Neuro-Cognitive Studies of Sleep and the Generalization of Emotional Learning and Threat Detection

睡眠的神经认知研究以及情绪学习和威胁检测的推广

• 批准号: 1461009
• 负责人: Mark Gluck
• 金额: $ 56.17万
• 依托单位: Rutgers University Newark
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-15 至 2019-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1461009&HistoricalAwards=false
• 关键词: Neuro; Cognitive; Studies; Sleep; Generalization

The ability to encode emotionally laden memories and exploit them efficiently in novel situations is among the most important learning capabilities of an individual. From correct recognition of facial expressions in emotionally-charged social situations, to discrimination between threatening and safe signals in fight-or-flight scenarios, the way we build on our past emotional experiences to decipher unfamiliar conditions strongly determines our ability to survive and function adaptively. Contemporary research on sleep and memory indicates that sleep plays a key role in the generalization of past experiences to novel situations, a process involving core brain regions such as the hippocampus, amygdala and medial prefrontal cortex. However, significant inconsistencies exist between findings regarding the effect of sleep on emotional versus non-emotional memories. These inconsistencies pose a significant obstacle for reaching a comprehensive understanding of how sleep affects memory and learning in general, and how it differentially affect fear memories in particular. Understanding how sleep assists processing of emotional memories can bridge those gaps, as well as contribute broader knowledge to inform any future developments in prevention and treatment of anxiety disorders that involve both sleep and memory generalization disruptions, specifically post-traumatic stress disorder for which sleep irregularities have been emphasized as a key factor.Current studies suggest that generalizing acquired associations of non-emotional stimuli to novel situations is influenced by a specific sleep stage termed Slow-Wave-Sleep (SWS). Processing of emotional stimuli, on the other hand, was shown to be influenced mostly by another sleep stage, Rapid-Eye-Movement (REM) sleep. These potential inconsistencies raise the question of how sleep influences processes requiring a combination of the two, namely, generalization of emotional memories. These issues, however, were only sporadically addressed in human studies, and were mainly concentrated on a narrow definition of memory generalization. The current project will attempt to elucidate the mechanism involved in the way sleep affects fear generalization and threat detection in humans, addressing the empirical and theoretical gaps by: (1) Employing long-term monitoring of sleep stages prior to, and following, fear learning, that may be more sensitive in detecting relations between cognitive mechanisms and sleep characteristics compared to studies using only single-night monitoring (2) Using novel neurocognitive assessments of fear generalization processes, focusing on discriminative learning of threat and safe stimuli, accompanied by functional neuroimaging (fMRI); (3) Studying computational network models of the key brain regions known to be involved in fear learning to simulate and interpret the experimental findings. These three approaches will allow establishing how fear generalization is affected by individual baselines of sleep patterns, whether it is differently affected by the type of stimuli generalization (discriminative versus similarity-based) required by the behavioral task, and what the level of involvement of the key brain regions is in each type of generalization task and in relation to the individual sleep patterns.

对情感记忆进行编码并在新的情况下有效利用它们的能力是个人最重要的学习能力之一。从在充满情感的社交场合中正确识别面部表情，到在战斗或逃跑场景中区分威胁和安全信号，我们建立在过去的情感经验基础上解读不熟悉条件的方式强烈地决定了我们的生存能力和适应能力。当代关于睡眠和记忆的研究表明，睡眠在将过去的经验概括为新的情况方面起着关键作用，这一过程涉及海马体，杏仁核和内侧前额叶皮层等核心大脑区域。然而，关于睡眠对情绪记忆和非情绪记忆的影响，研究结果之间存在着显著的不一致。这些不一致性对全面了解睡眠如何影响记忆和学习，以及如何特别影响恐惧记忆构成了重大障碍。了解睡眠如何帮助情绪记忆的处理可以弥合这些差距，并提供更广泛的知识，以告知任何未来的发展，在预防和治疗焦虑症，涉及睡眠和记忆泛化中断，特别是创伤后应激障碍，睡眠不规律被强调为一个关键因素。目前的研究表明，对新情况的情绪刺激受到称为慢波睡眠（SWS）的特定睡眠阶段的影响。另一方面，对情绪刺激的处理被证明主要受另一个睡眠阶段的影响，即快速眼动（REM）睡眠。这些潜在的不一致性提出了一个问题，即睡眠如何影响需要两者结合的过程，即情绪记忆的概括。然而，这些问题在人类研究中只是零星地提到，而且主要集中在记忆泛化的狭义定义上。目前的项目将试图阐明睡眠影响人类恐惧泛化和威胁检测的方式所涉及的机制，通过以下方式解决经验和理论差距：（1）对恐惧学习前后的睡眠阶段进行长期监测，与仅使用单夜监测的研究相比，在检测认知机制和睡眠特征之间的关系方面可能更敏感（2）采用新的恐惧泛化过程的神经认知评估方法，重点关注威胁和安全刺激的区分性学习，并辅以功能性神经成像（fMRI）;（3）研究已知参与恐惧学习的关键脑区的计算网络模型，以模拟和解释实验结果。这三种方法将允许建立恐惧泛化如何受到睡眠模式的个体基线的影响，它是否受到行为任务所需的刺激泛化类型（区分性与基于相似性）的不同影响，以及关键大脑区域参与每种类型的泛化任务以及与个体睡眠模式相关的水平。