A propósito da leitura do livro de Michael Shermer, The Believing Brain: “Sleep paralysis is a type of lucid dream in which the dreamer, aware of the dream, also senses paralysis, pressure on chest, presence of a being in the room, floating, flying, falling, or leaving one’s body…”
Physiologically, sleep paralysis is closely related to REM atonia, the paralysis that occurs as a natural part of REM (rapid eye movement) sleep. Sleep paralysis occurs either when falling asleep, or when awakening. When it occurs upon falling asleep, the person remains aware while the body shuts down for REM sleep, and it is called hypnagogic or predormital sleep paralysis. When it occurs upon awakening, the person becomes aware before the REM cycle is complete (…)
(…) the paralysis may be accompanied by terrifying hallucinations (hypnopompic or hypnagogic) and an acute sense of danger. Sleep paralysis is particularly frightening to the individual because of the vividness of such hallucinations.
A mare or nightmare (Proto-Germanic: *marōn; Old English: mære; Old Norse: mara; German: Mahr; Dutch: nachtmerrie; Swedish: mara; Icelandic: mara; Faroese: mara; Danish: mare; Norwegian: mare/mara) is a spirit or goblin in Germanic folklore which rides on people’s chests while they sleep, bringing on bad dreams (or “nightmares”).