Targeted reactivation of emotional memories during sleep

情绪性记忆比中性记忆更强烈、更持久。其中一个原因可能是睡眠可以加强新形成的记忆，优先考虑那些与情绪有关的记忆。在学习过程中形成的神经表征的再激活（即重新实例化）是与基于睡眠的记忆强化相关的主要机制。然而，目前尚不清楚这种再激活是否适用于加强情绪记忆，更不用说这种机制是否对情绪记忆有所增强或更有效。此外，年轻人有时会表现出消极的记忆偏见；因此，睡眠可能会特别强化这一人群的负面记忆。本项目研究基于睡眠的再激活在加强情绪记忆中的作用，再激活是否对情绪记忆和中性记忆有更强的影响，以及消极记忆和积极记忆的再激活的相对功效。因此，这项研究对睡眠科学和情感神经科学领域具有重大意义。在公共卫生方面，这项工作影响了以睡眠为基础的干预措施的设计，以操纵情绪记忆，改善心理健康和福祉。最后，该项目具有重要的教育影响，并通过参与来自系统服务不足群体的多个学士后和本科学员，促进STEM的多样性。这项提议的目的是确定睡眠期间再激活对情绪记忆巩固的作用。核心假设是，睡眠期间的再激活会加强情绪记忆，而且对情绪记忆（至少是负面记忆）的再激活比中性记忆更有效。为了验证他们的假设，研究人员在睡眠中选择性地重新激活记忆，使用目标记忆重新激活。在四个实验中，参与者在气味线索的存在下对情绪（消极或积极）和中性刺激进行编码。在随后的非快速眼动（NREM）睡眠中，一种与一半情绪和中性刺激相对应的气味被重新呈现，以便有选择地重新激活这些刺激。在快速眼动睡眠或清醒期间重新呈现气味的组被纳入比较。隔夜和一周的记忆变化在暗示和非暗示刺激以及情绪和中性刺激之间进行比较。视觉空间和图像识别任务分别用于测试空间记忆和项目记忆。多导睡眠图用于监测睡眠和测量记忆再激活的神经生理相关。本研究完成了以下工作：阐明了情绪记忆巩固的机制，包括不同睡眠阶段的贡献；提供在年轻人中观察到的消极记忆偏差的机制见解；并告知基于睡眠的再激活是否可以有针对性地操纵情绪记忆，从而有益于心理健康。此外，通过培训来自科学领域代表性不足群体的学生，开展这项研究可以增加STEM的多样性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Emotional memories are stronger and longer-lasting than neutral ones. One reason for this may be that sleep, which is known to strengthen newly-formed memories, prioritizes those associated with emotion. Reactivation (i.e. re-instantiation) of the neural representation formed during learning is the predominant mechanism linked to sleep-based memory strengthening. However, it is currently unknown whether such reactivation applies to the strengthening of emotional memories, let alone whether this mechanism is enhanced or more effective for emotional memories. Furthermore, young adults sometimes show a negative memory bias; thus, sleep may especially strengthen negative memories in this population. This project investigates the role of sleep-based reactivation in strengthening emotional memories, whether reactivation has a stronger effect on emotional versus neutral memories, and the relative efficacy of reactivation of negative and positive memories. As such, this research has substantial implications for the fields of sleep science and affective neuroscience. With regard to public health, this work impacts the design of sleep-based interventions to manipulate emotional memories for improved mental health and well-being. Finally, this project has significant educational impact and contribute to diversity in STEM through involvement of multiple post-baccalaureate and undergraduate trainees from systemically underserved groups.The objective of this proposal is to determine the role of reactivation during sleep on emotional memory consolidation. The central hypothesis is that reactivation during sleep strengthens emotional memory and that reactivation is more effective for emotional (at least negative) memories than neutral memories. To test their hypothesis, the investigators selectively reactivate memories during sleep using targeted memory reactivation. In four experiments, participants encode emotional (either negative or positive) and neutral stimuli in the presence of odor cues. An odor corresponding to half of the emotional and neutral stimuli is re-presented during subsequent non-rapid-eye movement (NREM) sleep in order to selectively reactivate these stimuli. Groups wherein odors are re-presented during REM sleep or wake are included for comparison. Overnight and over-week memory change are compared between cued and non-cued stimuli and between emotional and neutral stimuli. Visuospatial and picture recognition tasks are used to test spatial and item memory, respectively. Polysomnography is used to monitor sleep and measure neurophysiological correlates of memory reactivation. This research accomplishes the following: elucidates mechanisms of emotional memory consolidation, including the contribution of different sleep stages; provide mechanistic insight into the negative memory bias observed in young adults; and inform whether sleep-based reactivation can be targeted to manipulate emotional memory to benefit mental health. Furthermore, executing this research increase diversity in STEM through training of students from underrepresented groups in science.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.