Hypnagogic hallucination refers to vivid dreamlike visions experienced by some patients of narcolepsy; a vivid , dreamlike intrusions into wakefulness that occur in the transition between wakefulness and sleep onset. Hypnagogic hallucination also refers to a vivid dreamlike hallucination that occurs as one is falling asleep. It is the opposite of an Hypnopompic hallucination which is a vivid dreamlike hallucination that occurs as one is waking up.
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Hypnagogic hallucination refers to a vivid dreamlike hallucination that occurs as one is falling asleep.