The dynamic of the temporal correlations between brain areas, called functional connectivity (FC), undergoes complex transformations through the life span. In this review, we aim to provide an overview of these changes in the nonpathological brain from fetal life to advanced age. After a brief description of the main methods, we propose that FC development can be divided into four main phases: first, before birth, a strong change in FC leads to the emergence of functional proto‐networks, involving mainly within network short‐range connections. Then, during the first years of life, there is a strong widespread organization of networks which starts with segregation processes followed by a continuous increase in integration. Thereafter, from adolescence to early adulthood, a refinement of existing networks in the brain occurs, characterized by an increase in integrative processes until about 40 years. Middle age constitutes a pivotal period associated with an inversion of the functional brain trajectories with a decrease in segregation process in conjunction to a large‐scale reorganization of between network connections. Studies suggest that these processes are in line with the development of cognitive and sensory functions throughout life as well as their deterioration. During aging, results support the notion of dedifferentiation processes, which refer to the decrease in functional selectivity of the brain regions, resulting in more diffuse and less specialized FC, associated with the disruption of cognitive functions with age. The inversion of developmental processes during aging is in accordance with the developmental models of neuroanatomy for which the latest matured regions are the first to deteriorate.

中文翻译：

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人类一生中功能性大脑连接的变化：从胎儿发育到老年。

大脑区域之间的时间相关性的动态，称为功能连接 (FC)，在整个生命周期中经历复杂的转变。在这篇综述中，我们旨在概述从胎儿到高龄的非病理性大脑的这些变化。在对主要方法进行简要描述后，我们提出 FC 发展可以分为四个主要阶段：首先，在诞生之前，FC 的强烈变化导致功能原型网络的出现，主要涉及网络短程连接. 然后，在生命的最初几年，有一个强大的广泛的网络组织，从隔离过程开始，然后是不断增加的集成。此后，从青春期到成年早期，大脑中现有的网络会发生改进，其特点是综合过程的增加直到大约 40 年。中年是一个关键时期，与功能性大脑轨迹的反转相关，分离过程的减少以及网络连接之间的大规模重组。研究表明，这些过程与整个生命过程中认知和感觉功能的发展以及它们的退化是一致的。在衰老过程中，结果支持去分化过程的概念，这是指大脑区域功能选择性的降低，导致更多的扩散和更少的专业化 FC，与随着年龄的认知功能的破坏有关。