Electroencephalographic connectivity analysis in schizophrenia

•Our aim was to investigate electroencephalogram connectivity in schizophrenia.•We conducted a mutual information (MI) analysis in baseline and active conditions.•Patients with schizophrenia show a higher brain connectivity.•Controls show higher MI values in the baseline condition. This increased connectivity was not present in the patients group.•The results support the “dysconnection hypothesis” in schizophrenia. The aim of the present study was to further investigate the electroencephalogram (EEG) connectivity in schizophrenic patients by means of mutual information (MI), an analysis capable of detecting both the linear and nonlinear components of EEG. 19-lead EEGs were recorded in stable schizophrenic patients (N=17) and healthy controls (N=17) in two different conditions: closed eyes (CE) and open eyes (OE). In patients, higher MI values were observed in temporal-parietal-occipital regions compared with controls. In controls, an increase in brain connectivity in frontal regions was observed in the CE condition. This increase was not present in patients. Our results suggest that patients with schizophrenia present changes of brain connectivity that can be detected through MI analysis.