Department of Electrical Engineering, Indian Institute of Technology, Delhi, New Delhi, 110016, India.
Department of Electronics and Communication Engineering, Indraprastha Institute of Information Technology, New Delhi, 110020, India.
Sci Rep. 2021 Feb 2;11(1):2822. doi: 10.1038/s41598-021-81884-3.
Time-varying neurophysiological activity has been classically explored using correlation based sliding window analysis. However, this method employs only lower order statistics to track dynamic functional connectivity of the brain. We introduce recursive dynamic functional connectivity (rdFC) that incorporates higher order statistics to generate a multi-order connectivity pattern by analyzing neurophysiological data at multiple time scales. The technique builds a hierarchical graph between various temporal scales as opposed to traditional approaches that analyze each scale independently. We examined more than a million rdFC patterns obtained from morphologically diverse EEGs of 2378 subjects of varied age and neurological health. Spatiotemporal evaluation of these patterns revealed three dominant connectivity patterns that represent a universal underlying correlation structure seen across subjects and scalp locations. The three patterns are both mathematically equivalent and observed with equal prevalence in the data. The patterns were observed across a range of distances on the scalp indicating that they represent a spatially scale-invariant correlation structure. Moreover, the number of patterns representing the correlation structure has been shown to be linked with the number of nodes used to generate them. We also show evidence that temporal changes in the rdFC patterns are linked with seizure dynamics.
时变神经生理活动一直以来都采用基于相关的滑动窗口分析方法进行探索。然而，这种方法仅使用较低阶的统计信息来跟踪大脑的动态功能连接。我们引入了递归动态功能连接（rdFC），它通过在多个时间尺度上分析神经生理数据，结合了更高阶的统计信息，从而生成多阶连接模式。该技术在各个时间尺度之间构建了一个层次图，而不是传统方法那样独立地分析每个尺度。我们检查了来自 2378 名不同年龄和神经健康状况的受试者形态多样的 EEG 中获得的超过 100 万个 rdFC 模式。对这些模式的时空评估揭示了三种主要的连接模式，它们代表了跨受试者和头皮位置的普遍存在的潜在相关结构。这三种模式在数学上是等效的，并且在数据中以相同的频率观察到。这些模式在头皮上的不同距离上都有观察到，这表明它们代表了一种空间尺度不变的相关结构。此外，代表相关结构的模式数量与用于生成它们的节点数量有关。我们还提供了证据表明，rdFC 模式的时间变化与癫痫发作动力学有关。
