Human hippocampal theta oscillations and the formation of episodic memories
Human hippocampal theta oscillations and the formation of episodic memories
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DOI：
10.1002/hipo.20937
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发表时间：
2012-04-01
期刊：
影响因子：
3.5
通讯作者：
Kahana, Michael
中科院分区：
文献类型：
--
作者：
Lega, Bradley C.;Jacobs, Joshua;Kahana, Michael
海马体θ振荡（48 Hz）对记忆形成的重要性已经通过动物研究得到了很好的证实，这促使研究人员提出了记忆和学习的综合理论，这些理论依赖于θ振荡来整合海马体和新皮层中的信息。然而，48 Hz海马体θ振荡对人类记忆形成的重要性的经验证据充其量是模棱两可的。为了澄清这种明显的种间差异，我们记录了颅内脑电图（iEEG）数据，从237海马电极在33例神经外科患者，因为他们进行了情节记忆任务。我们确定了两种不同的海马振荡模式，类似于3和类似于8 Hz，这是在传统的48 Hz人类θ波带的边缘。3 Hz慢θ振荡在成功的记忆编码过程中表现出更高的功率，并且在功能上与伽马振荡相关，但8 Hz快θ振荡不存在类似的模式。对于情景记忆，人类海马体中的慢θ振荡似乎类似于在动物中观察到的与记忆相关的θ振荡。快-θ波和慢-θ波振荡都表现出与颞叶皮层振荡相同步的证据。我们讨论我们的研究结果的背景下，最近的研究人类记忆和空间导航的电生理学，并探讨这一结果的影响，皮质海马体通信的理论。(c)2011 Wiley Periodicals，Inc.
The importance of the hippocampal theta oscillation (48 Hz) to memory formation has been well-established through studies in animals, prompting researchers to propose comprehensive theories of memory and learning that rely on theta oscillations for integrating information in the hippocampus and neocortex. Yet, empirical evidence for the importance of 48 Hz hippocampal theta oscillations to memory formation in humans is equivocal at best. To clarify this apparent interspecies discrepancy, we recorded intracranial EEG (iEEG) data from 237 hippocampal electrodes in 33 neurosurgical patients as they performed an episodic memory task. We identified two distinct patterns of hippocampal oscillations, at similar to 3 and similar to 8 Hz, which are at the edges of the traditional 48 Hz human theta band. The 3 Hz slow-theta oscillation exhibited higher power during successful memory encoding and was functionally linked to gamma oscillations, but similar patterns were not present for the 8 Hz fast-theta oscillation. For episodic memory, slow-theta oscillations in the human hippocampus appear to be analogous to the memory-related theta oscillations observed in animals. Both fast-theta and slow-theta oscillations exhibit evidence of phase synchrony with oscillations in the temporal cortex. We discuss our findings in the context of recent research on the electrophysiology of human memory and spatial navigation, and explore the implications of this result for theories of corticohippocampal communication. (c) 2011 Wiley Periodicals, Inc.