冷执行任务下精神分裂症患者脑电信号非线性动力学分析

发布时间：2019-02-26 17:39

【摘要】：精神分裂症是精神疾病中较为严重的一种,病因未明和症状复杂导致其诊断困难。目前,精神分裂症的诊断在很大程度上依赖于精神科医生的临床经验以及国内外的疾病分类手册(CCMD-3和DSM-IV-TR等),至今未有一种确切的客观的诊断标准。随着电生理学和数字信号处理技术的发展,脑电信号分析辅助精神分裂症诊断成为国内外学者研究热点。脑电信号是非线性的、复杂的信号,传统的线性分析方法不适用于其特征分析,故本文采用非线性动力学分析精神分裂症患者的脑电信号,寻找有效表征精神分裂症的非线性特征,以期建立精神分裂症诊断的一个相对客观的标准。精神分裂症的发病机理至今尚未清楚,但研究表明精神分类症有多种认知障碍,而执行功能障碍是最主要的认知障碍。执行功能可以分为两个方面:冷执行功能(Cool Executive Function)和热执行功能(Hot Executive Function)。其中,冷执行功能主要涉及反应抑制、注意和个体执行任务的有效性、灵活性,体现被试对任务的规划处理能力。冷执行功能不涉及情绪唤醒的内容,较为客观,故本文选择冷执行能力任务作为实验刺激。本文分别对17名首发未服药精神分裂症患者与对应的17名健康正常志愿者在三种冷执行任务(连线测验A、连线测验B和河内塔)状态下采集的多导联各波段脑电信号进行非线性动力学分析,计算其C0复杂度、分形维数和近似熵等非线性特征,分析首发精神分裂症患者与正常人脑电信号之间的差异,进而采用统计学分析和支持向量机分类器(SVM)验证其效果。结果显示,首发精神分裂症患者脑电信号更不规则、更复杂,在冷执行任务,特别是连线测试B任务下,近似熵与分形维数能够较好地揭示首发精神分裂症患者组与健康对照组脑电信号非线性动力学特征之间的差异,而C0复杂度的表征效果并不理想。因此,通过选择合适的非线性动力学算法分析患者在冷执行任务状态下的脑电信号能够较好地、客观地揭示精神分裂症患者抽象的认知功能障碍,为精神分裂症的诊断及治疗提供新的客观参考依据。
[Abstract]:Schizophrenia is one of the most serious mental diseases, which is difficult to diagnose because of unknown etiology and complicated symptoms. At present, the diagnosis of schizophrenia depends to a large extent on the clinical experience of psychiatrists and the domestic and foreign disease classification manuals (CCMD-3 and DSM-IV-TR, etc.), so far there is no definite objective diagnostic criteria. With the development of electrophysiology and digital signal processing technology, EEG analysis-assisted diagnosis of schizophrenia has become a hot research topic at home and abroad. The EEG signal is nonlinear and complex, and the traditional linear analysis method is not suitable for its characteristic analysis. Therefore, this paper uses nonlinear dynamics to analyze the EEG signal of schizophrenic patients. In order to establish a relatively objective criterion for the diagnosis of schizophrenia, we look for the nonlinear characteristics of schizophrenia. The pathogenesis of schizophrenia is still unclear, but studies have shown that there are many cognitive disorders in psychotaxonomy, and executive dysfunction is the most important cognitive disorder. The execution function can be divided into two aspects: the cold execution function (Cool Executive Function) and the hot execution function (Hot Executive Function). Among them, the cold execution function mainly involves the response inhibition, the effectiveness and flexibility of attention and individual task execution, which reflects the ability of the subjects to plan and deal with the task. Cold execution function does not involve the content of emotional arousal, so this paper chooses cold execution ability task as experimental stimulus. In this paper, 17 first-episode schizophrenic patients and 17 healthy volunteers were assigned three cold tasks (A, C), respectively. The nonlinear dynamic analysis of the multi-channel EEG signals collected under the state of connection test B and Hanoi tower was carried out, and the nonlinear characteristics such as C _ 0 complexity, fractal dimension and approximate entropy were calculated. The difference between the first-episode schizophrenic patients and normal EEG signals was analyzed, and the results were verified by statistical analysis and support vector machine classifier (SVM). The results showed that the EEG signals of the first-episode schizophrenic patients were more irregular and complex, especially in the cold task execution, especially under the B task of the wired test. Approximate entropy and fractal dimension can well reveal the difference between the first-episode schizophrenia group and the healthy control group in nonlinear dynamic characteristics of EEG signal, but the representation effect of C _ 0 complexity is not ideal. Therefore, by choosing a suitable nonlinear dynamic algorithm to analyze the EEG signals in the cold task state, we can objectively reveal the abstract cognitive dysfunction in schizophrenic patients. To provide a new objective reference for the diagnosis and treatment of schizophrenia.
【学位授予单位】：新乡医学院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R749.3

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