| Schizophrenia is a disabling psychiatric disorder seriously affecting human’s health. According to the WHO, schizophrenia is the world’s fourth leading cause of disability. With the developing of social civilization, people gradually pay more attention to schizophrenia. However, because the causes of schizophrenia are unclear and symptoms of this disease are complex, doctors are difficult to diagnose this disease. Thus, the best treatment moment of patients is delayed. Today, with the development of electrophysiology, EEG (electroencephalogram) signal is favored by many scholars and medical researchers for reasons of its non-invasive access and high time resolution.EEG signals are generated by the change of brain cortex neurons postsynaptic potential, and it contains plentiful important physiological information. Thus, based EEG to analysis schizophrenia patients is an important approach of schizophrenia diagnosis. This article is based on nonlinear dynamic theory, applying multi-channel analysis approach to study the alpha band connectivity of schizophrenic EEG. Because of the limitations of traditional methods, the multichannel based approach is applied to analysis the time-spatial characterize of schizophrenic EEG signals. Meantime, the connectivity of schizophrenic brain is indicated by the physical significance of the features of specific region. The results indicate that dimensional complexity and Omega complexity are adapt to analyze schizophrenic EEG. The methods we used could reflect the spatial synchronicity of schizophrenic EEG from different aspects. The methods applied in this paper are able to show the time-spatial information of EEG signals, and give comprehensive results. According to the results of our methods, we can get the abnormal regions of schizophrenic brain, find the threshold of valid features, and finally giving an objective and scientific result to help doctors to diagnose schizophrenic patients.In this study,62subjects are employed to record EEG signals. In order to give a comprehensive and reliable description of schizophrenic cortical EEG connectivity, the alpha band is used to study the connectivity from global, regional and local points of view. After features are extracted, two-tailed t-test and ROC curve are done on the above features to examine the differences between the two groups. Additionally, Two classic nonlinear dynamic algorithms, correlation dimension and Fisher information entropy, are employed to verify our algorithms. The multichannel analysis method we used can verify that schizophrenia patients have a weak connectivity in the information processing from different angles. Moreover, this functional disconnection is founded to be specific brain regions, and the aberrant regions in schizophrenia patients are anterior and left regions, and the electrodes in prefrontal and left temporal regions are the dominant channels caused schizophrenia patients’brain functional disconnected. |
