Cognitive Neuroscience Division, Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
Brain Behav. 2021 Jan;11(1):e01954. doi: 10.1002/brb3.1954. Epub 2020 Nov 18.
Past studies have found that healthy aging has a significant effect on the organization and function of networks in the human brain. Many of these studies have examined how functional connectivity during one task or at rest is affected by aging; however, few studies have systematically examined how the effect of age on functional connectivity may vary as a function of choice of in-scanner task.
The present study included healthy adults between the ages of 20 and 80 and examined a variety of metrics of functional connectivity during performance of 11 in-scanner tasks, falling into 4 cognitive domains: vocabulary, processing speed, fluid reasoning, and episodic memory. Functional connectivity was assessed at three levels: average correlations within and between 10 networks, system segregation (sensorimotor vs. association networks), and whole-brain graph theory metrics (global efficiency and modularity).
Results showed that the effect of age on these metrics differed as a function of task-for example, age had a more consistent effect on functional connectivity metrics computed during fluid reasoning tasks; however, there was less of an effect of age on functional connectivity metrics computed during tasks of episodic memory. Further, some of these measures showed relationships with behavioral performance on the in-scanner task, with different networks playing a role in the different cognitive domains.
These findings suggest that while aging may be generally associated with reductions in within- and between-network connectivity, system segregation, global efficiency, and modularity, the magnitude and presence of these effects varies by in-scanner task.
过去的研究发现，健康的衰老对人类大脑网络的组织和功能有显著影响。其中许多研究都考察了在一项任务或静息状态下功能连接如何受到衰老的影响；然而，很少有研究系统地研究了年龄对功能连接的影响如何随着扫描任务的选择而变化。
本研究包括年龄在 20 岁至 80 岁之间的健康成年人，并在执行 11 项扫描任务期间检查了各种功能连接的度量，这些任务分为 4 个认知领域：词汇、处理速度、流体推理和情景记忆。功能连接在三个层面进行评估：10 个网络内和网络间的平均相关性、系统分离（感觉运动与联想网络）和全脑图论度量（全局效率和模块性）。
结果表明，年龄对这些指标的影响因任务而异，例如，年龄对流体推理任务期间计算的功能连接指标的影响更为一致；然而，年龄对情景记忆任务期间计算的功能连接指标的影响较小。此外，这些措施中的一些与扫描任务中的行为表现相关，不同的网络在不同的认知领域中发挥作用。
这些发现表明，虽然衰老通常与网络内和网络间连接、系统分离、全局效率和模块性的减少有关，但这些影响的大小和存在因扫描任务而异。
