Avalanche dynamics of human brain oscillations: Relation to critical branching processes and temporal correlations
Avalanche dynamics of human brain oscillations: Relation to critical branching processes and temporal correlations
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DOI：
10.1002/hbm.20590
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发表时间：
2008-07-01
影响因子：
4.8
通讯作者：
Linkenkaer-Hansen, Klaus
中科院分区：
文献类型：
--
作者：
Poil, Simon-Shlomo;van Ooyen, Arjen;Linkenkaer-Hansen, Klaus
人脑振荡在休息期间的振幅波动不规则，并表现出时间相关性的幂律衰减。有人认为，这种动力学反映了临界状态附近的自组织活动。在这个框架下，振荡爆发可以解释为神经元雪崩传播的网络中的一个临界分支比。然而，一个直接的比较的时间结构的持续振荡与活动传播的模型网络中的关键连接从来没有。在这里，我们模拟分支过程和雪崩寿命分布和时间相关性方面的活动传播的特点。介绍了一种等效分析，用于表征休息期间脑磁图（MEG）记录的α-频带中正在进行的振荡。我们发现，模型的分支比接近临界值的一个表现出幂律标度的寿命分布与相似的标度指数中观察到的MEG数据。该模型再现定性的幂律衰减的时间相关性在人类的数据，但是，在模型中的相关性出现在时间尺度上，只有最长的雪崩，而人类的数据表明持久性的相关性的时间尺度上对应的几个突发事件。我们的研究结果支持的想法，神经网络产生持续的α振荡在休息期间操作的临界状态附近，但也表明，不包括在简单的经典分支过程中的因素需要考虑到复杂的时间结构的持续振荡在休息的时间尺度上长于持续时间的个人振荡爆发。
Human brain oscillations fluctuate erratically in amplitude during rest and exhibit power-law decay of temporal correlations. It has been suggested that this dynamics reflects self-organized activity near a critical state. In this framework, oscillation bursts may be interpreted as neuronal avalanches propagating in a network with a critical branching ratio. However, a direct comparison of the temporal structure of ongoing oscillations with that of activity propagation in a model network with critical connectivity has never been made. Here, we simulate branching processes and characterize the activity propagation in terms of avalanche life-time distributions and temporal correlations. An equivalent analysis is introduced for characterizing ongoing oscillations in the alpha-frequency band recorded with magnetoencephalography (MEG) during rest. We found that models with a branching ratio near the critical value of one exhibited power-law scaling in life-time distributions with similar scaling exponents as observed in the MEG data. The models reproduced qualitatively the power-law decay of temporal correlations in the human data; however, the correlations in the model appeared on time scales only up to the longest avalanche, whereas human data indicate persistence of correlations on time scales corresponding to several burst events. Our results support the idea that neuronal networks generating ongoing alpha oscillations during rest operate near a critical state, but also suggest that factors not included in the simple classical branching process are needed to account for the complex temporal structure of ongoing oscillations during rest on time scales longer than the duration of individual oscillation bursts.