Imaging the spontaneous flow of thought: Distinct periods of cognition contribute to dynamic functional connectivity during rest
Imaging the spontaneous flow of thought: Distinct periods of cognition contribute to dynamic functional connectivity during rest
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DOI：
10.1016/j.neuroimage.2019.116129
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发表时间：
2019-11-15
期刊：
影响因子：
5.7
通讯作者：
Bandettini, Peter A.
中科院分区：
文献类型：
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作者：
Gonzalez-Castillo, Javier;Caballero-Gaudes, Cesar;Bandettini, Peter A.
使用功能磁共振成像技术可以在几秒钟内测量大脑功能连接（FC）的变化。对于休息和任务场景都是如此。此外，人们普遍认为任务参与会改变 FC，并且在任务事件期间和之前对 FC 的动态估计可以帮助预测其性质和绩效。然而，当谈到休息期间的动态 FC (dFC) 时，对其起源或意义尚未达成共识。一些人认为，休息 dFC 反映了持续认知的波动，或者是大脑内在维持机制的表现，这可能具有预测临床价值。相反，其他人得出的结论是，静息 dFC 主要是采样变异性、头部运动或睡眠状态波动的结果。在这里，我们提出新颖的分析，表明休息 dFC 受到短期自发认知任务样过程的影响，并且这种心理过程的认知本质可以从数据中盲目推断。因此，即使受试者持续清醒并表现出最小的运动，在单次休息扫描期间也可能会出现几种不同的行为相关的全脑 FC 配置。此外，使用低维嵌入作为可视化辅助，我们展示了 FC 状态（通常用于总结和解释静息 dFC）如何能够准确而稳健地揭示外部施加的任务的周期；然而，它们在捕捉休息期间的不同认知时段方面可能不太有效。
Brain functional connectivity (FC) changes have been measured across seconds using fMRI. This is true for both rest and task scenarios. Moreover, it is well accepted that task engagement alters FC, and that dynamic estimates of FC during and before task events can help predict their nature and performance. Yet, when it comes to dynamic FC (dFC) during rest, there is no consensus about its origin or significance. Some argue that rest dFC reflects fluctuations in on-going cognition, or is a manifestation of intrinsic brain maintenance mechanisms, which could have predictive clinical value. Conversely, others have concluded that rest dFC is mostly the result of sampling variability, head motion or fluctuating sleep states. Here, we present novel analyses suggesting that rest dFC is influenced by short periods of spontaneous cognitive-task-like processes, and that the cognitive nature of such mental processes can be inferred blindly from the data. As such, several different behaviorally relevant whole-brain FC configurations may occur during a single rest scan even when subjects were continuously awake and displayed minimal motion. In addition, using low dimensional embeddings as visualization aids, we show how FC states-commonly used to summarize and interpret resting dFC-can accurately and robustly reveal periods of externally imposed tasks; however, they may be less effective in capturing periods of distinct cognition during rest.