College of Intelligence Science and Technology, National University of Defense Technology, Changsha, Hunan, China.
Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China.
Hum Brain Mapp. 2021 Apr 1;42(5):1416-1433. doi: 10.1002/hbm.25303. Epub 2020 Dec 7.
Until now, dynamic functional connectivity (dFC) based on functional magnetic resonance imaging is typically estimated on a set of predefined regions of interest (ROIs) derived from an anatomical or static functional atlas which follows an implicit assumption of functional homogeneity within ROIs underlying temporal fluctuation of functional coupling, potentially leading to biases or underestimation of brain network dynamics. Here, we presented a novel computational method based on dynamic functional connectivity degree (dFCD) to derive meaningful brain parcellations that can capture functional homogeneous regions in temporal variance of functional connectivity. Several spatially distributed but functionally meaningful areas that are well consistent with known intrinsic connectivity networks were identified through independent component analysis (ICA) of time-varying dFCD maps. Furthermore, a systematical comparison with commonly used brain atlases, including the Anatomical Automatic Labeling template, static ICA-driven parcellation and random parcellation, demonstrated that the ROI-definition strategy based on the proposed dFC-driven parcellation could better capture the interindividual variability in dFC and predict observed individual cognitive performance (e.g., fluid intelligence, cognitive flexibility, and sustained attention) based on chronnectome. Together, our findings shed new light on the functional organization of resting brains at the timescale of seconds and emphasized the significance of a dFC-driven and voxel-wise functional homogeneous parcellation for network dynamics analyses in neuroscience.
到目前为止,基于功能磁共振成像的动态功能连接 (dFC) 通常是基于从解剖学或静态功能图谱中得出的一组预定义的感兴趣区域 (ROI) 进行估计的,这遵循了 ROI 内功能连接时间波动的功能同质性的隐含假设,可能导致大脑网络动态的偏差或低估。在这里,我们提出了一种基于动态功能连接度 (dFCD) 的新计算方法,以推导出有意义的脑区划分,从而可以捕获功能连接时变中的功能同质区域。通过时变 dFCD 图谱的独立成分分析 (ICA),可以识别出几个空间分布但功能上有意义的区域,这些区域与已知的内在连通性网络非常一致。此外,与常用的脑图谱(包括解剖自动标记模板、静态 ICA 驱动的分区和随机分区)进行了系统比较,表明基于所提出的 dFC 驱动的分区的 ROI 定义策略可以更好地捕捉 dFC 的个体间变异性,并基于 chronnectome 预测观察到的个体认知表现(例如,流体智力、认知灵活性和持续注意力)。总之,我们的发现为秒级静息大脑的功能组织提供了新的视角,并强调了基于 dFC 和体素的功能同质分区对于神经科学中网络动态分析的重要性。