Effects of Neural Synchrony on Surface EEG
Effects of Neural Synchrony on Surface EEG
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DOI：
10.1093/cercor/bhs389
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发表时间：
2014-04-01
期刊：
影响因子：
3.7
通讯作者：
Whittingstall, Kevin
中科院分区：
文献类型：
--
作者：
Musall, Simon;von Pfoestl, Veronika;Whittingstall, Kevin
长期以来，人们一直认为表面脑电图（EEG）信号取决于潜在神经活动的幅度和空间同步，尽管分离它们各自的贡献仍然难以实现。为了解决这个问题，我们同时进行表面脑电图测量沿着与皮质内记录的局部场电位（LFPs）在初级视觉皮层的行为非人类灵长类动物。我们发现，试验的EEG功率波动可以解释的线性组合LFP功率和电极间的时间同步。在刺激和无刺激条件下都观察到这种效果，并且在伽马范围（30 - 100 Hz）中特别强。随后，我们使用药理学操作表明，即使LFP信号被负调制，神经同步也可以产生正调制的EEG信号。总之，我们的研究结果表明，神经同步可以调制脑电信号的幅度变化的神经活动独立。这一发现对基础和临床研究中EEG的解释具有很强的意义，并有助于协调在不同模态中观察到的EEG反应差异（例如，EEG与功能磁共振成像）和不同的空间尺度（例如，EEG与颅内EEG）。
It has long been assumed that the surface electroencephalography (EEG) signal depends on both the amplitude and spatial synchronization of underlying neural activity, though isolating their respective contribution remains elusive. To address this, we made simultaneous surface EEG measurements along with intracortical recordings of local field potentials (LFPs) in the primary visual cortex of behaving nonhuman primates. We found that trial-by-trial fluctuations in EEG power could be explained by a linear combination of LFP power and interelectrode temporal synchrony. This effect was observed in both stimulus and stimulus-free conditions and was particularly strong in the gamma range (30100 Hz). Subsequently, we used pharmacological manipulations to show that neural synchrony can produce a positively modulated EEG signal even when the LFP signal is negatively modulated. Taken together, our results demonstrate that neural synchrony can modulate EEG signals independently of amplitude changes in neural activity. This finding has strong implications for the interpretation of EEG in basic and clinical research, and helps reconcile EEG response discrepancies observed in different modalities (e.g., EEG vs. functional magnetic resonance imaging) and different spatial scales (e.g., EEG vs. intracranial EEG).