Reliable local dynamics in the brain across sessions are revealed by whole-brain modeling of resting state activity
Reliable local dynamics in the brain across sessions are revealed by whole-brain modeling of resting state activity
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DOI：
10.1002/hbm.24572
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发表时间：
2019-07-01
影响因子：
4.8
通讯作者：
Deco, Gustavo
中科院分区：
文献类型：
--
作者：
Donnelly-Kehoe, Patricio;Saenger, Victor M.;Deco, Gustavo
静息态功能磁共振成像是研究人脑功能组织的工具。 “休息”时正在进行的大脑活动是高度动态的，但相关或独立成分分析等程序将功能连接 (FC) 视为理论上是静止的，因此在 FC 中观察到的波动被认为是噪声。因此，FC 通常不用作单受试者水平标记，并且仅限于小组研究。在这里，我们开发了一种基于成像的技术，能够通过使用持续动态的全脑模型来可靠地描绘单个受试者水平的局部动态信息，该模型估计局部参数，该参数反映每个大脑区域是否呈现稳定、异步或短暂的振荡。使用一个受试者的 50 次纵向静息态会话和一组 50 名参与者的单次静息态会话，我们证明，使用 20 分钟的扫描时间，可以与群体动态一致地量化大脑动态。我们表明，大脑中枢更接近同步和异步振荡动力学之间的过渡点，并且与其他小叶相比，额叶区域的动力学值具有更大的异质性。然而，同一受试者的额叶区域和中枢表现出较高的一致性，而主要视觉和运动区域的会话间变异性仅与受试者之间的变异性一样高。这里提出的框架可用于研究群体的功能性大脑动力学，更重要的是，在个体水平上，为可能的临床应用开辟新的途径。
Resting state fMRI is a tool for studying the functional organization of the human brain. Ongoing brain activity at "rest" is highly dynamic, but procedures such as correlation or independent component analysis treat functional connectivity (FC) as if, theoretically, it is stationary and therefore the fluctuations observed in FC are thought as noise. Consequently, FC is not usually used as a single-subject level marker and it is limited to group studies. Here we develop an imaging-based technique capable of reliably portraying information of local dynamics at a single-subject level by using a whole-brain model of ongoing dynamics that estimates a local parameter, which reflects if each brain region presents stable, asynchronous or transitory oscillations. Using 50 longitudinal resting-state sessions of one single subject and single resting-state sessions from a group of 50 participants we demonstrate that brain dynamics can be quantified consistently with respect to group dynamics using a scanning time of 20 min. We show that brain hubs are closer to a transition point between synchronous and asynchronous oscillatory dynamics and that dynamics in frontal areas have larger heterogeneity in its values compared to other lobules. Nevertheless, frontal regions and hubs showed higher consistency within the same subject while the inter-session variability found in primary visual and motor areas was only as high as the one found across subjects. The framework presented here can be used to study functional brain dynamics at group and, more importantly, at individual level, opening new avenues for possible clinical applications.