Vakorin Vasily A, Liaqat Hayyan, Doesburg Sam M, Moreno Sylvain
Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
Royal Columbian Hospital, Fraser Health Authority, New Westminster, BC, Canada.
Front Aging Neurosci. 2025 Mar 4;17:1498400. doi: 10.3389/fnagi.2025.1498400. eCollection 2025.
Neurophysiological activity, as noninvasively captured by electro- and magnetoencephalography (EEG and MEG), demonstrates complex temporal fluctuations approximated by typical variations around the mean values and rare events with large amplitude. The statistical properties of these extreme and rare events in neurodynamics may reflect the limits or capacity of the brain as a complex system in information processing. However, the exact role of these extreme neurodynamic events in ageing, and their spectral and spatial patterns remain elusive. Our study hypothesized that ageing would be associated with frequency specific alterations in the brain's tendency to synchronize large ensembles of neurons and to produce extreme events.
To identify spatio-spectral patterns of these age-related changes in extreme neurodynamics, we examined resting-state MEG recordings from a large cohort of adults ( = 645), aged 18 to 89. We characterized extreme neurodynamics by computing sample skewness and kurtosis, and used Partial Least Squares to test for differences across age groups.
Our findings revealed that each canonical frequency, from theta to lower gamma, displayed unique spatial patterns of either age-related increases, decreases, or both in the brain's tendency to produce extreme neuromagnetic events.
Our study introduces a novel neuroimaging framework for understanding ageing through the extreme and rare events of the neurophysiological activity, offering more sensitivity than typical comparative approaches.
脑电图（EEG）和脑磁图（MEG）以非侵入性方式捕捉到的神经生理活动，呈现出复杂的时间波动，其近似于围绕平均值的典型变化以及具有大幅值的罕见事件。神经动力学中这些极端和罕见事件的统计特性可能反映了大脑作为一个复杂系统在信息处理方面的极限或能力。然而，这些极端神经动力学事件在衰老过程中的确切作用及其频谱和空间模式仍然难以捉摸。我们的研究假设，衰老与大脑同步大量神经元集合并产生极端事件的倾向在频率特异性方面的改变有关。
为了识别这些与年龄相关的极端神经动力学变化的时空频谱模式，我们检查了一大群年龄在18至89岁之间的成年人（n = 645）的静息态MEG记录。我们通过计算样本偏度和峰度来表征极端神经动力学，并使用偏最小二乘法来检验不同年龄组之间的差异。
我们的研究结果表明，从θ波到低频γ波的每个标准频率，在大脑产生极端神经磁事件的倾向方面，都呈现出与年龄相关的增加、减少或两者兼具的独特空间模式。
我们的研究引入了一个新的神经影像学框架，通过神经生理活动的极端和罕见事件来理解衰老，比典型的比较方法具有更高的灵敏度。
