Nakagawa Seishu, Takeuchi Hikaru, Taki Yasuyuki, Nouchi Rui, Sekiguchi Atsushi, Kotozaki Yuka, Miyauchi Carlos M, Iizuka Kunio, Yokoyama Ryoichi, Shinada Takamitsu, Yamamoto Yuki, Hanawa Sugiko, Araki Tsuyoshi, Kunitoki Keiko, Sassa Yuko, Kawashima Ryuta
Department of Human Brain Science, Institute of Development, Aging and Cancer, Tohoku UniversitySendai, Japan; Department of Psychiatry, Tohoku Medical and Pharmaceutical UniversitySendai, Japan.
Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University Sendai, Japan.
Front Psychol. 2016 Jul 28;7:1128. doi: 10.3389/fpsyg.2016.01128. eCollection 2016.
Poor sleep quality negatively affects memory performance, and working memory in particular. We investigated sleep habits related to sleep quality including sleep duration, daytime nap duration, nap frequency, and dream content recall frequency (DCRF). Declarative working memory can be subdivided into verbal working memory (VWM) and visuospatial working memory (VSWM). We hypothesized that sleep habits would have different effects on VWM and VSWM. To our knowledge, our study is the first to investigate differences between VWM and VSWM related to daytime nap duration, nap frequency, and DCRF. Furthermore, we tested the hypothesis that the effects of duration and frequency of daytime naps and DCRF on VWM and VSWM differed according to sex. We assessed 779 healthy right-handed individuals (434 males and 345 females; mean age: 20.7 ± 1.8 years) using a digit span forward and backward VWM task, a forward and backward VSWM task, and sleep habits scales. A correlation analysis was used to test the relationships between VWM capacity (VWMC) and VSWM capacity (VSWMC) scores and sleep duration, nap duration, nap frequency, and DCRF. Furthermore, multiple regression analyses were conducted to identify factors associated with VWMC and VSWMC scores and to identify sex-related differences. We found significant positive correlations between VSWMC and nap duration and DCRF, and between VWMC and sleep duration in all subjects. Furthermore, we found that working memory capacity (WMC) was positively correlated with nap duration in males and with sleep duration in females, and DCRF was positively correlated with VSWMC in females. Our finding of sex-related differences in the effects of sleep habits on WMC has not been reported previously. The associations between WMC and sleep habits differed according to sex because of differences in the underlying neural correlates of VWM and VSWM, and effectiveness of the sleep habits in males and females.
睡眠质量差会对记忆表现产生负面影响，尤其是工作记忆。我们调查了与睡眠质量相关的睡眠习惯，包括睡眠时间、白天小睡时间、小睡频率和梦境内容回忆频率（DCRF）。陈述性工作记忆可细分为言语工作记忆（VWM）和视觉空间工作记忆（VSWM）。我们假设睡眠习惯对VWM和VSWM会有不同影响。据我们所知，我们的研究是首个调查与白天小睡时间、小睡频率和DCRF相关的VWM和VSWM之间差异的研究。此外，我们检验了以下假设：白天小睡的时长和频率以及DCRF对VWM和VSWM的影响因性别而异。我们使用数字广度顺背和倒背VWM任务、顺背和倒背VSWM任务以及睡眠习惯量表对779名健康的右利手个体（434名男性和345名女性；平均年龄：20.7±1.8岁）进行了评估。采用相关分析来检验VWM容量（VWMC）和VSWM容量（VSWMC）得分与睡眠时间、小睡时间、小睡频率和DCRF之间的关系。此外，进行了多元回归分析以确定与VWMC和VSWMC得分相关的因素，并确定性别差异。我们发现，在所有受试者中，VSWMC与小睡时间和DCRF之间以及VWMC与睡眠时间之间存在显著正相关。此外，我们发现工作记忆容量（WMC）在男性中与小睡时间呈正相关，在女性中与睡眠时间呈正相关，而DCRF在女性中与VSWMC呈正相关。我们关于睡眠习惯对WMC的影响存在性别差异的发现此前尚未见报道。由于VWM和VSWM潜在神经关联的差异以及男性和女性睡眠习惯的有效性不同，WMC与睡眠习惯之间的关联因性别而异。
