Coupling of neuronal oscillations may reflect and facilitate the communication between neuronal populations. Two primary neuronal coupling modes have been described: phase-coupling and amplitude-coupling. Theoretically, both coupling modes are independent, but so far, their neuronal relationship remains unclear. Here, we combined MEG, source-reconstruction and simulations to systematically compare cortical amplitude-coupling and phase-coupling patterns in the human brain. Importantly, we took into account a critical bias of amplitude-coupling measures due to phase-coupling. We found differences between both coupling modes across a broad frequency range and most of the cortex. Furthermore, by combining empirical measurements and simulations we ruled out that these results were caused by methodological biases, but instead reflected genuine neuronal amplitude coupling. Our results show that cortical phase- and amplitude-coupling patterns are non-redundant, which may reflect at least partly distinct neuronal mechanisms. Furthermore, our findings highlight and clarify the compound nature of amplitude coupling measures.

中文翻译：

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人脑中分离的神经元相位和幅度耦合模式

神经元振荡的耦合可以反映和促进神经元群之间的交流。已经描述了两种主要的神经元耦合模式：相位耦合和幅度耦合。理论上，两种耦合模式都是独立的，但到目前为止，它们的神经元关系仍不清楚。在这里，我们结合 MEG、源重建和模拟来系统地比较人脑中的皮质幅度耦合和相位耦合模式。重要的是，我们考虑了由于相位耦合引起的幅度耦合测量的临界偏差。我们发现两种耦合模式在广泛的频率范围和大部分皮层之间存在差异。此外，通过结合经验测量和模拟，我们排除了这些结果是由方法偏差引起的，而是反映了真正的神经元振幅耦合。我们的结果表明，皮质相位和幅度耦合模式是非冗余的，这可能至少部分反映了不同的神经元机制。此外，我们的发现突出并阐明了幅度耦合测量的复合性质。