乐观特质的脑结构基础及其对焦虑的作用机制

发布时间：2018-07-02 07:54

本文选题：乐观特质 + 脑结构　；参考：《西南大学》2014年硕士论文

【摘要】：乐观特质是人类进化的产物,这个具有个体差异的变量在人类的经验中起着重要的作用。乐观特质和积极正性的期待有关,乐观的个体倾向于相信好的事情会发生在自己的身上或自己的目标可以实现。乐观特质和身心健康有着密切的关系。随着功能性磁共振(FMRI)技术的发展,使得我们可以在更精细的层面上研究乐观特质,在本研究中我们采用的是基于体素的形态学(VBM)的分析方法研究乐观特质的个体差异的脑结构基础(本研究主要关注脑区的灰质的体积)。焦虑是一种普遍存在的情绪体验,它指的是当个体面临一种不明原因的情境时产生的一种不愉快且不安的负性情绪。乐观的个体对未来充满积极的期待,当他们遇到困难时会以积极的心态应对,因此他们会体验到较少的焦虑；反之悲观的个体对未来抱有消极的态度,每当遇到困难和挫折时他们就会体验更多的焦虑。乐观特质是通过什么机制来影响着焦虑水平,针对这一问题也有着很多研究。这些研究主要是集中在行为层面的研究,它们通常关注于乐观特质是通过什么样的行为方式(如应对策略、心理防御机制、心理控制源和社会支持等)来影响焦虑的。在本研究中我们关注乐观特质和焦虑之间是否存在着神经机制,即乐观特质是否会通过某些脑区的功能来影响焦虑的水平。研究一中,我们招募374名西南大学健康的本科生或研究生作为我们的被试,每个被试完成修订版的生活取向量表(LOT-R)并参加了脑成像的扫描。生活取向量表是用来测量个体的乐观特质水平的,在脑成像的扫描过程中要求被试闭上眼睛休息,但不要睡着,不要想特殊的事情。其中15名被试的数据被剔除(头动过大或解剖结构异常,问卷做的不认真),最后359名被试的数据进行了最后的分析。本研究中主要是用LOT-R量表得分和脑结构图像做相关分析,探讨乐观特质的脑结构基础。研究结果表明乐观特质的得分和左侧丘脑延伸至海马旁回这个脑区的灰质体积成显著的正相关,即乐观特质水平越高的个体这个脑区的体积就越大。丘脑和情绪的管理有着密切的关系,乐观特质高的个体可能有着更好的情绪管理的能力；海马旁回和情绪性记忆和体验有关,乐观特质高的个体可能有着更积极的情绪体验。在研究二中,研究一中的359名被试均参与了实验,每个被试都完成自评焦虑量表(SAS)。自评焦虑量表是一种以自我报告的方式测量个体的最近一周的焦虑水平。在这个研究中我们主要采用中介分析的方法来探讨乐观特质和焦虑的关系。在本研究中我们把研究一中的结果脑区的灰质体积作为中介变量,乐观特质的得分作为自变量,焦虑的得分做为因变量。中介分析的结果表明研究一中的脑区的体积在乐观特质和焦虑关系中起着部分中介效应,即乐观特质是部分通过丘脑延伸至海马旁回这个脑区的体积变化来影响着焦虑水平的。这个结果表明乐观特质可能通过丘脑、海马旁回的功能影响着焦虑的水平的。本研究应用基于体素的形态学分析方法探测乐观特质的脑结构基础,结果表明乐观特质和左侧丘脑延伸至海马旁回这个脑区的灰质体积成显著的正相关。即乐观特质水平越高的个体,这个脑区的灰质体积越大。乐观特质水平高的个体可能有着更好的情绪管理的能力和更积极的情绪体验。本研究超越了小样本的限制,应用相关分析,探讨了乐观特质个体差异的脑结构基础,为乐观特质的研究提供了生理层面的证据。本研究还应用中介分析的方法探讨了乐观特质及其相关脑结构对焦虑的神经机制,结果表明乐观特质部分通过左侧丘脑延伸至海马旁回这个脑区的灰质体积影响焦虑的水平。乐观特质可能是通过丘脑的情绪管理功能和海马旁回的情绪体验、情绪性记忆功能影响着个体焦虑的水平。这个研究结果不仅为乐观特质和焦虑关系的研究提供了神经机制层面的证据,而且对人格特质和情绪情感关系的研究提供了新的思路。
[Abstract]:Optimism is the product of human evolution. This individual variable plays an important role in human experience. Optimism is related to positive and positive expectations. Optimistic individuals tend to believe that good things happen on themselves or their own goals can be realized. There is a close relationship between optimism and physical and mental health. Relationship. With the development of functional magnetic resonance (FMRI) technology, we can study optimism at a more precise level. In this study, we use a voxel based morphological (VBM) analysis method to study the brain structure basis of individual differences in optimistic traits (this study focuses mainly on the volume of gray matter in the brain region). A universal emotional experience, which refers to an unpleasant and unsettling negative emotion that occurs when an individual faces an unknown situation. An optimistic individual is full of positive expectations for the future, and when they encounter difficulties, they respond positively with a positive attitude, so they experience less anxiety; and vice versa. The body has a negative attitude towards the future. They experience more anxiety whenever they encounter difficulties and setbacks. What is the mechanism that affects the level of anxiety through the mechanism, and there are many studies on this problem. These studies focus on behavioral research, and they usually focus on what the optimistic trait is through. Behavior patterns (such as coping strategies, psychological defense mechanisms, psychological control sources, and social support) affect anxiety. In this study, we focus on whether there is a neural mechanism between optimism and anxiety, that is, whether the optimistic trait will affect the level of anxiety through the function of some brain regions.
