Derner Marlene, Chaieb Leila, Dehnen Gert, Reber Thomas P, Borger Valeri, Surges Rainer, Staresina Bernhard P, Mormann Florian, Fell Juergen
Department of Epileptology, Venusberg-Campus 1, University Hospital Bonn, 53127 Bonn, Germany.
Faculty of Psychology, Swiss Distance University Institute, Ueberlandstr. 12, 3900 Brig, Switzerland.
Brain Sci. 2021 Mar 12;11(3):364. doi: 10.3390/brainsci11030364.
Auditory beats are amplitude-modulated signals (monaural beats) or signals that subjectively cause the perception of an amplitude modulation (binaural beats). We investigated the effects of monaural and binaural 5 Hz beat stimulation on neural activity and memory performance in neurosurgical patients performing an associative recognition task. Previously, we had reported that these beat stimulation conditions modulated memory performance in opposite directions. Here, we analyzed data from a patient subgroup, in which microwires were implanted in the amygdala, hippocampus, entorhinal cortex and parahippocampal cortex. We identified neurons responding with firing rate changes to binaural versus monaural 5 Hz beat stimulation. In these neurons, we correlated the differences in firing rates for binaural versus monaural beats to the memory-related differences for remembered versus forgotten items and associations. In the left hemisphere, we detected statistically significant negative correlations between firing rate differences for binaural versus monaural beats and remembered versus forgotten items/associations. Importantly, such negative correlations were also observed between beat stimulation-related firing rate differences in the pre-stimulus window and memory-related firing rate differences in the post-stimulus windows. In line with concepts of homeostatic plasticity, our findings suggest that beat stimulation is linked to memory performance via shifting baseline firing levels.
听觉节拍是幅度调制信号（单耳节拍）或主观上引起幅度调制感知的信号（双耳节拍）。我们研究了单耳和双耳5赫兹节拍刺激对进行联想识别任务的神经外科患者神经活动和记忆表现的影响。此前，我们曾报道这些节拍刺激条件对记忆表现的调节方向相反。在此，我们分析了一个患者亚组的数据，该亚组患者的杏仁核、海马体、内嗅皮质和海马旁皮质植入了微丝。我们识别出对双耳和单耳5赫兹节拍刺激有放电率变化反应的神经元。在这些神经元中，我们将双耳与单耳节拍的放电率差异与记忆项目与遗忘项目及关联的记忆相关差异进行了关联。在左半球，我们检测到双耳与单耳节拍的放电率差异与记忆项目与遗忘项目/关联之间存在统计学上显著的负相关。重要的是，在刺激前窗口的节拍刺激相关放电率差异与刺激后窗口的记忆相关放电率差异之间也观察到了这种负相关。与稳态可塑性的概念一致，我们的研究结果表明节拍刺激通过改变基线放电水平与记忆表现相关联。
