Parallel distributed processing and the emergence of schizophrenic symptoms.
Schizophrenia bulletin January 1, 1993 R E Hoffman, T H McGlashan
Schizophrenia may involve a breakdown in communication between different cortical areas of the brain. Evidence from psychotic states induced by phencyclidine, the adult form of metachromatic leukodystrophy, and neurometabolic studies supports this idea. A computer simulation of such brain pathology suggests two consequences: some cortical circuits become functionally autonomous, and a subset of these produce "parasitic foci" that repetitively reproduce the same cognitive output. These parasitic foci, located at different levels of language processing, are proposed to underlie symptoms such as delusions of control, paranoid delusions of the idee fixe type, thought broadcasting, auditory hallucinations, and certain deficit symptoms. A neurodevelopmental model of impaired corticocortical communication is described.