Hallucination

ALLUCINAZIONE. - A purely subjective perception, corresponding to no external objective reality; the individual projects outside himself the images existing in his mind, with such vividness as to believe them truly existent externally. Thus he sees things, animals, persons; hears noises and words; experiences tastes; has tactile impressions that exist only in his imagination. The hallucination may be causally connected with intoxications by alcohol (zoopsias of alcoholics), cocaine, hashish, etc., infectious diseases, particularly with high fever; it is a customary accompaniment of serious mental illnesses (epilepsy, paralytic dementia, schizophrenia, paranoia, manic-depressive forms); in persons with an overexcitable imagination it may occur in the state between waking and sleep. A grave disorder of the cognitive faculty, hallucination powerfully affects the practical activity of the subject, who is impelled to act in accordance with impressions believed to be real, performing actions and proceeding to acts of attack or defence whose motivation, possessing a purely subjective logic, does not ordinarily entail his moral responsibility. Giuseppe de Nismo