In study one, we recruited 374 Southwestern University healthy undergraduates or graduate students as our subjects, each completed the revised version of the life oriented scale (LOT-R) and participated in a brain imaging scan. The life orientation scale was used to measure the level of optimism in the individual, and the subjects were asked to close their eyes during the scan of brain imaging. Rest, but don't fall asleep, don't think of something special. 15 of the subjects were excluded (head oversize or anatomic abnormality, the questionnaire was not serious), and the last 359 subjects were analyzed. This study mainly used the LOT-R scale score and the brain structure image analysis to explore the brain structure of the optimistic trait. The results show that the score of optimism is positively correlated with the volume of gray matter in the brain area of the parahippocampal gyrus, that is, the greater the volume of the brain area, the higher the level of optimism. The management of the thalamus and the mood is closely related, and the individuals with high optimism may have a better emotional tube. Parahippocampal gyrus is associated with emotional memory and experience. Individuals with high optimism may have more positive emotional experiences.
In the second study, 359 subjects in the study were all involved in the experiment. Each of the subjects completed the self rating Anxiety Scale (SAS). The self rating Anxiety Scale was a self-reported measurement of the anxiety level of the individual in the last week. In this study, we mainly used the method of mediating analysis to explore the relationship between optimism and anxiety. In this study, the volume of gray matter in the brain region of the study one is used as an intermediary variable, and the score of the optimistic trait is regarded as an independent variable, and the score of anxiety is used as the dependent variable. The result of the intermediary analysis shows that the volume of the brain area in the first part of the study plays a partial mediator effect in the optimistic trait and the anxiety relationship, that is, the optimistic trait is partly passed through. The changes in the volume of the thalamus extending to the paraphippocampal gyrus affect the level of anxiety. This results suggest that the optimistic trait may pass through the thalamus, and the function of the parahippocampal gyrus affects the level of anxiety.
This study uses a voxel based morphological analysis to detect the structural basis of the brain in an optimistic trait. The results show a significant positive correlation between the optimistic trait and the volume of gray matter in the brain region of the parahippocampal gyrus. That is, the higher the level of optimism, the larger the volume of the gray matter in this brain area. It may have better emotional management ability and more positive emotional experience. This study transcends the limitations of small samples and applies related analysis to explore the basis of the brain structure of individual differences of optimism, and provides physiological evidence for the study of optimism. The results show that the gray matter volume of the optimistic trait partly through the left thalamus to the parahippocampal gyrus affects the level of anxiety. The optimistic trait may be through the emotional management function of the thalamus and the emotional experience of the parahippocampal gyrus, and the emotional memory function affects the level of individual anxiety. The results of the study not only provide neural evidence for the study of the relationship between optimism and anxiety, but also provide new ideas for the study of personality traits and emotional relationships.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：B848

【参考文献】