Hippocampal pattern completion is linked to gamma power increases and alpha power decreases during recollection
Hippocampal pattern completion is linked to gamma power increases and alpha power decreases during recollection
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DOI：
10.7554/elife.17397
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发表时间：
2016-07
期刊：
影响因子：
7.7
通讯作者：
B. Staresina;Sebastian Michelmann;Mathilde Bonnefond;O. Jensen;N. Axmacher;J. Fell
中科院分区：
文献类型：
--
作者：
B. Staresina;Sebastian Michelmann;Mathilde Bonnefond;O. Jensen;N. Axmacher;J. Fell
当我们遇到一个简单的线索时，我们是如何找回生动的记忆的？计算模型表明，这一壮举是通过涉及海马体的模式完成过程来完成的。然而，海马模式完成及其潜在机制的经验证据仍然难以捉摸。在这里，我们记录了人类参与者进行联想记忆任务的直接颅内脑电图。对于每个研究（编码）和测试（检索）事件，我们得出的时间-频率分辨的表征模式在海马体和不同的记忆结果的模式恢复的程度进行了比较。结果表明，成功的联想识别（AR）产生增强的事件特定的恢复的编码模式相比，非联想项目识别（IR）。此外，我们发现γ功率（50-90 Hz）增加-结合α功率（8-12 Hz）降低不仅区分AR与IR，而且与海马恢复水平相关。这些结果将单次海马模式完成与情景回忆联系起来，并揭示了伽马和α波段的振荡动力学如何协调这些记忆过程。DOI：http://dx.doi.org/10.7554/eLife.17397.001网站
How do we retrieve vivid memories upon encountering a simple cue? Computational models suggest that this feat is accomplished by pattern completion processes involving the hippocampus. However, empirical evidence for hippocampal pattern completion and its underlying mechanisms has remained elusive. Here, we recorded direct intracranial EEG as human participants performed an associative memory task. For each study (encoding) and test (retrieval) event, we derived time-frequency resolved representational patterns in the hippocampus and compared the extent of pattern reinstatement for different mnemonic outcomes. Results show that successful associative recognition (AR) yields enhanced event-specific reinstatement of encoding patterns compared to non-associative item recognition (IR). Moreover, we found that gamma power (50–90 Hz) increases – in conjunction with alpha power (8–12 Hz) decreases not only distinguish AR from IR, but also correlate with the level of hippocampal reinstatement. These results link single-shot hippocampal pattern completion to episodic recollection and reveal how oscillatory dynamics in the gamma and alpha bands orchestrate these mnemonic processes. DOI: http://dx.doi.org/10.7554/eLife.17397.001