Brain Korea 21 Project for Medical Science, Department of Radiology, Nuclear Medicine and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
Neuroimage. 2012 Jan 2;59(1):456-66. doi: 10.1016/j.neuroimage.2011.07.049. Epub 2011 Jul 23.
Despite the widespread view of the brain as a large complex network, the dynamicity of the brain network over the course of a day has yet to be explored. To investigate whether the spontaneous human brain network maintains long-term stability throughout a day, we evaluated the intra-class correlation coefficient (ICC) of results from an independent component analysis (ICA), seed correlation analysis, and graph-theoretical analysis of resting state functional MRI, acquired from 12 young adults at three-hour intervals over 24 consecutive hours. According to the ICC of the usage strength of the independent network component defined by the root mean square of the temporal weights of the network components, the default mode network centered at the posterior cingulate cortex and precuneus, the superior parietal, and secondary motor networks showed a high temporal stability throughout the day (ICC>0.5). However, high intra-individual dynamicity was observed in the default mode network, including the anterior cingulate cortex and medial prefrontal cortex or posterior-anterior cingulate cortex, the hippocampal network, and the parietal and temporal networks. Seed correlation analysis showed a highly stable (ICC>0.5) extent of functionally connected regions from the posterior cingulate cortex, but poor stability from the hippocampus throughout the day. Graph-theoretical analysis using local and global network efficiency suggested that local brain networks are temporally stable but that long-range integration behaves dynamically in the course of a day. These results imply that dynamic network properties are a nature of the resting state brain network, which remains to be further researched.
尽管大脑被广泛认为是一个大型复杂网络，但大脑网络在一天中的动态变化尚未得到探索。为了研究人类大脑网络在一天中是否保持长期稳定，我们评估了静息态功能磁共振成像中独立成分分析（ICA）、种子相关分析和图论分析结果的组内相关系数（ICC），这些结果来自 12 名年轻成年人在 24 小时内每三小时采集一次。根据网络成分时间权重均方根定义的独立网络成分使用强度的 ICC，以后扣带回皮质和楔前叶为中心的默认模式网络、上顶叶和次要运动网络在一天中表现出较高的时间稳定性（ICC>0.5）。然而，默认模式网络中的个体内动态性较高，包括前扣带回皮质和内侧前额叶或后扣带回皮质、海马网络以及顶叶和颞叶网络。种子相关分析显示，从后扣带回皮质到功能连接区域的高度稳定（ICC>0.5），但全天从海马体到功能连接区域的稳定性较差。使用局部和全局网络效率的图论分析表明，局部脑网络具有时间稳定性，但在一天的过程中长程整合表现出动态性。这些结果表明，动态网络特性是静息态大脑网络的固有特性，有待进一步研究。
