usually a device is worn while sleeping that can detect when the sleeper enters a REM phase and triggers a noise and/or flashing lights with the goal of these stimuli being incorporated into the dreamer's dream. For example flashing lights might be translated to a car's headlights in a dream.
A well known dream induction device is the Nova Dreamer which has been discontinued as of 2006. However, a newer version is being worked on, but as of now is not available. A European induction device known as the Rem dreamer is still in production.
Meditation, and involvement in a conscious focusing on activities can strengthen the ability to experience lucid dreams by making the person more susceptible to noticing small discrepancies of their surroundings. Hypnotism may also help one achieve lucidity.
Prolonging lucid dreams
One problem faced by people wishing to lucid dream is awakening prematurely. This premature awakening can be especially frustrating after investing considerable time into achieving lucidity in the first place. Stephen LaBerge proposed two ways to prolong a lucid dream. The first technique involves spinning one's dream body. He proposed that when spinning, the dreamer is engaging parts of the brain that may also be involved in REM activity, helping to prolong REM. The second technique is rubbing one's hands. This technique is intended to engage the dreamer's brain in producing the sensation of rubbing hands, preventing the sensation of lying in bed from creeping into awareness. LaBerge tested his hypothesis by asking 34 volunteers to either spin, rub their hands, or do nothing. Results showed 90% of dreams were prolonged by hand rubbing and 96% prolonged by spinning. Only 33% of lucid dreams were prolonged with taking no action.
Other associated phenomena
- Rapid eye movement (REM) During dreaming sleep the eyes move rapidly. Scientific research has found that these eye movements correspond to the direction in which the dreamer is "looking" in his/her dreamscape; this apparently enabled trained lucid dreamers to communicate the content of their dreams as they were happening to researchers by using eye movement signals. This research produced various results, such as that events in dreams take place in real time rather than going by in a flash.
- False awakenings In a false awakening, one suddenly dreams of having been awakened. Commonly in a false awakening the room is identical to the room that the person fell asleep in, with several small subtle differences. If the person was lucid, he/she often believes that he/she is no longer dreaming, and may start exiting their room etc. Since the person is actually still dreaming, this is called a "false awakening".
This is often a nemesis in the art of lucid dreaming because it usually causes people to give up their awareness of being in a dream, but it can also cause someone to become lucid if the person does a reality check whenever he/she awakens. People who keep a dream journal and write down their dreams upon awakening sometimes report having to write down the same dream multiple times because of this phenomenon. It has also been known to cause bedwetting as one may dream that they have awoken to go to the restroom, but in reality are still dreaming.
- Sleep paralysis During REM sleep the body is paralyzed by a mechanism in the brain, because otherwise the movements which occur in the dream would actually cause the body to move. However, it is possible for this mechanism to be triggered before, during, or after normal sleep while the brain awakens. This can lead to a state where a person is lying in his or her bed and he or she feels frozen. Hypnagogic hallucinations may occur in this state, especially auditory ones. Experiencing sleep paralysis is a necessary part of WILD.