Interhemispheric transfer of information and schizophrenia.

The interhemispheric transfer of stereognostic information was investigated in four groups of subjects: paranoid schizophrenics, non-paranoid schizophrenics, non-schizophrenic psychiatric patients, and normals. Previous work has raised the possibility that schizophrenia is characterised by a dysfunction of the corpus callosum, but there are several methodological problems associated with this research. A comparison of inter-manual and same-hand conditions on the experimental task revealed no evidence for impaired transfer of information in the schizophrenic groups. However, the performance of the non-paranoid schizophrenic group was markedly inferior to all other groups on the right hand/right hand no transfer condition, consistent with a left hemisphere dysfunction. Possible reasons for the failure to replicate previous findings are discussed.