Subramanian Gayathri, Zelano Christina, Paller Ken A, Schechtman Eitan
Department of Psychology and Northwestern University, Evanston, Illinois, USA, 60208.
Department of Neurology, Northwestern University, Evanston, Illinois, USA, 60208.
bioRxiv. 2025 Jul 31:2025.07.25.666857. doi: 10.1101/2025.07.25.666857.
Reactivation of recently acquired memories during sleep supports their longevity. Reactivation can be biased during sleep using odors or sounds through a technique termed targeted memory reactivation (TMR). Here, we attempted to selectively weaken memories by reactivating them together with forgetting instructions. We delivered sounds to reactivate spatial memories and concurrent odors to reactivate instructions. Participants learned about the instructions in a Directed-Forgetting task performed with a list of to-be-remembered and to-be-forgotten words. One odor was linked with instructions to forget, one with instructions to remember, and a third was not assigned any meaning. During a nap, sounds previously linked with object-location learning were presented with these odors. Spatial recall was tested after sleep. Sounds produced a selective recall benefit for weakly encoded memories. However, results did not support the prediction that forgetting could be instilled by the concurrent forget odor. The encoding-strength-dependent benefit was greatest when sounds were presented together with the odor not assigned meaning, whereas the other two odors both disrupted sound-induced memory reactivation. We infer that remember and forget odors, due to the linked instructions and/or multiple learning episodes in the Directed-Forgetting task, evoked sleep-based retrieval that interfered with reactivation of spatial memories. Odors also induced a prolonged decline in sigma EEG power (12-16 Hz) that continued at least 10 s after odor offset. Overall, these findings highlight the complexity of memory consolidation during sleep when multiple memories and multiple cues are involved.
睡眠期间近期获得记忆的重新激活有助于其长期保存。通过一种称为靶向记忆重新激活（TMR）的技术，利用气味或声音可在睡眠期间使重新激活产生偏向性。在此，我们试图通过将记忆与遗忘指令一起重新激活来选择性地削弱记忆。我们播放声音以重新激活空间记忆，并同时散发气味以重新激活指令。参与者在一项定向遗忘任务中学习这些指令，该任务使用一列需记忆和需遗忘的单词来进行。一种气味与遗忘指令相关联，一种与记忆指令相关联，第三种未赋予任何意义。在午睡期间，将先前与物体位置学习相关联的声音与这些气味一同呈现。睡眠后对空间回忆进行测试。声音对编码较弱的记忆产生了选择性回忆益处。然而，结果并不支持通过同时出现的遗忘气味可灌输遗忘的预测。当声音与未赋予意义的气味一同呈现时，编码强度依赖性益处最大，而其他两种气味均干扰了声音诱导的记忆重新激活。我们推断，由于定向遗忘任务中相关联的指令和/或多次学习情节，记忆和遗忘气味引发了基于睡眠的检索，从而干扰了空间记忆的重新激活。气味还导致西格玛脑电图功率（12 - 16赫兹）持续下降，在气味消散后至少持续10秒。总体而言，这些发现凸显了涉及多个记忆和多个线索时睡眠期间记忆巩固的复杂性。
