The hypnopompic state is the state of consciousness leading out of sleep, a term coined by the psychical researcher Frederic Myers. Its mirror is the hypnagogic state at sleep onset; though often conflated, the two states are not identical. The hypnagogic state is rational waking cognition trying to make sense of non-linear images and associations; the hypnopompic state is emotional and credulous dreaming cognition trying to make sense of real-world stolidity. They have a different phenomenological character. Hypnopompic and hypnagogic hallucinations are frequently accompanied by sleep paralysis, which is a state wherein one is consciously aware of one's surroundings but unable to move or speak. For this reason they are often frightening to a person newly experiencing them. These hallucinations are believed to be the source of many perceived supernatural experiences.