年老化进程中双语经验影响执行功能及其脑机制
文献类型：学位论文
| 作者 | 陆冠琴 |
| 答辩日期 | 2022-06 |
| 文献子类 | 硕士 |
| 授予单位 | 中国科学院大学 |
| 授予地点 | 中国科学院心理研究所 |
| 其他责任者 | 李锐 |
| 关键词 | 双语经验 执行功能 脑结构 脑功能 老化 |
| 学位名称 | 理学硕士 |
| 学位专业 | 应用心理 |
| 其他题名 | The Influence of Bilingual Experience on Executive Function in Aging and the Underlying Brain Mechanism |
| 中文摘要 | Background：Aging is usually accompanied by cognitive decline. Accelerated cognitive decline will lead to neurodegenerative diseases such as Alzheimer's disease (AD). With the aging of the population, preventing and delaying the occurrence and development of AD has become a social concern. Recent studies have shown that bilingualism protect brain function, which is mainly reflected in delaying the decline of executive function and increasing the plasticity of brain structure and function. Learning and using an additional language may be an effective way to delay cognitive aging in the elderly. However, many studies failed to take the influenced factors of bilingualism (i.e., the individual's age, acquisition age of the second language, proficiency and frequency of usage) into account. In the present study, we overcame these limitations by analyzing the contribution of bilingualism on performance of executive function and the brain mechanism. In addition, we also explored the feasibility of bilingualism in preventing AD. Method: We explored the relationship between bilingualism and executive function based on the Human Connectome Project in Aging (HCP-A). We hypothesized that bilingualism protects against age-related cognitive deterioration and improves the plasticity on the structure and function in related brain regions, which may help to prevent the occurrence of AD. Multivariate variance analysis and t-test were used to compare the difference of executive function’s performance and the changes of age- related bilingual advantage between monolinguals and bilinguals. We also analyzed the differences of structure and function on the brain between them and calculated the correlation between the differences and the performances of executive functions. The possibility of bilingualism preventing AD was explored based on changes of FC in DMN and hippocampus. Results: (1) The results of performances on executive functions showed early acquisition age can better protect executive function. Compared with late bilinguals, the inhibition ability and cognitive flexibility of early bilinguals were significantly better and their bilingual advantages were significant in adults from 36 to 59 years old, especially in 45 to 59. (2) The results of brain structure showed bilinguals (especially in skilled bilinguals) increased the volume of gray matter and cortical thickness in DMN (i.e., angular gyrus and cuneus), frontal parietal network (FPN) (i.e., middle frontal gyrus, middle cingulate gyrus, inferior temporal gyrus, middle temporal gyrus), Somatomotor network (SMN) (i.e., precentral gyrus, postcentral gyrus, supplementary motor area) and gray matter volume in cerebellum, fusiform gyrus and putamen, which might help to improve the performance of executive function. The results of FC indicated that early bilinguals showed decreased FC in middle frontal gyrus, angular gyrus and inferior parietal lobule (IPL) compared to those later learners, and FC intensity in angular gyrus and middle frontal gyrus was negatively correlated with cognitive flexibility, which indicating that there were less neural resources involved in executive function in early bilingualism. Bilingualism increased the global