Investigating the Differentiation of Norm and Disorders of Schizophrenic Spectrum by Analysis of EEG Correlation Synchrony

Objectives: The goal of the study was to discover the integrated differences in electroencephalography (EEG) synchrony between healthy people and patients with schizophrenia illnesses.

Methods: In this investigation, EEG recordings were made under a state of quiet wakefulness with eyes closed for three groups of 8-15 year old adolescents: normal group and two groups of mental disorders in nosological categories F20 and F21 according to International Classification of Diseases (ICD)-10. We employed an alternate approach for assessing EEG synchrony based on correlation between EEG signal envelopes. This method has been shown to be a highly sensitive tool for distinguishing between psychopathological and functioning states in the past.

Results: The investigation revealed a complicated picture of major topographical, inter-hemispheric, regional, and age distinctions, in which many of the fragmentary results previously received by other researchers were confirmed. One of the basic features of the received integrated picture of pathology is existence of extended zones of sharply lowered EEG synchrony dividing local and isolated areas in frontal and occipital regions mainly of normal or sometimes increased EEG synchrony. The obtained results are perfectly consistent with the notion of cortical electric activity disintegration in schizophrenia spectrum diseases.

Conclusion: The technique used provides nearly 100 percent reliability of tripartite classification of norm and two pathology groups individually, it allows for the discovery of many authentic correlations between EEG synchrony estimations and psychometric indices, and its results are consistently reproducible for different groups of patients and examinees, opening up opportunities and prospects for its use as an auxiliary quantitative differential indicator.