Oscillatory neural activities are prevalent in the brain with their phase realignment contributing to the coordination of neural communication. Phase realignments may have especially strong (or weak) impact when neural activities are strongly synchronized (or desynchronized) within the interacting populations. We report that the spatiotemporal dynamics of strong regional synchronization measured as maximal EEG spectral power--referred to as activation--and strong regional desynchronization measured as minimal EEG spectral power--referred to as suppression--are characterized by the spatial segregation of small-scale and large-scale networks. Specifically, small-scale spectral-power activations and suppressions involving only 2-7% (1-4 of 60) of EEG scalp sites were prolonged (relative to stochastic dynamics) and consistently co-localized in a frequency specific manner. For example, the small-scale networks for θ, α, β1, and β2 bands (4-30 Hz) consistently included frontal sites when the eyes were closed, whereas the small-scale network for γ band (31-55 Hz) consistently clustered in medial-central-posterior sites whether the eyes were open or closed. Large-scale activations and suppressions involving over 17-30% (10-18 of 60) of EEG sites were also prolonged and generally clustered in regions complementary to where small-scale activations and suppressions clustered. In contrast, intermediate-scale activations and suppressions (involving 7-17% of EEG sites) tended to follow stochastic dynamics and were less consistently localized. These results suggest that strong synchronizations and desynchronizations tend to occur in small-scale and large-scale networks that are spatially segregated and frequency specific. These synchronization networks may broadly segregate the relatively independent and highly cooperative oscillatory processes while phase realignments fine-tune the network configurations based on behavioral demands.

中文翻译：

---

最大和最小EEG频谱功率的时空动态

振荡性神经活动在大脑中很普遍，其相位重新排列有助于协调神经沟通。当神经活动在相互影响的种群中强烈同步（或不同步）时，相位重排可能会产生特别强烈（或微弱）的影响。我们报告说，以最大EEG频谱功率（称为激活）测量的强区域同步的时空动力学和以最小EEG频谱功率（称为抑制）测量的强区域去同步的特征是小空间的分离大规模网络。具体来说，小规模的频谱功率激活和抑制仅涉及2-7％（60个中的1-4个）EEG头皮部位（相对于随机动力学）被延长并且以特定于频率的方式一致地共定位。例如，当眼睛闭合时，θ，α，β1和β2波段（4-30 Hz）的小规模网络始终包含额叶部位，而γ波段（31-55 Hz）的小规模网络始终包含额叶部位。不论眼睛睁开还是闭合，都聚集在中后中央部位。涉及超过17-30％（60个中的10-18）的EEG部位的大规模激活和抑制作用也被延长，并且通常聚集在与小规模激活和抑制作用聚集的区域互补的区域。相比之下，中等规模的激活和抑制（涉及7-17％的EEG位点）趋向于遵循随机动态，并且局部一致性较低。这些结果表明，在空间上分离且特定于频率的小型和大型网络中，往往会发生强同步和非同步。这些同步网络可以广泛隔离相对独立且高度协作的振荡过程，而相位重新对齐则根据行为需求对网络配置进行微调。