Structural and Functional Connectivity in the Dynamic Aging Brain

理由：在加拿大，65岁以上的人口数量在历史上首次超过了儿童(14岁以下)的数量。根据加拿大统计局的数据，到2036年，加拿大的老年人数量可能达到1090万。鉴于我们相对年龄分布的变化，目前迫切需要更好地了解随着个人年龄的增长而发生的变化，特别是考虑到绝大多数认知神经科学研究都集中在年轻人身上。与衰老相关的最广为人知的变化之一是认知能力的变化。这些变化被认为是正常的，也是意料之中的。然而，到目前为止，将认知变化与潜在的大脑结构和功能联系起来的研究，并没有将大脑概念化为一个相互关联的动态系统，未来的研究必须纳入结构和功能连接的先进措施。研究计划：我的研究计划的首要目标是使用先进的多模式成像方法了解人脑衰老的潜在神经相关性。我的NSERC发现资助计划将使用基于磁共振成像的结构和功能连接的测量来检查衰老和认知的脚手架理论。具体地说，这项研究将回答以下问题：大脑连接的微观结构特征如何随着年龄的变化而变化？随着年龄的增长，功能网络是变得更活跃还是变得更不活跃？这些结构和功能连通性的变化与认知有何关系？某些变量，如性别、压力或体力活动，是否会导致大脑中神经可塑性的积极或消极变化？当我们跟踪一组人的衰老过程时，结构和功能的连通性及其与认知的关系如何随着时间的推移而变化？综上所述，这一全面而极其新颖的研究计划将描述作为一个动态系统的人脑如何随着年龄的变化而变化。这项工作将对当前的老龄化理论进行质询和推进，并增强对我国老龄化人口的当前认识。

Rationale: In Canada, the number of individuals over age sixty-five has exceeded the number of children (under age fourteen) for the first time in history. According to Statistics Canada, the number of seniors in Canada could reach 10.9 million by 2036. Given the shift in our relative age distribution, there is currently a crucial need to better understand the changes that occur as individuals age, especially given that the vast majority of cognitive neuroscience research has focused on young adults. Among the most well-known shifts associated with aging are changes in cognitive ability. These changes are considered normal and are to be expected. However, the research to date that has linked cognitive change to underlying brain structure and function, has not conceptualized the brain as a interconnected and dynamic system and it is essential for future research to incorporate advanced measures of structural and functional connectivity. Research Program: The overarching goal of my research program is to understand the underlying neural correlates of aging in the human brain using advanced multimodal imaging methods. My NSERC Discovery Grant program will use magnetic resonance imaging based measures of structural and functional connectivity to examine the Scaffolding Theory of Aging and Cognition. Specifically, this research will answer the following questions: How do microstructural characteristics of the brain's connections change with age? Do functional networks become more or less active as we age? How do these changes in structural and functional connectivity relate to cognition? Do certain variables such as sex, stress, or physical activity lead to positive or negative neuroplastic changes in the brain? How do structural and functional connectivity and their relationship with cognition change over time, as we follow one set of individuals through the aging process?  Taken together, this comprehensive and extremely novel program of research will characterize how the human brain as a dynamic system changes with age. The work will interrogate and advance current theory on aging, and enhance current understanding of our aging population.