听觉认知相关的脑电处理及分析研究

发布时间：2018-03-20 14:11

本文选题：脑电　切入点：失匹配负波　出处：《清华大学》2013年博士论文　论文类型：学位论文

【摘要】：听力障碍为患者的日常生活带来了极大困扰，评估听觉认知能力可为临床疾病诊断和认知科学研究提供重要依据。本文基于脑电分析方法研究了听觉认知相关的若干问题。本文提出了从较少试次脑电数据中提取失匹配负波（Mismatchnegativity, MMN）的算法。利用事件相关电位（Event-related potential, ERP）和Gamma节律研究了噪声条件下视觉信息对语音识别的影响，并采用时空域结合分析的方法研究了语音识别时视听觉多感官增益成分的时间响应和空间定位。最后，初步探讨了临床中风患者噪声条件下的语音识别能力。提出了结合重采样差分和最大化信噪比的rdSIM算法，可以从较少试次脑电数据中提取MMN波形。算法能够最大化ERP信噪比，同时利用非参数重采样降低样本方差。差分可有效增强偏差和标准刺激响应的差异成分，直接提取差异波。结果表明，rdSIM算法能够从50个试次的偏差刺激数据中提取MMN波形，所得波形符合MMN的典型性质。基于脑电ERP研究不同信噪比环境下视觉输入对语音识别的影响。在-16、-12、-8、-4和0dB五种信噪比条件下，发现视听觉多感官增益随信噪比变化呈现倒U型，最大增益在信噪比-12dB。证实不同信噪比条件下视听觉多感官增益不完全符合反转原则，而与跨模态的随机共振现象一致。基于脑电Gamma节律信号研究不同信噪比环境下视听觉多感官增益的变化规律。发现Gamma频段视听觉相比单听的多感官增益在-12dB最大。在40~100ms时间窗内，视听觉Gamma节律的相位锁定能量、总能量和相位锁定因子同步增强，这表明Gamma节律的相位同步发挥着整合不同感官信息的作用。提出了结合rdSIM时空域模式和等效偶极子源分析的时空分析方法。采用rdSIM算法提取多感官增益的波形，，证实变化较大的幅度出现在N1/P2成分。再利用源定位技术分析多感官增益的脑区分布，结果证实多感官增益的脑活动分布在缘上回、角回、内顶叶沟和颞上沟。基于脑电ERP研究声音噪声环境下中风患者的语音识别能力。行为学和ERP的初步分析结果表明失语症患者视听觉多感官增益大于偏瘫非失语患者。提示失语患者可以从多感官增益中获益更大。
[Abstract]:Hearing impairment brings great trouble to patients' daily life. The evaluation of auditory cognitive ability can provide important basis for clinical disease diagnosis and cognitive science research. This paper studies some problems related to auditory cognition based on EEG analysis. An algorithm for extracting mismatched negative waves (MMN) is proposed. The effects of visual information on speech recognition under noise are studied by using event-related potentialand Gamma rhythms. The temporal response and spatial localization of the multi-sensory gain component of audiovisual perception in speech recognition were studied by the method of spatio-temporal domain combined with analysis. Finally, the speech recognition ability of clinical apoplexy patients under noise condition was preliminarily discussed. A rdSIM algorithm combining resampling difference and maximum SNR is proposed, which can extract MMN waveform from less subEEG data. The algorithm can maximize the SNR of ERP. At the same time, the nonparametric resampling is used to reduce the sample variance. Difference can effectively enhance the difference components of the deviation and standard stimulus response, and extract the difference wave directly. The results show that the MMN waveform can be extracted from the bias stimulus data of 50 samples. The obtained waveforms accord with the typical properties of MMN. The effects of visual input on speech recognition in different SNR environments were studied based on EEG ERP. Under five signal-to-noise ratio (SNR) conditions, it was found that the multi-sensory gain of audiovisual sense was inversely U-shaped under five signal-to-noise ratios (SNR) of -16 ~ (-12) -12 ~ (-8) ~ (-4) and 0 dB. The maximum gain is in the SNR of -12 dB. It is proved that the multi-sensory gain of the audiovisual sense does not fully conform to the inversion principle under different SNR conditions, but is consistent with the cross-modal stochastic resonance phenomenon. Based on EEG Gamma rhythmic signals, the variation of multisensory gain of audiovisual sense in different SNR environments was studied. It was found that the multisensory gain in Gamma band was maximum at -12 dB compared with that in single hearing, and in the time window of 40 ~ 100ms. The phase locking energy, total energy and phase locking factor of Gamma rhythm of audiovisual sense are enhanced synchronously, which indicates that phase synchronization of Gamma rhythm plays a role in integrating different sensory information. A spatio-temporal analysis method based on rdSIM spatio-temporal model and equivalent dipole source analysis is proposed. The multi-sensory gain waveform is extracted by rdSIM algorithm. The results showed that the distribution of multi-sensory gain was found in the superior marginal gyrus, the angular gyrus, the internal parietal sulcus and the superior temporal sulcus by using the source location technique, and the results showed that the brain activity of the multi-sensory gain was distributed in the superior marginal gyrus, the angular gyrus, the internal parietal sulcus and the superior temporal sulcus. The results of behavioral and ERP analysis showed that the auditory and visual multisensory gain of aphasia patients was higher than that of hemiplegic non-aphasia patients. The results suggested that aphasia patients had higher multi-sensory gain than those with hemiplegic non-aphasia. You can benefit more from multiple sensory gains.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：R764;TN911.7

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