State Key Laboratory of Cognitive Neuroscience and Learning, International Data Group/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China.
Department of Psychology, Yale University, New Haven, CT 06511.
Proc Natl Acad Sci U S A. 2021 Jul 13;118(28). doi: 10.1073/pnas.2024448118. Epub 2021 Jul 6.
The transition from childhood to adolescence is marked by pronounced shifts in brain structure and function that coincide with the development of physical, cognitive, and social abilities. Prior work in adult populations has characterized the topographical organization of the cortex, revealing macroscale functional gradients that extend from unimodal (somatosensory/motor and visual) regions through the cortical association areas that underpin complex cognition in humans. However, the presence of these core functional gradients across development as well as their maturational course have yet to be established. Here, leveraging 378 resting-state functional MRI scans from 190 healthy individuals aged 6 to 17 y old, we demonstrate that the transition from childhood to adolescence is reflected in the gradual maturation of gradient patterns across the cortical sheet. In children, the overarching organizational gradient is anchored within the unimodal cortex, between somatosensory/motor and visual territories. Conversely, in adolescence, the principal gradient of connectivity transitions into an adult-like spatial framework, with the default network at the opposite end of a spectrum from primary sensory and motor regions. The observed gradient transitions are gradually refined with age, reaching a sharp inflection point in 13 and 14 y olds. Functional maturation was nonuniformly distributed across cortical networks. Unimodal networks reached their mature positions early in development, while association regions, in particular the medial prefrontal cortex, reached a later peak during adolescence. These data reveal age-dependent changes in the macroscale organization of the cortex and suggest the scheduled maturation of functional gradient patterns may be critically important for understanding how cognitive and behavioral capabilities are refined across development.
从儿童期到青春期的转变伴随着大脑结构和功能的显著变化，这些变化与身体、认知和社会能力的发展相吻合。先前在成年人群中的研究已经描述了大脑皮层的拓扑组织，揭示了从单一模态（感觉运动和视觉）区域延伸到支持人类复杂认知的皮层联合区域的宏观功能梯度。然而，这些核心功能梯度在整个发育过程中的存在及其成熟过程尚未确定。在这里，我们利用来自 190 名年龄在 6 至 17 岁之间的健康个体的 378 个静息态功能磁共振成像扫描，证明了从儿童期到青春期的转变反映在皮层薄片上梯度模式的逐渐成熟。在儿童中，总的组织梯度锚定在单一模态皮层内，在感觉运动和视觉区域之间。相反，在青春期，连接的主要梯度转变为成人样的空间框架，默认网络位于主要感觉和运动区域的相反端。观察到的梯度转变随着年龄的增长逐渐得到改善，在 13 岁和 14 岁时达到一个明显的转折点。功能成熟在皮层网络中分布不均匀。单一模态网络在发育早期就达到了成熟的位置，而联合区域，特别是内侧前额叶皮层，在青春期达到了较晚的高峰。这些数据揭示了大脑皮层宏观组织的年龄依赖性变化，并表明功能梯度模式的预定成熟对于理解认知和行为能力如何在整个发育过程中得到改善可能至关重要。
