Sleep Paralysis

(redirected from Night demon)
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sleep paralysis

[′slēp pə‚ral·ə·səs]
(medicine)
Transient paralysis with spontaneous recovery occurring on falling asleep or on awakening.

Sleep Paralysis (Sleep Immobility)

(dreams)

Most people have had the experience of not being able to move in a dream. Being unable to run away from some kind of danger—or trying to run and being able to move only very slowly—is particularly common because at some level we know that we are paralyzed when we dream. During the rapid eye movement (REM) stage of sleep, when our most active dreams occur, a relay station at the top of the spinal column disconnects the motor cortex from the rest of the body, with the exception of the lungs and the eyes. This is why the neck muscles lose their tone during this stage, which is one of the defining characteristics of REM sleep.

Clearly this is a biological mechanism for preventing us from awakening otherwise we might thrash about during dreams. This disconnection of the motor impulses is the reason sleepwalking occurs only during non-REM sleep. It is also a factor in the sleep disorder referred to as sleep paralysis (which is distinct from normal REM sleep immobility), in which the sleeper is completely paralyzed immediately before entering (and sometimes immediately after leaving) sleep.

References in periodicals archive ?
Later, we were so shattered that not even the rather graphic drinks stirrers could bring out the hen night demons in us.
It has bags of atmosphere as you roam round a third person perspective 3D environment, plenty of night demons - like zombie (inset), werewolves and banshees - to destroy, and 15 different levels ranging from smart Chelsea to sewers.
It was believed that on this night demons, witches, hobgoblins and elves were released en masse to harass and oppress the living.