数学归纳推理和双手运动协作的fMRI研究

【作者】 王丹辉；

【导师】 陈华富；

【作者基本信息】 电子科技大学 ， 生物医学工程， 2011， 硕士

【摘要】 认知的研究在很长的一段时间内都是基于纯粹心理学的,随着实验方法的进步和影像技术的发展,我们已经能获得关于大脑结构与功能的重要信息,从而对认知现象错综复杂的神经生理机制有了更深的了解。本文就利用功能磁共振成像(functional Magnetic Resonance Image, fMRI)在数学归纳推理和双手运动协作任务中的应用,来探讨各自脑认知功能的潜在神经机制。数学归纳推理是重要的逻辑认知过程,为了探究其神经基础及实验任务难度与认知强度间的关系,我们设计了包含简单数学归纳推理、复杂数学归纳推理的任务组实验和数学计算的对照组实验,并对被试进行了fMRI数据的采集。成像结果表明简单数学归纳推理主要激活左侧角回,复杂数学归纳推理主要激活左侧额叶上回和双侧的角回。此外简单推理中左侧角回的激活强度与任务的难度系数有正相关性,复杂推理中左侧额上回的激活强度与任务的难度系数有正相关性。这些结果表明角回和额叶上回在不同难度的数学归纳推理任务中有着重要的作用:简单推理中的任务难度主要调节左侧角回所主管的认知成分,复杂推理中的任务难度主要调节额上回所主管的认知成分。在双手运动协作研究中,我们设计了包含交替运动协作和同步运动协作两个条件的手指敲击实验,并对被试进行了fMRI数据的采集。从脑功能激活和脑网络两个方面比较了两种运动协作任务的神经机制的异同,并分析了其产生的原因。根据结果我们有以下结论:两种任务的认知控制都需要额叶的计划和颞叶的节律性调节及运动区的执行来完成,但两种任务具有不同的认知控制机制。同步运动协作任务较交替协作任务需要更多的内在的运动感觉、描述和提取,更多更强的双手间信息交互,更多的实时的节律调节。也就是说,交替运动协作较同步运动协作简单且只需要计划好后执行,而同步运动协作在计划好后执行时,还需要更多的实时的调整。更多还原

【Abstract】 Cognition has been studied on the basis of psychology for a long time. With the progress of experimental method and the development of imaging technology, we have been able to learn much more about the complicated neural mechanism beyond the cognitive phenomenon by achieving anatomical and functional information of brain. In this thesis, we explored the neural basis of mathematical inductive reasoning and bimanual coordination by utilizing functional magnetic resonance imaging (fMRI).Mathematical inductive reasoning is an important logical cognition process. To clarify the neural mechanism of mathematical inductive reasoning and how the underlying neurobiological response varies with the difficulty in the reasoning tasks, we designed a fMRI experiment including simple and complex mathematical inductive reasoning as task and mental arithmetic as the baseline. The results demonstrated that simple mathematical inductive reasoning primarily activated the left angular gyrus of the brain, while complex mathematical inductive reasoning evoked both the left superior frontal gyrus and the bilateral angular gyrus. Furthermore, there was a significantly positive correlation between the difficulty of mathematical inductive reasoning tasks and active brain intensity of left angular gyrus for the simple mathematical inductive reasoning and the left superior frontal gyrus for the complex mathematical inductive reasoning. These findings indicate that the angular gyrus and left superior frontal gyrus play an important role in mathematical inductive reasoning with different difficulty: left angular gyrus modulates the cognition components related to the difficulty of simple mathematical inductive reasoning while the left superior frontal gyrus modulates the cognition components related to the difficulty of complex mathematical inductive reasoning.In the study of bimanual cooperation, we designed a fMRI experiment including alternate finger-tapping movement and synchronous finger-tapping movement. We compared the neural basis of the two bimanual coordination tasks from two aspects: functional brain activation and functional neural network, and we analyzed the reasons for the similarities and differences. The results suggested conclusion that both tasks were accomplished by the frontal plan and temporal modulation of rhythm but they owned different control way of movement cognition. Compared to alternate task, synchronous task need more inner motion perception, representation and retrieval, more and stronger interaction between the two hands, more on-line modulation of rhythm. That’s to say, alternate task could be performed as prior plan, synchronous task should be accomplished by combining prior plan and on-line modulation.更多还原