Investigating the Functional Role of Sleep in Waking Cognitive and Emotion Processing

睡眠是一种复杂的行为，包括在脑电中观察到的两种不同的状态(即脑波活动的电记录)。非快速眼动睡眠的特点是缓慢的大脑振荡和称为纺锤波和K-复合体的标志性波形。快速眼动睡眠是自相矛盾的，因为它看起来很像醒着的脑电，但很难唤醒睡眠者。布罗克睡眠研究实验室过去的研究调查了睡眠和睡眠中断是如何影响认知、记忆和情绪处理的。我们已经证明，睡眠中断会导致情绪失调，包括对负面图片场景和威胁面部表情的神经处理增强，但在事件相关电位大脑记录中看到的对悲伤表情的反应迟钝。*我们的长期目标是了解睡眠在清醒的认知和情绪处理中的功能作用。继续我们发表的关于完全睡眠剥夺和短期睡眠限制的研究，我们现在将更精确地研究REM和非REM睡眠机制在觉醒情绪感知中的作用。准确、快速地检测他人的情绪，以及我们环境中与情绪相关的刺激，对于决策、社交互动，甚至自我保护都是重要的。*我们最近开发了一系列新的情绪感知任务。例如，一项任务测量了在识别表情从中性动态变化的面部情绪时的检测阈值。另一项任务要求参与者判断一群人的主要情绪表达。这些任务被设计成比过去主要使用孤立呈现的静态图片刺激的研究具有更大的现实适用性。*我们将首先调查学生群体中睡眠的自然变化如何影响情绪处理(这个年龄段的睡眠持续时间差异很大)。我们还将进行一项长期的睡眠限制研究，在一周内将睡眠时间减少到每晚5小时。睡眠时间要么早，要么晚，以选择性地干扰非快速眼动和快速眼动。最后，我们将通过不同的REM睡眠剥夺和深度睡眠增强方案来操纵睡眠。在这一系列研究中，我们将记录经脉的睡眠和清醒脑电，研究睡眠脑电的时空模式及其在觉醒情绪知觉中的作用，目的是了解非快速眼动睡眠和快速眼动睡眠各自的作用。此外，我们还将继续我们最近的工作，研究性和激素(皮质醇、睾酮、雌二醇、黄体酮)和心率变异性作为睡眠中断弹性/脆弱性的标志的调节作用。*由于许多加拿大人得不到所需的睡眠，这项研究可能会帮助人们通过睡眠来优化表现(工作、学业、运动)，也可能为睡眠、情绪或行为障碍患者的干预策略提供参考。**

Sleep is a complex behaviour consisting of two distinct states observed in the EEG (i.e., electrical recordings of brain wave activity). Non-REM sleep is characterized by slow brain oscillations and signature waveforms called spindles and K-complexes. REM sleep is paradoxical in that it looks much like waking EEG, yet is difficult to awaken the sleeper. Past research from the Sleep Research Laboratory at Brock has investigated how sleep and sleep disruption affect cognition, memory, and emotion processing. We have shown that disruptions to sleep lead to emotion dysregulation including heightened neural processing of negative picture scenes and threatening facial expressions, yet blunted responses to sad expressions as seen in event-related potential brain recordings. ******Our long-term goal is to understand the functional role of sleep in waking cognitive and emotion processing. Continuing from our published studies on total sleep deprivation and short-term sleep restriction, we will now investigate the more precise roles of REM and non-REM sleep mechanisms in waking emotion perception. Accurate and rapid detection of emotion in others, and emotionally-relevant stimuli in our environment, is important for decision making, social interactions, and even self-preservation. ******We have recently developed a new battery of emotion perception tasks. For example, one task measures a threshold of detection in identifying emotion in faces that dynamically change expression from neutral. Another task requires participants to judge the predominate emotional expression in a crowd of faces. These tasks have been designed to have greater real-world applicability than past studies that have used mainly static picture stimuli presented in isolation. ******We will first investigate how natural variation in sleep in a student population affects emotion processing (sleep durations vary considerably in this age group). We will also carry out a chronic sleep restriction study where we will curtail sleep to five hours per night over a week. The sleep period will either be early or late to disrupt non-REM versus REM selectively. Last, we will manipulate sleep through separate REM sleep deprivation and deep sleep enhancement protocols. In this series of studies, we will record sleep and waking EEG from 64-channels to investigate the temporal and spatial patterns of sleep EEG and its role in waking emotion perception, with the aim to understand the respective roles of non-REM and REM sleep. As well, we will follow up on our recent work investigating the moderating role of sex and hormones (cortisol, testosterone, estradiol, progesterone) and heart rate variability as markers of resiliency/vulnerability to sleep disruption. ******As many Canadians do not get the sleep they need, this research may help people to optimize performance (work, scholastic, sport) through sleep, and may also inform intervention strategies in individuals with sleep, emotion, or behavioural disorders. **