Neşe Hüden, Harı Emre, Ay Ulaş, Demiralp Tamer, Ademoğlu Ahmet
Institute of Biomedical Engineering, Boğaziçi University, 34684, Istanbul, Turkey.
Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, 34093, Istanbul, Turkey.
Brain Struct Funct. 2024 Dec;229(9):2405-2417. doi: 10.1007/s00429-024-02847-8. Epub 2024 Aug 19.
Despite converging evidence of hierarchical organization in the cerebral cortex, with sensory-motor and association regions at opposite ends, the mechanism of such hierarchical interactions remains elusive. This organization was primarily investigated regarding the spatiotemporal dynamics of intrinsic connectivity networks (ICNs). However, more effort is needed to investigate network dynamics in the frequency domain. We aimed to examine the integrative role of brain regions in the frequency domain with graph metrics. Phase-based connectivity estimation was performed in three frequency bands (0.011-0.038, 0.043-0.071, and 0.076-0.103 Hz) in the BOLD signal during rest. We applied modularity analysis to connectivity matrices and investigated those areas, which we called integrative regions, that showed frequency-domain flexibility. Integrative regions, mostly belonging to attention networks, were densely connected to higher-order cognitive ICNs in lower frequency bands but to sensory-motor ICNs in higher frequency bands. We compared the normalized participation coefficient (P) values of integrative and core regions with respect to their relation to higher-order cognition using a permutation-based t-test for multiple linear regression. Regression parameters of integrative regions in relation to three cognitive scores in executive functions, and working memory were significantly larger than those of core regions (P < 0.05) for salience ventral attention network. Parameters of integrative regions in relation to intelligence scores were significantly larger than those with core regions (P < 0.05) in dorsal attention network. Larger parameters of neuropsychological test scores in relation to these flexible parcels further indicate their essential role at an intermediate level in behavior. Results emphasize the importance of frequency-band analysis of brain networks.
尽管有越来越多的证据表明大脑皮层存在层次组织，感觉运动区和联合区位于两端，但这种层次交互的机制仍然难以捉摸。这种组织主要是关于内在连接网络（ICN）的时空动态进行研究的。然而，在频域中研究网络动态还需要更多的努力。我们旨在用图论指标来研究大脑区域在频域中的整合作用。在静息状态下，对BOLD信号的三个频段（0.011 - 0.038、0.043 - 0.071和0.076 - 0.103赫兹）进行基于相位的连接性估计。我们对连接矩阵应用模块化分析，并研究那些表现出频域灵活性的区域，我们称之为整合区域。整合区域大多属于注意力网络，在较低频段与高阶认知ICN紧密相连，而在较高频段与感觉运动ICN紧密相连。我们使用基于排列的多元线性回归t检验，比较了整合区域和核心区域相对于它们与高阶认知的关系的标准化参与系数（P）值。对于显著腹侧注意力网络，整合区域与执行功能和工作记忆中的三个认知分数相关的回归参数显著大于核心区域（P < 0.05）。在背侧注意力网络中，整合区域与智力分数相关的参数显著大于核心区域（P < 0.05）。与这些灵活脑区相关的神经心理测试分数的更大参数进一步表明它们在行为的中间水平上的重要作用。结果强调了大脑网络频带分析的重要性。
