Possessions Including Poltergeist: "Are You There, Madness?"

Beliefs involving the devil and possession figured in the nosography of mental illness that alienists gradually established during the 19th century. The description of this form of cenesthetic hallucination resulted in "the possessed" being viewed as patients, which protected them from the trials and punishments they so frequently faced in earlier centuries. According to psychologists, this illusion of mental duality is linked to impairment of introspective capacities. Current brain imaging suggests inappropriate activity of the default mode network, which interferes with attentional systems during the hallucinatory episode.