不同刺激物在视觉空间认知中的事件相关电位研究

发布时间：2018-01-11 00:22

本文关键词：不同刺激物在视觉空间认知中的事件相关电位研究　出处：《上海交通大学》2009年硕士论文　论文类型：学位论文

【摘要】： 视觉空间认知是人类认知的重要一部分。视觉空间认知有两个最主要的外在因素,视觉刺激和空间信息编码。本文对最简单的二维空间认知进行研究,并将两大类文字作为视觉刺激引入视觉空间认知的研究中。本文将正立和镜像的两大类文字,即字母和汉字,作为视觉刺激,并将他们编码在不同的视觉空间角度上,要求被试对不同空间角度下的文字做出正确的判断。本文记录了正常被试者在进行视觉空间任务操作时的脑电信号并获得了事件相关电位及其地形图,进行了独立分量分析以提取相关的事件相关电位的亚成分,并且比较了两大类视觉刺激在视觉空间认知任务中的对大脑活动机制的影响。实验结果表明,空间角度的增加会引起被试的反应时和错误率的增加,事件相关电位的P300成分随着空间角度的增加而逐渐减小,出现了幅度调制现象。相同的空间角度下,被试对汉字的反应时和错误率都要比字母的要大,但是旋转速度没有显著差异。通过事件相关电位的地形图可以看出,大脑的顶区在不同的空间角度都一直处于活跃状态。汉字顶区的活跃一直表现为半球均势,字母的大脑活跃则随着角度的增加逐渐偏向左侧顶区。对事件相关电位进行独立分量分析后在180°得到了两个极性相反的亚成分,表明P300成分中包含一个随着空间角度的增加而负向增加的亚成分。本文详细地比较了两大类刺激对视觉空间认知任务的影响,阐明了视觉空间认知的基本机制以及大脑的活跃区域,并尝试用独立分量分析来获得两个极性相反并且相互独立的亚成分,证明独立分量分析在获得P300成分亚成分的可行性,使得对视觉空间认知的机制研究更加透彻。
[Abstract]:Visual spatial cognition is an important part of human cognition. Visual spatial cognition has two main external factors, visual stimulation and spatial information coding. And two kinds of characters as visual stimuli are introduced into the study of visual spatial cognition. In this paper, the orthodox and mirrored characters, letters and Chinese characters, are used as visual stimuli, and they are encoded in different visual spatial angles. The subjects were asked to make a correct judgment on the characters from different spatial angles. In this paper, the EEG signals of the normal subjects were recorded and the event-related potentials and their topographic maps were obtained. Independent component analysis (ICA) was performed to extract the subcomponents of event-related potentials and the effects of two major types of visual stimuli on the mechanism of brain activity in visual spatial cognitive tasks were compared. The experimental results show that the increase of spatial angle will lead to the increase of reaction time and error rate, and the P300 component of event-related potential will gradually decrease with the increase of spatial angle. Under the same spatial angle, the response time and error rate of the subjects to the Chinese characters were higher than that of the letters. However, there is no significant difference in rotation speed. According to the topographic map of event-related potentials, the apical region of the brain has been active in different spatial angles. The activity of the top region of Chinese characters has always been shown as a hemispheric balance. On the other hand, the activity of the alphabetical brain gradually shifted to the left parietal region with the increase of the angle. Two opposite polar subcomponents were obtained at 180 掳by independent component analysis of event-related potentials. It is shown that the P300 component contains a subcomponent that increases negatively with the increase of the spatial angle. In this paper, the effects of two kinds of stimuli on visual spatial cognitive tasks are compared in detail, and the basic mechanism of visual spatial cognition and the active regions of the brain are clarified. The independent component analysis is used to obtain two subcomponents with opposite polarity and independent of each other, which proves the feasibility of independent component analysis in obtaining P300 component subcomponents. It makes the research on the mechanism of visual space cognition more thorough.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：R33

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