Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg-August University of Göttingen, 37075, Göttingen, Germany; Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, 55455, USA.
Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg-August University of Göttingen, 37075, Göttingen, Germany.
Brain Stimul. 2020 Mar-Apr;13(2):474-483. doi: 10.1016/j.brs.2019.12.019. Epub 2019 Dec 19.
Long-term recognition memory depends both on initial encoding and on subsequent recognition processes.
In this study we aimed at improving long-term memory by modulating posterior parietal brain activity during the encoding process. If this area is causally involved in memory encoding, its facilitation should lead to behavioral improvement. Based on the dual-process memory framework, we also expected that the neuromodulation would dissociate subsequent familiarity-based and recollection-based recognition.
We investigated the role of the posterior parietal brain oscillations in facial memory formation in three separate experiments using electroencephalography (EEG), functional magnetic resonance imaging (fMRI), and model-driven, multi-electrode transcranial alternating current stimulation (tACS).
Using fMRI and EEG, we confirmed that the right posterior parietal cortex is an essential node that promotes the encoding of long-term memories. We found that single-trial low theta power in this region predicts subsequent long-term recognition. On this basis, we fine-tuned the spatial and frequency settings of tACS during memory encoding. Model-driven tACS over the right posterior brain area augmented subsequent long-term recognition memory and particularly the familiarity of the observed stimuli. The recollection process, and short-term task performance as control remained unchanged. Control stimulation over the left hemisphere had no behavioral effect.
We conclude that the right posterior brain area is crucial in long-term memory encoding.
长期识别记忆既依赖于初始编码，也依赖于后续的识别过程。
本研究旨在通过调节编码过程中顶后脑区的脑活动来改善长期记忆。如果该区域在记忆编码中起因果作用，那么它的促进作用应该会导致行为改善。基于双过程记忆框架，我们还期望神经调节会区分后续基于熟悉度和基于回忆的识别。
我们使用脑电图（EEG）、功能磁共振成像（fMRI）和基于模型的多电极经颅交流电刺激（tACS）在三个独立的实验中研究了顶后脑区脑振荡在面部记忆形成中的作用。
使用 fMRI 和 EEG，我们证实了右顶后皮质是促进长期记忆编码的关键节点。我们发现，该区域的单次试验低theta 功率可以预测随后的长期识别。在此基础上，我们在记忆编码过程中对 tACS 的空间和频率设置进行了微调。针对右后脑区的经颅交流电刺激增强了随后的长期识别记忆，特别是对观察到的刺激的熟悉度。回忆过程和作为对照的短期任务表现保持不变。对左半球的对照刺激没有行为影响。
我们的结论是，右后脑区在长期记忆编码中至关重要。
