BACKGROUND Graph theory has been widely used to study structural and functional brain connectivity changes in healthy aging, and occasionally with clinical samples; in both cases, during task-related and resting-state experiments. Recent studies have focused their interest on dynamic changes during a resting-state fMRI register in order to identify differences in non-stationary patterns associated with the aging process. The objective of this study was to characterize resting-state fMRI network dynamics in order to study the healthy aging process. METHOD 114 healthy older adults were measured in a resting-state paradigm using fMRI. A sliding-window approach to graph theory was used to measure the mean degree, average path length, clustering coefficient, and small-worldness of each subnetwork, and the impact of age and time in each graph measure was assessed. RESULTS A combined effect of age and time was detected in mean degree, average path length, and small-worldness, where participants aged 75 to 79 showed a curvilinear trend with reduced network density and increased small-world coefficient in the middle of the register. CONCLUSION An effect of age was observed on average path length, with younger participants showing slightly lower scores.

中文翻译：

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静息状态功能动态连接和健康衰老：滑动窗口网络分析。

背景图论已被广泛用于研究健康老龄化过程中的结构和功能大脑连接变化，偶尔也用于临床样本；在这两种情况下，在任务相关和静息状态实验期间。最近的研究将他们的兴趣集中在静息状态 fMRI 记录期间的动态变化上，以识别与衰老过程相关的非平稳模式的差异。本研究的目的是表征静息态 fMRI 网络动力学，以研究健康的衰老过程。方法 114 名健康老年人在静息状态下使用 fMRI 进行测量。图论的滑动窗口方法用于测量每个子网的平均度、平均路径长度、聚类系数和小世界性，并且评估了每个图表测量中年龄和时间的影响。结果 在平均度数、平均路径长度和小世界性中检测到年龄和时间的综合效应，其中 75 至 79 岁的参与者显示出曲线趋势，网络密度降低，而登记册中间的小世界系数增加。结论 观察到年龄对平均路径长度的影响，年轻参与者的分数略低。