睡眠对恐惧学习的影响及其认知神经机制

睡眠问题可能会诱发恐惧相关情绪障碍(焦虑、创伤性应激障碍、恐怖症等),研究睡眠影响恐惧学习的认知神经机制,有助于增强对恐惧相关情绪障碍的预测、诊断和治疗。以往研究表明睡眠剥夺影响恐惧习得和消退主要是通过抑制vmPFC活动,阻碍其与杏仁核的功能连接,从而导致恐惧习得增强或是消退学习受损。进一步研究发现睡眠不同阶段对恐惧学习相关脑区有独特的影响:剥夺(缺乏)快速眼动睡眠会抑制vmPFC活动、增强杏仁核、海马激活,导致恐惧习得增强,消退学习受损,此外边缘皮层的功能连接减少破坏了记忆巩固(恐惧记忆和消退记忆);而慢波睡眠主要与海马变化有关,慢波睡眠期间进行目标记忆重激活可促进恐惧消退学习。未来研究需要增加睡眠影响恐惧泛化的神经机制研究、及昼夜节律中断对恐惧消退的影响,以及关注动物睡眠研究向人类睡眠研究转化中存在的问题。     

睡眠研究若干现代理论问题

最近十年间睡眠研究日益引起全世界的重视,除我国等纷纷建立“睡眠研究会”外,并新 建“亚洲睡眠研究会”和“世界睡眠研究联合会”。本文探讨睡眠研究的若干现代理论问题,其 中包括睡眠的核心是深度慢波睡眠问题,睡眠如何受制于“２４－ｈ昼夜节律”,异相睡眠和觉醒 的比较分析,世界范围内重新评价午睡的重要性,临床睡眠疾患及其对策和介诏内源性促眠物质等。     

睡眠剥夺影响恐惧情绪加工的认知神经机制

睡眠剥夺与恐惧情绪加工的各个过程息息相关。睡眠剥夺损害了恐惧的习得过程, 而且影响着杏仁核、内侧前额叶的活动及它们之间的功能连接; 睡眠剥夺削弱了恐惧记忆的巩固和再巩固过程, 不仅破坏了恐惧记忆再巩固过程相关蛋白质和酶的合成, 同时也影响着海马、杏仁核、内侧前额叶的活动以及它们之间的功能连接; 睡眠剥夺损害了恐惧的消退, 同时也改变了海马、杏仁核等相关脑区的活动模式。未来的研究应从睡眠剥夺影响恐惧情绪加工的认知神经机制、睡眠剥夺与恐惧情绪相关障碍的关系等角度展开, 力图深入理解睡眠剥夺影响恐惧情绪加工的认知神经机制。     

学前儿童睡眠问题与语言障碍的关系

睡眠是个体身心健康发展的重要保障。学前期的睡眠问题可能会对儿童的行为、认知、语言和健康等诸多方面产生负面影响。研究表明, 睡眠呼吸障碍、夜间睡眠不足以及入睡困难等睡眠问题是学前儿童语言障碍的潜在威胁性因素。学者们提出了睡眠记忆巩固假说、警觉性假说和突触稳态假说来解释睡眠问题影响学前儿童语言发展的内在机制。这些研究结果为语言障碍的早期干预提供了一种新思路, 即通过行为干预、药物治疗、手术治疗和游戏干预等睡眠问题干预方式来提高学前儿童的语言能力。未来的研究可以进一步深入分析睡眠问题与语言障碍相关联的内在机制, 了解不同年龄段儿童睡眠问题与语言能力的关系, 以及探究融合教育背景下有效的游戏干预方式。     

老化对睡眠依赖性记忆巩固的影响

随着老化的发生和发展, 老年人的睡眠和记忆问题变得越来越突出。研究显示老年人针对程序性记忆的睡眠依赖性巩固能力受损, 而针对陈述性记忆的睡眠依赖性巩固研究结果尚存分歧。此外, 患有神经退行性疾病的老年人在正常老化的基础上伴有情景记忆睡眠依赖性巩固能力受损。未来研究应考虑同步采集脑电和脑成像数据, 探索增龄通过睡眠影响记忆的神经通路, 尝试搭建老化、睡眠以及记忆三因素的交互模型, 并从睡眠对记忆巩固影响的角度提出针对老年人记忆问题的干预措施。     

小睡对40小时睡眠剥夺条件下短时记忆的影响

睡眠剥夺(sleep deprivation,SD)是指由于各种原因引起的睡眠丢失状态,并引起情绪、学习记忆、免疫功能等一系列改变。在生活节奏日益加快的今天,许多行业都有SD的存在。有关对抗措施目前主要有应用药物,包括镇静催眠药和中枢冲经系统兴奋药;注意睡眠卫生,包括预防性睡眠、小睡(在连续工作或St)中给予不超过30min的睡眠)和恢复性睡眠;作息制度的调整;训练等。     

深度睡眠有助记忆?

