Touch feel illusion in schizophrenic patients

Background: The rubber hand illusion is a tactile sensation referred to as an alien limb, The illusion has been explained by a spurious reconciliation of visual and tactile inputs reflecting functional connectivity in the bl ain and was used to explore alterations of functional connectivity in schiz ophrenia. Methods: The rubber hand illusion was achieved when two paintbrushes simult aneously stroke the hand of the subject hidden from vision by a screen, as well as an artificial hand placed in view of the subject. The rubber hand i llusion was assessed with a questionnaire affirming or denying the occurren ce of the illusion. Results: Schizophrenic subjects felt the illusion stronger and faster then did normal control subjects. Some rubber hand illusion effects col-related with positive symptoms of schizophrenia but not with negative symptoms, Conclusions: Altered functional integration of environ mental inputs could constitute the basis for erroneous interpretations of reality, such as delu sions and hallucinations. (C) 2000 Society of Biological Psychiatry.