Self talking is talking to oneself. The person talks without expecting any response. It may be the early symptoms of schizophrenia. Muttering to oneself for one or 2 days may not be pathological. If somebody laughs without any reason when alone or talking with himself for a prolonged period, along with other behavioral abnormalities like hallucination, social withdrawal, emotional upsets, odd behavior, etc. the person needs immediate psychiatric consultation.
Hallucination is a false perception in any of the five sensory modalities when no external stimulus exists, as when a nonexistent object is seen. Hallucinations may occur in the twilight state between sleeping and awakening, or in delirium, delirium tremens, or exhaustion; they also may be induced under hypnosis. The visual sense is most often affected. Persistent hallucinations are characteristic of schizophrenia. In one type of schizophrenia, victims believe that they hear accusing or commanding voices, to which they may react in panic, with abject obedience, or with attempts at self-protection or even suicide. Hallucination is distinguished from illusion, a false perception of an actual stimulus, and is common following self-administration of certain drugs such as mescaline, marijuana, and lysergic acid diethylamide (LSD). Both illusions and hallucinations can be drug induced.
Schizophrenia is a severe mental illness characterized by a variety of symptoms, including loss of contact with reality, bizarre behavior, disorganized thinking and speech, decreased emotional expressiveness, and social withdrawal. Usually only some of these symptoms occur in any one person. The term schizophrenia comes from Greek words meaning "split mind." However, contrary to common belief, schizophrenia does not refer to a person with a split personality or multiple personality. (For a description of a mental illness in which a person has multiple personalities.