Department of Psychiatry, University of Oxford, OX37JX, Oxford, UK.
Center for Music in the Brain, Aarhus University, 8000, Aarhus, Denmark.
Sci Rep. 2017 Jul 11;7(1):5135. doi: 10.1038/s41598-017-05425-7.
Growing evidence has shown that brain activity at rest slowly wanders through a repertoire of different states, where whole-brain functional connectivity (FC) temporarily settles into distinct FC patterns. Nevertheless, the functional role of resting-state activity remains unclear. Here, we investigate how the switching behavior of resting-state FC relates with cognitive performance in healthy older adults. We analyse resting-state fMRI data from 98 healthy adults previously categorized as being among the best or among the worst performers in a cohort study of >1000 subjects aged 50+ who underwent neuropsychological assessment. We use a novel approach focusing on the dominant FC pattern captured by the leading eigenvector of dynamic FC matrices. Recurrent FC patterns - or states - are detected and characterized in terms of lifetime, probability of occurrence and switching profiles. We find that poorer cognitive performance is associated with weaker FC temporal similarity together with altered switching between FC states. These results provide new evidence linking the switching dynamics of FC during rest with cognitive performance in later life, reinforcing the functional role of resting-state activity for effective cognitive processing.
越来越多的证据表明，静息状态下的大脑活动会缓慢地在一系列不同的状态中游走，此时整个大脑的功能连接（FC）暂时稳定在不同的 FC 模式中。然而，静息态活动的功能作用仍不清楚。在这里，我们研究了静息态 FC 的切换行为与健康老年人认知表现之间的关系。我们分析了 98 名健康成年人的静息态 fMRI 数据，这些成年人之前在一项针对 1000 多名 50 岁以上接受神经心理学评估的受试者的队列研究中被归类为表现最好或最差的群体之一。我们使用一种新方法，重点关注动态 FC 矩阵的主导特征向量所捕获的主导 FC 模式。以寿命、出现概率和切换特征来检测和描述反复出现的 FC 模式或状态。我们发现，较差的认知表现与 FC 时间相似性较弱以及 FC 状态之间的切换改变有关。这些结果为静息状态下 FC 的切换动力学与晚年认知表现之间的联系提供了新的证据，进一步证实了静息态活动在有效认知处理中的功能作用。
