Even the simplest cognitive processes involve interactions between cortical regions. To study these processes, we usually rely on averaging across several repetitions of a task or across long segments of data to reach a statistically valid conclusion. Neuronal oscillations reflect synchronized excitability fluctuations in ensembles of neurons and can be observed in electrophysiological recordings in the presence or absence of an external stimulus. Oscillatory brain activity has been viewed as sustained increase in power at specific frequency bands. However, this perspective has been challenged in recent years by the notion that oscillations may occur as transient burst-like events that occur in individual trials and may only appear as sustained activity when multiple trials are averaged together. In this review, we examine the idea that oscillatory activity can manifest as a transient burst as well as a sustained increase in power. We discuss the technical challenges involved in the detection and characterization of transient events at the single trial level, the mechanisms that might generate them and the features that can be extracted from these events to study single-trial dynamics of neuronal ensemble activity.

中文翻译：

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振荡突发作为时间耦合和信息编码的机制

即使是最简单的认知过程也涉及皮层区域之间的相互作用。为了研究这些过程，我们通常依靠对任务的多次重复或长数据段的平均来得出统计上有效的结论。神经元振荡反映了神经元集合中同步的兴奋性波动，并且可以在存在或不存在外部刺激的情况下在电生理记录中观察到。振荡的大脑活动被视为特定频段功率的持续增加。然而，近年来这种观点受到了以下观点的挑战，即振荡可能作为在个别试验中发生的瞬态突发事件而发生，并且可能仅在将多个试验平均在一起时才表现为持续活动。在这次审查中，我们研究了振荡活动可以表现为瞬时爆发以及功率持续增加的想法。我们讨论了在单次试验级别检测和表征瞬态事件所涉及的技术挑战、可能产生它们的机制以及可以从这些事件中提取的特征，以研究神经元集合活动的单次试验动力学。