Functional Connectivity in Chronic Schizophrenia: An EEG Resting-State Study with Corrected Imaginary Phase-Locking

Area of Science:

• Neuroscience
• Psychiatry
• Biomarkers

Background:

• Schizophrenia is a complex disorder with altered brain functional connectivity.
• Electroencephalography (EEG) studies show inconsistent results due to volume-conduction effects.
• A novel functional connectivity metric, corrected imaginary phase locking value (ciPLV), minimizes these effects.

Purpose of the Study:

• To explore network dynamics in schizophrenia using ciPLV.
• To provide a more reliable estimate of sensor-space functional network connectivity.
• To identify potential biomarkers for chronic schizophrenia.

Main Methods:

• Cross-sectional design.
• Resting-state EEG recordings from 30 individuals with chronic schizophrenia and 30 healthy controls (aged 18-55).
• Analysis using corrected imaginary phase locking value (ciPLV).

Main Results:

• Schizophrenia shows excess theta power (4-8 Hz) in centroparietal regions.
• Significant alterations in inter- and intra-hemispheric connectivity were observed.
• Connectivity changes occurred between frontotemporal regions (theta band) and frontoparietal regions (beta/gamma bands).

Conclusions:

• Schizophrenia exhibits long-range electrophysiological connectivity abnormalities independent of spectral power.
• Distinct hemispheric differences in frontotemporo-parietal networks were noted.
• These alterations may serve as promising biomarkers for chronic schizophrenia.