【作者】 李黎；

【导师】 骆清铭；

【作者基本信息】 华中科技大学 ， 生物医学工程， 2007， 硕士

【摘要】 现代脑功能成像技术的出现使脑认知研究得到了突飞猛进的发展。目前科学界多采用单模式成像的方式得到脑功能活动时的代谢(血氧)信息或者神经电活动信息。而随着研究的需要,结合各种单模式成像方式的优点进行多模式成像获取同步代谢(血氧)与电活动信息,探索大脑活动神经-血管耦联机制已成为脑认知研究的热点。本文采用fNIRS/ERP(Near-infrared Spectroscopy, NIRS; Event-Related Potential, ERP)多模式成像技术对经典的认知心理学实验Stroop效应进行前额叶的成像研究,同步获取血氧信号与神经电信号,探索脑功能活动的神经-血管耦联机理。本文通过将研制的fNIRS探测电路与商用脑电系统整合,制成了多模式成像系统,并通过软件控制实现了近红外检测与脑电检测的同步。结合这两种成像技术的特点,本文设计了同时适用于光学检测慢信号系统与电生理检测快信号系统的Stroop实验范式。同时,针对近红外测量系统与脑电检测系统,分别使用VisualC++6.0语言与Presentation软件平台编写了实验范式,实现了任务呈现与行为数据记录。本文分别采用本实验室自行研制开发的近红外脑功能成像器与商用脑电检测系统对11名被试进行了预实验,分析行为数据与血氧、脑电检测结果,证明本文所设计的实验范式在前额叶产生了显著的Stroop效应,并确定多模式成像探测位置位于前额叶中线偏左的区域。基于预实验结果,本文使用fNIRS/ERP多模式成像系统进行了Stroop实验,并对同步实验结果进行了分析与讨论,发现血氧参数变化与脑电变化在时程上具有很好的对应关系,且血氧参数变化比电活动变化滞后约100~200ms。更多还原

【Abstract】 The research of cognition soared with the advent of modern functional brain imaging techniques. At the present time, most of the researchers use single mode imaging techniques to obtain information of changes in metabolism (hemoglobin) or neuronal activities. However, as the understanding of the brain function progresses, the multimode imaging techniques which combine the advantages of single mode imaging techniques are becoming focus of this field. With the multimode method, researchers get access to the information of changes in metabolism (hemoglobin) and neuronal activities simultaneously, which makes the research of neuron-vascular coupling feasible. In this paper, fNIRS/ERP(Near-infrared Spectroscopy, NIRS; Event-Related Potential, ERP)multimode imaging technique was employed to study the Stroop effect in the prefrontal cortex. And with the synchronal information of hemoglobin and neuron, the mechanism of neuron-vascular coupling was discussed.The home-made fNIRS circuit was combined with the commercial EEG recording system to form the fNIRS/ERP multimode imaging system. And the fNIRS measurement and the ERP recording were synchronized by software control.Due to the different characteristics of the two imaging techniques, an improved experiment paradigm of Stroop was designed, which not only conform with the fNIRS technique which measures slow signals but also the EEG/ERP recording technique which measures relatively quick signals. The VisualC++6.0 and Presentation were adopted to program the experiment procedure for fNIRS measurement and EEG/ERP recording respectively. The program presents the task according to the paradigm, meanwhile records the behavior data of the experiment.Two beforehand experiments which used a home-developed fNIRS imager and the commercial EEG/ERP recording system the same as the one in the multimode imaging system were conducted. According to the behavior and measurement results of 11 subjects in the experiments, the paradigm designed in this paper activated prominent Stroop effect in the prefrontal cortex, and the optimal area for the multimode imaging system to measure is in the left of the midline of prefrontal head.After the correctness of the paradigm and the optimal detecting area were confirmed, the fNIRS/ERP multimode imaging experiment was operated. The synchronal result of changes of hemoglobin and neuronal potential shows that the changes in the quantity of oxyhemoglobin and deoxyhemoglobin relate to the changes of potential on the scalp in time. And the former is 100~200ms lagged of the later.更多还原