Dissociative symptoms and interregional EEG cross-correlations in paranoid schizophrenia.

Recent findings indicate that binding and synchronization of distributed activities are crucial for the mechanism of consciousness, and there is increased evidence that disruptions in feature binding produce disintegration of consciousness in schizophrenia. These data suggest that the disrupted binding and disintegration of consciousness could be related to dissociation, which is historically linked to Bleuler's concept of splitting in schizophrenia. In the present study we aimed to investigate relations among electroencephalogram (EEG) activities of cortical sites and used psychometric measures of positive and negative schizophrenia symptoms (Positive and Negative Syndrome Scale) and the Dissociative Experiences Scale (DES) in 58 patients with paranoid schizophrenia. The results show statistically significant Spearman correlations of the DES with cross-correlation function in nine (of 16) EEG pairs. Positive symptoms display significant Spearman correlation with mean of cross-correlation function in only one EEG pair (F4-C4). Results of the Mann-Whitney test between patients with higher (DES > or = 30) and lower dissociation show statistically significant differences between the groups for cross-correlations in nine EEG pairs. The results of this study provide the first supportive evidence for a negative relationship between cross-correlation indices and symptoms of dissociation in schizophrenia.