1 University of Ottawa Faculty of Medicine , Ottawa, Canada .
2 Department of Biostatistics, Johns Hopkins University Bloomberg School of Public Heath , Baltimore, Maryland.
Brain Connect. 2017 Dec;7(10):635-642. doi: 10.1089/brain.2017.0533.
Functional connectivity in resting-state functional magnetic resonance imaging (rs-fMRI) has received substantial attention since the initial findings of Biswal et al. Traditional network correlation metrics assume that the functional connectivity in the brain remains stationary over time. However, recent studies have shown that robust temporal fluctuations of functional connectivity among as well as within functional networks exist, challenging this assumption. In this study, these dynamic correlation differences were investigated between the dorsal and ventral sensorimotor networks by applying the dynamic conditional correlation model to rs-fMRI data of 20 healthy subjects. k-Means clustering was used to determine an optimal number of discrete connectivity states (k = 10) of the sensorimotor system across all subjects. Our analysis confirms the existence of differences in dynamic correlation between the dorsal and ventral networks, with highest connectivity found within the ventral motor network.
静息态功能磁共振成像(rs-fMRI)中的功能连接自 Biswal 等人最初的发现以来受到了广泛关注。传统的网络相关度量标准假设大脑中的功能连接随时间保持稳定。然而,最近的研究表明,功能网络之间以及内部的功能连接存在稳健的时间波动,这对这一假设提出了挑战。在这项研究中,通过将动态条件相关模型应用于 20 名健康受试者的 rs-fMRI 数据,研究了背侧和腹侧感觉运动网络之间的这些动态相关差异。k-均值聚类用于确定所有受试者感觉运动系统的离散连接状态(k=10)的最佳数量。我们的分析证实了背侧和腹侧网络之间动态相关性的差异,腹侧运动网络中的连接最高。