Functional tests of the corpus callosum in schizophrenia

The corpus callosum, a cerebral commissure of 200,000,000 fibres, is thickened in chronic schizophrenia and several neuropsychological and neurophysiological techniques have suggested poor links between the two cerebral hemispheres. The interhemispheric conduction time across the corpus callosum, measured in 12 schizophrenics, using the ipsilateral/contralateral latency differences of the early somatosensory evoked response, was found to be effectively zero. It is suggested that schizophrenia is a split-brain condition akin to agenesis of the corpus callosum, unrecognized through the use of compensatory ipsilateral sensory pathways.