<正>想要好记忆,得有好睡眠。长期以来,人们知其然而不知其所以然。现在,科学家也许找到了其中的奥秘:当人进入深度睡眠时,大脑神经元会长出新的突触,加强神经元之间的联系,从而巩固和加强记忆。这项研究成果近日发表在美国《科学》杂志上。研究负责人、美国纽约大学华人学者甘文标教授说:"这项成果对小孩子学习特别重要。如果你不停地学习,甚至牺牲睡眠来学习,那是不行的,因为大脑神经元不会有新突触形成,你根     

睡眠限制对认知功能的影响及其潜在作用机制

睡眠限制已然成为现代社会人们普遍面临的问题, 其对个体身心机能的影响备受研究者关注。众多研究表明, 睡眠限制会对注意功能、执行功能和长时记忆等不同认知领域的心理加工产生差异化影响, 且影响程度与任务类型、睡眠限制的严重程度、年龄和性别等因素相关。研究者们提出了4种主要的作用假说：唤醒假说、注意控制假说、警觉性假说以及前额皮层易感性假说。未来研究需要从关注个体间差异、使用动脉自旋标记灌注功能磁共振成像技术以及重视轻度睡眠限制的影响等角度进行深化和扩展。     

反馈相关负波：一种抑郁症的生物标记物

反馈相关负波(feedback-related negativity, FRN)是一种反映个体奖赏敏感性的脑电成分; 而抑郁症患者的特征之一是奖赏敏感性的减弱。大量横向研究发现了重度抑郁症患者(major depressive disorder, MDD)及有患抑郁症风险群体的FRN异常; 另外, 纵向研究发现FRN的异常能够预测青春期抑郁发作及抑郁症状发展, 压力、睡眠等因素在其中起调节作用。这提示FRN可能在对抑郁症的诊断及分型、抑郁高危群体的筛查及干预等方面具有潜在价值。目前关于FRN的心理功能依然存在一些争议, 在未来的研究中应该进一步明确FRN的功能和测量方法, 并探明抑郁症的异质性和共病对FRN的作用, 也应关注老年人群体中FRN与抑郁症的关系。     

睡眠对儿童执行功能的影响

近期研究表明, 睡眠总量和睡眠质量都会对儿童执行功能的发展造成影响, 在自然睡眠条件下, 睡眠质量的影响倾向于即时性, 睡眠总量的影响具有滞后性, 在实验干预条件下, 少量的睡眠延长提高了儿童的执行功能表现。睡眠问题中研究最为广泛的睡眠呼吸障碍也会对儿童的执行功能带来危害, 但由于方法的不同, 目前的研究在结论上并不一致。随着年龄的增长, 睡眠对儿童执行功能的影响会逐步降低。此外, 基因、家庭社会经济地位等内外部因素也会对研究结果产生影响。未来的研究应针对执行功能中认知灵活性这一成分进行加强。     

Declarative memory consolidation: mechanisms acting during human sleep

Of late, an increasing number of studies have shown a strong relationship between sleep and memory. Here we summarize a series of our own studies in humans supporting a beneficial influence of slow-wave sleep (SWS) on declarative memory formation, and try to identify some mechanisms that might underlie this influence. Specifically, these experiments show that declarative memory benefits mainly from sleep periods dominated by SWS, whereas there is no consistent benefit of this memory from periods rich in rapid eye movement (REM) sleep. A main mechanism of declarative memory formation is believed to be the reactivation of newly acquired memory representations in hippocampal networks that stimulates a transfer and integration of these representations into neocortical neuronal networks. Consistent with this model, spindle activity and slow oscillation-related EEG coherence increase during early sleep after intense declarative learning in humans, signs that together point toward a neocortical reprocessing of the learned material. In addition, sleep seems to provide an optimal milieu for declarative memory reprocessing and consolidation by reducing cholinergic activation and the cortisol feedback to the hippocampus during SWS.     

压力源及其与睡眠质量的现象学关系研究述评

压力源是引起压力反应的刺激或变化, 压力作用是睡眠质量下降的重要原因之一。就睡眠质量的影响而言, 近年来的研究报告主要集中于家庭、学习、工作、社会文化和疾病等5大传统压力维度。这些压力源与睡眠质量之间存在着复杂的双向的直接或间接的交互作用关系, 并因作用时间、作用强度的不同而发生不同的变化, 还因中介调节因素的相互作用而体现出复杂的个体差异。     

Sleep after learning aids memory recall

In recent years, the effect of sleep on memory consolidation has received considerable attention. In humans, these studies concentrated mainly on procedural types of memory, which are considered to be hippocampus-independent. Here, we show that sleep also has a persisting effect on hippocampus-dependent declarative memory. In two experiments, we examined high school students' ability to remember vocabulary. We show that declarative memory is enhanced when sleep follows within a few hours of learning, independent of time of day, and with equal amounts of interference during retention intervals. Sleep deprivation has a detrimental effect on memory, which was significant after a night of recovery sleep. Thus, fatigue accumulating during wake intervals could be ruled out as a confound.     

