认知与发展心理学研究室知识库

白质作为连接神经元的重要组织，是大脑中神经信号的主要传导者，与个体的心理与行为发展有着密切关系。儿童青少年处于大脑可塑性发展的重要时期，体能水平已被广泛证实能够有效地优化大脑的灰质结构和功能发育，进而对个体的认知和行为产生积极的促进作用，但体能与大脑白质之间的关联研究尚为缺乏。此外，身体活动作为个体差异的重要因素，其在大脑白质发育过程中所起的潜在作用，也还未见报道。本研究基于“彩巢计划—成长在中国”儿童青少年数据库，采用弥散张量成像技术，系统考察 6-12 岁儿童体能水平与大脑白质发育之间的关联，深入探究其身体活动在二者关系中的关键性作用。

研究一对127名年龄在6至12岁之间的健康儿童，利用弥散张量成像 （Diffusion Tensor Imaging, DTI）技术和基于全脑图谱的分析方法，考察了他们大脑白质随年龄变化的特征。结果显示，随着年龄的增长，白质的各向异性分数（fractional anisotropy, FA）值呈现出显著的上升趋势，平均扩散率(mean diffusivity, MD)、轴向扩散率（axial diffusivity, AD）、径向扩散率（radial diffusivity, RD）则相应下降。这种年龄相关的发展轨迹在不同脑区之间表现出差异性。研究二根据中国学生标准化体质评估方案采集了有氧体适能、上肢力量和下肢力量三项体能指标数据，结果显示，体能指标与大脑多个脑区白质参数存在显著相关，其中与下肢力量相关的脑区分布最为广泛。有氧体适能与小脑上脚的 FA、MD、AD、 RD 均表现出显著的相关性；上肢、下肢力量分别与右侧皮质脊髓束 FA、RD 以及大脑脚 FA、MD、RD 呈显著相关。研究三采用《体育活动等级量表》评估儿童的身体活动量，通过调节效应分析发现，身体活动量作为体能与大脑白质之间的调节变量作用显著。

以上研究结果表明，6-12 岁儿童处于大脑可塑性的关键阶段，大脑白质随年龄增长呈现出快速发展的特点。体能作为影响个体差异的重要因素，与大脑白质发育之间存在显著的关联。身体活动量，作为一个可调控的外部环境因素，在体能与大脑白质之间起到调节作用，同样影响着大脑发育。这些研究结果一方面为身体活动影响儿童大脑白质发育提供了确凿的科学证据，另一方面对教育实践和政策制定具有现实的启示意义。

White matter, as the prime conductor of neural signaling within the brain, plays a crucial role in shaping human behavior. The developmental stages of childhood are particularly critical for brain plasticity. Countless studies have demonstrated that physical fitness effectively enhances the structural and functional development of the brain gray matter, thereby having positive effects on cognition and behavior. However, research on the relationship between physical fitness and white matter is still lacking. Furthermore, it has not been reported whether physical activity, as an important factor of individual variation, holds the potential role to influence the development of white matter in the brain. Based on the dataset from “Developmental Chinese Color Nest Project (devCCNP)” and leveraging diffusion tensor imaging technology, this study aims to systematically examine correlation between physical fitness and white matter development in children aged 6 to 12 years, and to explore the key role of physical activity in the relationship between the two.

Study 1 investigated the relationship between white matter and age with atlasbased diffusion tensor imaging (DTI) technology, for 127 healthy children between 6 to 12 years old. The results revealed that as age increased, the fractional anisotropy (FA) value significantly increased, whereas mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD) decreased. Notably, this age-related growth curves exhibited variations across different brain white matter regions. The second study explored the relationship between physical fitness of children, including cardiorespiratory fitness, upper extremity strength and lower extremity strength, and the development of white matter in the brain. The findings showed that significant correlations between these fitness parameters and DTI parameters across multiple brain regions. Notably, lower extremity strength demonstrated the most widespread correlation. For instance, the cardiorespiratory fitness was significantly correlated with FA, MD, AD and RD in the superior cerebellar peduncles; a significantly correlation was observed between the upper extremity strength and FA and RD in the right corticospinal tract; in the cerebral This study further examined the correlation between the level of physical activity and the white matter DTI parameters, and the results revealed that physical activity played a significant role as a moderating variable between physical fitness and white matter development.

The findings presented above demonstrated that children aged 6 to 12 years are in the critical phase of brain plasticity, wherein white matter underwent a pronounced developmental surge with age. Physical fitness, a pivotal determinant of individual variability, exhibited a significant correlation with white matter development. Furthermore, physical activity, a modifiable external environmental factor, served a moderating role between physical fitness and white matter development, thereby influencing brain plasticity as well. These compelling outcomes provide strong scientific evidence for the pivotal role of physical activity in fostering the white matter development in children, and bear profound practical implications for physical education and policy formulation.