模块化动态图论度量有效地捕获了人脑发育过程中动态信息交互的模式。虽然现有的研究已经采用模块化算法来检查整个开发过程中社区结构动态变化的整体影响,在理解儿童早期不同功能网络中的跨社区动态变化及其对脑信息传递效率的潜在贡献方面存在显著差距.本研究旨在通过追踪幼儿功能网络中跨社区结构变化的轨迹并建模其对信息传输效率的贡献来解决这一差距。我们分析了83名2至8岁儿童的194次功能成像扫描,谁参加了被动观看功能磁共振成像会议。利用滑动窗口和模块化算法,我们评估了三个时空指标——时间灵活性,时空多样性,和社区内时空多样性-和四个中心性度量:社区内程度中心性,特征向量中心性,社区之间的程度中心性,和群落间特征向量中心性。混合效应线性模型揭示了默认模式网络(DMN)的时间灵活性与年龄相关的显著增加,执行控制网络(ECN),和显著性网络(SN),表明在幼儿期,这些网络中的社区结构经常调整。此外,SN的时空多样性也显示出与年龄相关的显着增长,突出了其广泛的跨社区动态互动模式。相反,语言网络中的社区内时空多样性表现出与年龄相关的显着下降,反映了网络逐渐的功能专业化。此外,我们的研究结果表明,在整个DMN中,与年龄相关的社区之间的中心性显著增加,ECN,SN,语言网络,和背侧注意力网络,虽然DMN的群落间特征向量中心性也显著增加,ECN,和SN。然而,在幼儿期,社区内特征向量中心性在所有功能网络中保持稳定。这些结果表明,虽然儿童早期功能网络中跨社区互动的中心性增加,社区内的中心地位保持稳定。最后,进行了调解分析,以探讨年龄之间的关系,大脑动态图指标,以及基于社区结构的全球和地方效率。结果表明,SN的动态图指标主要介导了年龄与全球效率下降之间的关系,而那些DMN的,语言网络,ECN,背侧注意网络,SN主要介导了年龄与局部效率提高之间的关系。这种模式表明了幼儿从全球信息整合到本地信息隔离的发展轨迹,SN在这一转变中起着举足轻重的作用。这项研究为儿童早期大脑功能发育通过功能网络中的跨社区调整影响信息传递效率的机制提供了新的见解。
Modular dynamic graph theory metrics effectively capture the patterns of dynamic information interaction during human brain development. While existing research has employed modular algorithms to examine the overall impact of dynamic changes in community structure throughout development, there is a notable gap in understanding the cross-community dynamic changes within different functional networks during early childhood and their potential contributions to the efficiency of brain information transmission. This study seeks to address this gap by tracing the trajectories of cross-community structural changes within early childhood functional networks and modeling their contributions to information transmission efficiency. We analyzed 194 functional imaging scans from 83 children aged 2 to 8 years, who participated in passive viewing functional magnetic resonance imaging sessions. Utilizing sliding windows and modular algorithms, we evaluated three spatiotemporal metrics-temporal flexibility, spatiotemporal diversity, and within-community spatiotemporal diversity-and four centrality metrics: within-community degree centrality, eigenvector centrality, between-community degree centrality, and between-community eigenvector centrality. Mixed-effects linear models revealed significant age-related increases in the temporal flexibility of the default mode network (DMN), executive control network (ECN), and salience network (SN), indicating frequent adjustments in community structure within these networks during early childhood. Additionally, the spatiotemporal diversity of the SN also displayed significant age-related increases, highlighting its broad pattern of cross-community dynamic interactions. Conversely, within-community spatiotemporal diversity in the language network exhibited significant age-related decreases, reflecting the network\'s gradual functional specialization. Furthermore, our findings indicated significant age-related increases in between-community degree centrality across the DMN, ECN, SN, language network, and dorsal attention network, while between-community eigenvector centrality also increased significantly for the DMN, ECN, and SN. However, within-community eigenvector centrality remained stable across all functional networks during early childhood. These results suggest that while centrality of cross-community interactions in early childhood functional networks increases, centrality within communities remains stable. Finally, mediation analysis was conducted to explore the relationships between age, brain dynamic graph metrics, and both global and local efficiency based on community structure. The results indicated that the dynamic graph metrics of the SN primarily mediated the relationship between age and the decrease in global efficiency, while those of the DMN, language network, ECN, dorsal attention network, and SN primarily mediated the relationship between age and the increase in local efficiency. This pattern suggests a developmental trajectory in early childhood from global information integration to local information segregation, with the SN playing a pivotal role in this transformation. This study provides novel insights into the mechanisms by which early childhood brain functional development impacts information transmission efficiency through cross-community adjustments in functional networks.