efficiency of FPN such as middle frontal gyrus, inferior frontal gyrus and cingulate gyrus, which were significantly positively correlated with executive functions. The results showed that bilinguals rely on FPN to process language information and executive function. (3) The feasibility of bilingualism in preventing AD showed FC of bilinguals increased in left IPL and left hippocampus, also with left IPL and right hippocampus in early learners and left IPL and bilateral hippocampus in skilled learners. The results suggested that the increase of FC may be an internal neural mechanism to slow down cognitive decline and help to compensate for the decline of executive function caused by aging. Conclusion: The results further clarified that bilingualism delays the decline of executive function, and the early age of acquisition and early acquisition age has a better protective effect on executive function. The increase of gray matter volume and cortex thickness of DMN FPN SMN and the global efficiency of FPN may be the internal neural mechanism supporting bilingual advantages. The results of correlation analysis suggested that DMN and FPN may be brain mechanisms that coincide between language control and general cognitive control in bilinguals, and that the cerebellum, fusiform gyrus, and putamen may be specific brain regions that bilinguals engage in increased FC of IPL in DMN suggested that bilingualism may help to prevent AD. In a word, our findings provided evidence for bilingualism to increase brain reserve and protect against age-related cognitive deterioration. bilingual control different from those involved in general cognitive control. The increased FC of IPL in DMN suggested that bilingualism may help to prevent AD. In a word, our findings provided evidence for bilingualism to increase brain reserve and protect against age-related cognitive deterioration. |
| 英文摘要 | 背景：老化过程通常伴随着认知下降，过度的认知下降会导致阿尔茨海默病 （Alzheimer's disease，AD）等神经退行性疾病出现。随着人口老龄化，预防或延 缓 AD 的发生发展成为社会关注点。近年来研究表明，双语经验可以保护脑认知 功能，特别体现在延缓执行功能下降以及促进大脑结构和功能的改变，提示学习 二语可能是延缓老年人认知老化的有效途径，但以往研究普遍忽略了个体年龄、 第二语言习得年龄、熟练程度及使用频率等因素的影响。基于此，本研究在综合 考虑影响因素后，从行为和脑机制层面探查双语经验对老年人执行功能的影响， 并分析双语经验预防 AD 的可能性。 方法：本文基于人类连接组计划老年队列（Human Connectome Project in Aging，HCP-A）探讨双语经验与执行功能的关系。研究假设双语经验延缓执行 功能的下降，并促进与其相关脑区结构及功能的可塑性改变，这些变化可能有助 于预防 AD 的发生。本文采用多因素方差分析及 t 检验比较单、双语者之间执行 功能表现的差异以及双语者优势效应随增龄的变化；在脑结构和脑功能层面分析 两者之间的变化差异及其与执行功能表现的相关性；最后，基于 AD 靶点脑区 （海马和 DMN）分析双语经验预防 AD 相关脑区脑功能衰退的可能性。 结果：（1）行为方面：二语更早的习得年龄对执行功能有更好的保护作用。 与晚期双语者相比，早期双语者的抑制能力、认知灵活性及执行功能总体得分显 著要好，其优势效应在 36-59 岁（尤其是 45-59 岁）之间显著。（2）脑机制方面： ①脑结构方面，双语者（尤其是熟练双语者）DMN、额顶网络（Fronto-parietal, FPN）、感觉运动网络（Somatomotor network, SMN）脑区灰质体积和皮层厚度增 加以及小脑、梭状回、壳核等脑区灰质体积的增加可能有助于提高执行功能的表 现。其中 DMN 包括角回、楔叶；FPN 包括额中回、扣带回中部、颞下回、颞中 回等脑区；SMN 包括中央前回、中央后回。②功能连接（FC）方面，与晚期双 语相比，早期双语者额中回、角回、顶下小叶（Inferior parietal lobule，IPL）、楔 前叶脑区 FC 降低，其中角回与额中回 FC 强度与认知灵活性负相关显著，提示 早期双语者参与执行功能的神经资源可能相对较少。③脑网络属性方面，双语者 额中回、额下回、扣带回等 FPN 全局效率增加，并与执行功能相关显著，该结 果表明双语者依赖 FPN 处理语言信息和执行功能。（3）双语经验预防 AD：与单 语者相比，双语者左侧 IPL 与左侧海马 FC 增加；早期双语者左侧 IPL 与右侧海 马 FC 增加，且其 FC 值与执行功能相关显著；熟练双语者左侧 IPL 与双侧海马 FC 增加。该结果表明 FC 增加可能是减缓认知下降内在的神经机制，有助于补 偿老化所带来的执行功能下降。 结论：本研究结果进一步明确了双语经验延缓执行功能的下降，早期的习得 年龄对执行功能有更好的保护作用。DMN、FPN 及 SMN 灰质体积和皮层厚度以 及 FPN 全局效率的增加可能是支持双语优势效应内在的神经机制。DMN 中的 IPL 和海马 FC 增加提示双语经验可能有助于预防 AD。综上，我们的结果为双 语经验促进大脑储备增加和延缓认知老化提供了依据。 |
| 语种 | 中文 |
| 源URL | [http://ir.psych.ac.cn/handle/311026/43191]  |
| 专题 | 心理研究所_健康与遗传心理学研究室 |
| 推荐引用方式 GB/T 7714 | 陆冠琴. 年老化进程中双语经验影响执行功能及其脑机制[D]. 中国科学院心理研究所. 中国科学院大学. 2022. |
入库方式： OAI收割
来源：心理研究所
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