Abraham Ivan, Shahsavarani Somayeh, Zimmerman Benjamin, Husain Fatima T, Baryshnikov Yuliy
Coordinated Science Laboratory, University of Illinois, Urbana-Champaign, Urbana, USA.
Department of Audiology, San Jose State University, San Jose, USA.
Netw Neurosci. 2024 Dec 10;8(4):1105-1128. doi: 10.1162/netn_a_00392. eCollection 2024.
A fine-grained understanding of dynamics in cortical networks is crucial to unpacking brain function. Resting-state functional magnetic resonance imaging (fMRI) gives rise to time series recordings of the activity of different brain regions, which are aperiodic and lack a base frequency. Cyclicity analysis, a novel technique robust under time reparametrizations, is effective in recovering the temporal ordering of such time series, collectively considered components of a multidimensional trajectory. Here, we extend this analytical method for characterizing the dynamic interaction between distant brain regions and apply it to the data from the Human Connectome Project. Our analysis detected cortical traveling waves of activity propagating along a spatial axis, resembling cortical hierarchical organization with consistent lead-lag relationships between specific brain regions in resting-state scans. In fMRI scans involving tasks, we observed short bursts of task-modulated strong temporal ordering that dominate overall lead-lag relationships between pairs of regions in the brain that align temporally with stimuli from the tasks. Our results suggest a possible role played by waves of excitation sweeping through brain regions that underlie emergent cognitive functions.
对皮质网络动力学有细致入微的理解对于揭示脑功能至关重要。静息态功能磁共振成像（fMRI）产生了不同脑区活动的时间序列记录，这些记录是非周期性的且缺乏基频。循环分析是一种在时间重新参数化下稳健的新技术，能有效地恢复此类时间序列的时间顺序，这些时间序列被共同视为多维轨迹的组成部分。在这里，我们扩展了这种用于表征远距离脑区之间动态相互作用的分析方法，并将其应用于人类连接组计划的数据。我们的分析检测到了沿空间轴传播的皮质活动行波，类似于皮质层次组织，在静息态扫描中特定脑区之间具有一致的领先 - 滞后关系。在涉及任务的fMRI扫描中，我们观察到任务调制的强时间顺序的短脉冲，这些脉冲主导了大脑中在时间上与任务刺激对齐的区域对之间的整体领先 - 滞后关系。我们的结果表明，兴奋波席卷脑区可能在新兴认知功能的基础中发挥作用。
