National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China; Lab of Light and Physio-psychological Health, School of Psychology, South China Normal University, Guangzhou 510631, China.
National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China; Lab of Light and Physio-psychological Health, School of Psychology, South China Normal University, Guangzhou 510631, China.
Int J Psychophysiol. 2022 Sep;179:21-29. doi: 10.1016/j.ijpsycho.2022.06.013. Epub 2022 Jun 24.
Taking a short midday nap has been associated with higher alertness and better cognitive task performance. Yet, the mechanisms associated with nap-dependent performance enhancement are unclear. The current study was conducted to explore the impact of physiological arousal during cognitive task and sleep architecture during a pre-task nap on post-nap behavioral outcomes. A within-subjects design (N = 18) was employed, in which participants either took a nap or remained awake for 40 min during the post-lunch period. The psychomotor vigilance test (PVT) and n-back task were administered to assess sustained attention and working memory, respectively, with each task including one block of easy trials and one block of difficult trials. Results showed that a short midday nap improved sustained attention but not working memory. In addition, a midday nap induced lower physiological arousal during the performance on both cognitive tasks, with relatively higher delta and lower beta activity. The relative power of theta and alpha were positively correlated with performance on the easy PVT, whereas the alpha power was negatively correlated with performance on the difficult PVT, and the theta power was negatively correlated with reaction speed in the n-back task regardless of the task difficulty. Meanwhile, the shorter total sleep time and longer time of wake after sleep onset were associated with the faster overall reaction speed in PVT easy trials. These findings suggested that both changes in physiological arousal and sleep variables might account for changes in task performance after a short midday nap.
午休小睡与更高的警觉性和更好的认知任务表现相关。然而，与午睡依赖性表现增强相关的机制尚不清楚。本研究旨在探讨认知任务期间的生理唤醒和预任务午睡期间的睡眠结构对午睡后行为结果的影响。采用了被试内设计（N=18），其中参与者在午餐后时段要么小睡 40 分钟，要么保持清醒。使用心理运动警觉测试（PVT）和 n-back 任务分别评估持续注意力和工作记忆，每个任务包括一个简单任务块和一个困难任务块。结果表明，短暂的午休时间提高了持续注意力，但没有改善工作记忆。此外，午休期间在执行两项认知任务时的生理唤醒水平较低，Delta 波活动相对较高，Beta 波活动相对较低。Theta 和 Alpha 波的相对功率与简单 PVT 的表现呈正相关，而 Alpha 波的功率与困难 PVT 的表现呈负相关，Theta 波的功率与 n-back 任务的反应速度呈负相关，无论任务难度如何。同时，总睡眠时间较短和睡眠后觉醒时间较长与 PVT 简单任务的整体反应速度较快相关。这些发现表明，生理唤醒和睡眠变量的变化可能解释了短暂午休后任务表现的变化。
