Dream Paralysis
Dream paralysis has often been a fearful experience for those who awake from a sleep and cannot move the body for the first few minutes of wakefulness. However, there is a very scientific explanation for dream paralysis.
This state sometimes is accompanied by hallucinogenic experiences that can create even more fear. The reason for these visual and auditory continuations of experience upon awakening is that there are still dream state brainwaves, even though the subject has left the realm of sleep, or REM. “…imagery is often the continuation of a dream. The sleeper’s eyes may even have opened, but the transition to the waking state is not yet complete,” according to George Constable, Editor In Chief of Dreams & Dreaming (1990).
The physiological experience of paralysis upon awakening is quite simple and easy to explain. When the dreamer enters REM, the body produces particular chemicals which cause the body to be temporarily paralyzed in order to keep the body from acting out the dreams because the brain is receiving messages that it is a real experience and therefore instructs the body to move. These messages for movement are blocked by bio-chemicals which are most particularly focused on large muscle groups. This was first discovered by Michel Jouvet, a French researcher. He found a way to block the process that causes muscular paralysis during REM in cats. It was not pretty, but the cats moved around in REM, acting out their dreams as if they were awake.
The frantic struggle to move upon awakening is futile and counterproductive, for it is precisely the commands to the large muscles that are particularly blocked. The twitches one observes in a person or animal who is in REM sleep are produced only by the small muscles that are last in line to receive the chemical block to their commands. In Jeremy Taylor’s book Where People Fly, And Water Runs Uphill (1992), he says, “Oddly enough, experience shows that the most effective way to ‘break the spell’ of dream paralysis is to make a face, because it is the small muscles of the face and neck that are least affected by the paralysis, and moving them voluntarily appears to be the easiest and most effective way to send the missed ‘signal’ to the endocrine system that the dream is over and it is time to restore command of the voluntary muscles to the cerebral cortex. It may even be the case that it is the unintentional facial expressions of distress and frustration that accompany the unsuccessful efforts to move that actually accomplish the release from the ‘spell’ of continuing paralysis in these circumstances.”
There are nerve cells in the brain stem called gigantocellular tegmental field (GTF) neurons that act as a switch that turns on REM. Another group of neurons in the brain stem, called locus coeruleus, act as an off switch. As the GTF cells reach peak activation there is a burst of REM and a dream begins. This is one product of the biochemical reactions that take place when dreams occur.
The second part of this paralysis process has to do with noradrenalin (sometimes called norepinephrine). The presence of noradrenalin in the bloodstream is the most crucial of the necessary elements needed to prevent the voluntary nervous system from responding to dream events with physical actions as would occur in a waking event. Noradrenalin neutralizes the nervous impulses to action. It responds to the signal that the REM switch has been “turned on” with the presence of the GTF neurons. Noradrenalin is constantly replenished throughout the REM cycle, for it dissipates very rapidly in the bloodstream and constantly must be reproduced. When the “off switch” is recognized with the presence of the locus coeruleus neurons in the brain stem, noradrenalin is no longer replenished and dissipates rapidly. The body returns to the normal state of control and command of the voluntary nervous system, fully capable of physical actions. Paralysis has to do with the fact that the noradrenalin didn’t dissipate as fast as the dreamer awoke.
Sleep studies and experiments have been conducted to collect research and test for the cause of sleep paralysis. According to scientific study, sleep Paralysis (also called dream paralysis) is a natural result of sleep. Oftentimes a sleeping person will twitch while in the hypnagogic state (this is called hypnagogic myoclonus). This is related to the feeling of paralysis that occurs when one wakes out of REM activity. One way to "cure" sleep paralysis is to move the muscles of the face as mentioned above.