The case against memory consolidation in REM sleep

We present evidence disputing the hypothesis that memories are processed or consolidated in REM sleep. A review of REM deprivation (REMD) studies in animals shows these reports to be about equally divided in showing that REMD does, or does not, disrupt learning/memory. The studies supporting a relationship between REM sleep and memory have been strongly criticized for the confounding effects of very stressful REM deprivation techniques. The three major classes of antidepressant drugs, monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants (TCAs), and selective serotonin reuptake inhibitors (SSRIs), profoundly suppress REM sleep. The MAOIs virtually abolish REM sleep, and the TCAs and SSRIs have been shown to produce immediate (40-85%) and sustained (30-50%) reductions in REM sleep. Despite marked suppression of REM sleep, these classes of antidepressants on the whole do not disrupt learning/memory. There have been a few reports of patients who have survived bilateral lesions of the pons with few lingering complications. Although these lesions essentially abolished REM sleep, the patients reportedly led normal lives. Recent functional imaging studies in humans have revealed patterns of brain activity in REM sleep that are consistent with dream processes but not with memory consolidation. We propose that the primary function of REM sleep is to provide periodic endogenous stimulation to the brain which serves to maintain requisite levels of central nervous system (CNS) activity throughout sleep. REM is the mechanism used by the brain to promote recovery from sleep. We believe that the cumulative evidence indicates that REM sleep serves no role in the processing or consolidation of memory.     

Sleep, dreams, and memory consolidation: the role of the stress hormone cortisol

We discuss the relationship between sleep, dreams, and memory, proposing that the content of dreams reflects aspects of memory consolidation taking place during the different stages of sleep. Although we acknowledge the likely involvement of various neuromodulators in these phenomena, we focus on the hormone cortisol, which is known to exert influence on many of the brain systems involved in memory. The concentration of cortisol escalates over the course of the night's sleep, in ways that we propose can help explain the changing nature of dreams across the sleep cycle.     

Episodic memory: what can animals remember about their past?

The question of whether episodic memory, the ability to recall unique, personal experiences, is restricted to humans is a matter of current controversy. Recent work on food-storing jays suggests that several features of episodic memory may not be as exclusive to humans as previously thought. In this review we outline the critical features of episodic memory in humans, its relationship to declarative memory, and recent results revealing that jays can learn to perform a task that depends on certain features of episodic memory and can thus be considered 'episodic-like'. Finally, we compare this avian performance with a contemporary definition of human episodic memory and consider the implications for studies of hippocampal function and animal cognition.     

Learning capacities during sleep: A preliminary study in a group of schizophrenic inpatients

The relationship between sleep and learning processes is analysed in a sample of schizophrenic patients, starting from more recent hypotheses about the function of REM sleep in learning and memory processes. This is done by means of two experiments: in the first AA. evaluate the possibility to elicit a simple motor conditional reflex acquired during daytime in different sleep stages. With the second experiment daytime learning performances are evaluated with and without a reinforcement administered during REM sleep. Results for the first experiment underline a qualitative difference between REM and nREM sleep in a reflexological perspective. In nREM sleep the conditional response is better maintained than in REM sleep. The second experiment confirms the possibility to improve daytime learning performances after an additional presentation of learning material in REM. The joint study of sleep abnormalities and learning and cognitive impairment in schizophrenic patients is finally suggested.     

Sleep deprivation impairs object recognition in mice

Many studies in animals and humans suggest that sleep facilitates learning, memory consolidation, and retrieval. Moreover, sleep deprivation (SD) incurred after learning, impaired memory in humans, mice, rats, and hamsters. We investigated the importance of sleep and its timing in an object recognition task in OF1 mice subjected to 6h SD either immediately after the acquisition phase (0-6 SD) or 6h later (7-12 SD), and in corresponding undisturbed controls. Motor activity was continuously recorded with infrared sensors. All groups explored two familiar, previously encountered objects to a similar extent, both at the end of the acquisition phase and 24h later during the test phase, indicating intact familiarity detection. During the test phase 0-6 SD mice failed to discriminate between the single novel and the two familiar objects. In contrast, the 7-12 SD group and the two control groups explored the novel object significantly longer than the two familiar objects. Plasma corticosterone levels determined after SD did not differ from time-matched undisturbed controls, but were significantly below the level measured after learning alone. ACTH did not differ between the groups. Therefore, it is unlikely that stress contributed to the memory impairment. We conclude that the loss of sleep and the activities the mice engaged in during the SD, impaired recognition memory retrieval, when they occurred immediately after acquisition. The delayed SD enabled memory consolidation during the 6h when the mice were allowed to sleep, and had no detrimental effect on memory. Neither SD schedule impaired object familiarity processing, suggesting that only specific cognitive abilities were sensitive to the intervention. Sleep may either actively promote memory formation, or alternatively, sleep may provide optimal conditions of non-interference for consolidation.