Uncovering the moment-to-moment dynamics of functional connectivity (FC) in the human brain during early development is crucial for understanding emerging complex cognitive functions and behaviors. To this end, this paper leveraged a longitudinal resting-state functional magnetic resonance imaging dataset from 51 typically developing infants and, for the first time, thoroughly investigated how the temporal variability of the FC architecture develops at the “global” (entire brain), “mesoscale” (functional system), and “local” (brain region) levels in the first 2 years of age. Our results revealed that, in such a pivotal stage, 1) the whole-brain FC dynamic is linearly increased; 2) the high-order functional systems tend to display increased FC dynamics for both within- and between-network connections, while the primary systems show the opposite trajectories; and 3) many frontal regions have increasing FC dynamics despite large heterogeneity in developmental trajectories and velocities. All these findings indicate that the brain is gradually reconfigured toward a more flexible, dynamic, and adaptive system with globally increasing but locally heterogeneous trajectories in the first 2 postnatal years, explaining why infants have rapidly developing high-order cognitive functions and complex behaviors.

中文翻译：

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婴儿早期动态功能架构的开发。

揭示人类大脑早期发育过程中功能连接 (FC) 的即时动态对于理解新兴的复杂认知功能和行为至关重要。为此，本文利用来自 51 个典型发育婴儿的纵向静息状态功能磁共振成像数据集，并首次彻底研究了 FC 架构的时间可变性如何在“全球”（整个大脑）发展，前 2 岁的“中尺度”（功能系统）和“局部”（大脑区域）水平。我们的结果表明，在这样一个关键阶段，1）全脑 FC 动态线性增加；2) 高阶功能系统倾向于显示网络内和网络间连接的 FC 动态增加，而主要系统显示出相反的轨迹；3）尽管发展轨迹和速度存在很大的异质性，但许多正面区域的 FC 动态不断增加。所有这些发现表明，在出生后的前 2 年，大脑逐渐被重新配置为更灵活、动态和适应性更强的系统，具有全球增加但局部异质的轨迹，这解释了为什么婴儿快速发展高阶认知功能和复杂行为。