The Unintegrated Right Cerebral Hemispheric Consciousness as Alien Intruder: A Possible Mechanism for Schneiderian Delusions in Schizophrenia?

Henry A. Nasrallah, Comprehensive Psychiatry, 1985, 26, 3, 273–282.

Abstract: The author proposes that one of the vital components of interhemispheric integration is the inhibition of any awareness by the verbally expressive hemispheric consciousness (usually the left) that it actually receives and sends thoughts, intentions, and feelings from and to another (right hemispheric) consciousness. This inhibition guarantees the unity of the right and left hemispheres into one “self” in the normal person. In schizophrenia, defective interhemispheric integration, probably neurochemical, may lead to disinhibition of the awareness by the left hemisphere that it is being “influenced” by an unknown “external force” which is fact the right hemisphere. Schneiderian delusions such as thought insertion and withdrawal and passivity feelings may be a direct outcome of such a deficit. Some lines of evidence and tests for the hypothesis are presented and discussed.