Neural complexity, dissociation and schizophrenia.

Background: Recent findings confirm, following Bleuler's and Janet's tradition, the significant influence of stress-related events and dissociation in the pathogenesis of schizophrenia. Dissociative reaction is most often a consequence of traumatic experiences that lead to a loss of inhibitory control and may produce split fragments of the mind. Recent findings in studies on brain complexity and neural synchronization suggest the hypothesis that the specific functional fragmentation of neural subsystems could be linked to the dissociation and splitting in schizophrenia that may be reflected in dynamic neural complexity and assessed by measures reflecting these processes.

Material/methods: In this context, the hypothesis tested in this study is that dynamic changes in electrodermal activity (EDA) as a measure of brain and autonomic activity could serve as an indicator of specific changes in neural complexity in schizophrenia patients. Therefore, bilateral EDA under rest conditions in 30 schizophrenic patients and 30 healthy subjects was measured.

Results: The results of nonlinear and statistical analysis of EDA records indicated increased neural complexity indexed by a point-wise correlation dimension (PD2) in schizophrenia patients compared with healthy controls.

Conclusions: This result represents preliminary support for the hypothesis that increased neural complexity reflects the functional fragmentation of neural subsystems related to traumatic dissociation and splitting in schizophrenia.