The hypnagogic state is the condition which exists between being awake and sleeping. For some people, this is a time of sensory hallucination, consisting of illusions of vision and sound.
Hallucination occurs at the onset of sleep before entering into REM. It is associated with vivid, sometimes bizarre imagery. It is thought that hypnagogic mentation is a greatly diminished version of REM sleep, allowing one to survey the contents of his or her subconscious at the level of awareness.
"Auditory hypnagogic phenomena include the hearing of crashing noises, one's name being called, a doorbell ringing, neologisms [new words or expressions], irrelevant sentences containing unrecognizable names, references to spoken conversations, remarks directed to oneself." (Mavromatis, 1987)
The hypnagogic speech phenomenon occurs when a person hears him/herself uttering words, which can be nonsensical or irrelevant, just as they are falling asleep.
Other reported sensory illusions include music, bangs and explosions. Inaccurate time perception, sensations of smell or taste, sensations of actively touching or being touched by someone or something, and hot or cold sensations, sometimes moving along the body, have also been reported during the hypnagogic state.
During the hypnagogic state, there is a decrease in normal thoughts and an increase in unusual, more dreamlike thoughts. People can experience brief and vivid imagery or sensations in one or more different sensory modalities. Many people who engage in new physical or mental activities for extended periods of time often experience a hallucinatory replay of the activities as they fall asleep.
Sleep starts, which are sudden brief muscle contractions in one or more parts of the body which occur at sleep onset, are another feature of hypnagogia. Sleep starts are sometimes associated with hypnagogic imagery, such as illusory sensations of movement or auditory phenomena.
Other sensations of movement may include floating, swinging, rocking, spinning,
and being in or on a moving vehicle. Bodily sensations may include, weightlessness, heaviness, tingling, numbness, shaking or vibrating,
and elongation of the body.
A sensation of falling seems to be the most commonly reported sensation of movement. The experience is often associated with a bodily jerk and visual imagery, such as falling off of a cliff.
Illusion of vision &
sound; sensory hallucination.
