Memory formation and reinstatement are thought to lock to the hippocampal theta rhythm, predicting that encoding and retrieval processes appear rhythmic themselves. Here, we show that rhythmicity can be observed in behavioral responses from memory tasks, where participants indicate, using button presses, the timing of encoding and recall of cue-object associative memories. We find no evidence for rhythmicity in button presses for visual tasks using the same stimuli, or for questions about already retrieved objects. The oscillations for correctly remembered trials center in the slow theta frequency range (1-5 Hz). Using intracranial EEG recordings, we show that the memory task induces temporally extended phase consistency in hippocampal local field potentials at slow theta frequencies, but significantly more for remembered than forgotten trials, providing a potential mechanistic underpinning for the theta oscillations found in behavioral responses.

记忆的形成和恢复被认为会锁定海马体的 theta 节律，预测编码和检索过程本身会出现节律。在这里，我们表明可以在记忆任务的行为反应中观察到节律性，参与者使用按钮按下指示编码和回忆提示对象联想记忆的时间。我们没有发现使用相同刺激的视觉任务或有关已检索对象的问题的按钮按下有节奏性的证据。正确记忆试验的振荡集中在缓慢的 theta 频率范围 (1-5 Hz)。使用颅内脑电图记录，我们表明记忆任务在慢 theta 频率下诱导海马局部场电位的时间延长相位一致性，但记忆试验明显多于遗忘试验，