Lo Edwyn B L, Laferriere Lilian J C, Stewart Matthew R, Milanovic Melissa, Kinney Melinda, Bowie Christopher R, Dringenberg Hans C
Department of Psychology, Queen's University, Kingston, Ontario, Canada.
Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada.
Nat Sci Sleep. 2021 Feb 10;13:141-152. doi: 10.2147/NSS.S297872. eCollection 2021.
Sleep, both overnight and daytime naps, can facilitate the consolidation of declarative memories in healthy humans. However, it is unclear whether such beneficial effects of sleep occur in special populations, such as individuals with elevated neuropsychiatric symptoms, and if they apply to clinically relevant material that may have personal significance to those populations.
We examined memory retention over a 60-minute interval of wakefulness or nap opportunity in participants with low or elevated scores (≤13 and ≥21, respectively) on the Beck Depression Inventory-II (BDI-II). Memory for depression-related information was assessed by (a) free-recall of a video depicting a personal experience narrative of the impact of depression on cognition and workplace performance; and (b) a paired-associates task linking depression-related cognitive symptoms to appropriate coping strategies.
The results showed no overall difference in recall between the nap and waking condition. However, across the full sample of participants, there were significant positive correlations between total sleep time and paired associates recall, and slow wave sleep (SWS) percentage and story free recall performance. Unexpectedly, participants with elevated BDI-II scores exhibited better free-recall performance compared to those with low scores.
These results suggest that sleep, specifically SWS, may stabilize memories for clinically relevant information in populations with low and elevated depressive symptoms. The superior recall in participants with elevated-BDI scores may be related to the personal significance and stronger encoding of depression-related information. These observations raise the possibility that mnemonic deficits in depressed patients may be, at least in part, related to the type of information used to assess memory performance.
夜间睡眠和白天小睡都有助于健康人巩固陈述性记忆。然而，尚不清楚睡眠的这种有益效果是否发生在特殊人群中，比如神经精神症状加重的个体，以及这些效果是否适用于对这些人群可能具有个人意义的临床相关材料。
我们在贝克抑郁量表第二版（BDI-II）得分低（≤13分）或高（≥21分）的参与者中，考察了在60分钟清醒或小睡期间的记忆保持情况。通过以下方式评估对抑郁相关信息的记忆：（a）自由回忆一段描述抑郁对认知和工作场所表现影响的个人经历叙述的视频；（b）一项将抑郁相关认知症状与适当应对策略联系起来的配对联想任务。
结果显示小睡和清醒状态下的回忆没有总体差异。然而，在所有参与者样本中，总睡眠时间与配对联想回忆之间，以及慢波睡眠（SWS）百分比与故事自由回忆表现之间存在显著正相关。出乎意料的是，BDI-II得分高的参与者比得分低的参与者表现出更好的自由回忆成绩。
这些结果表明，睡眠，特别是慢波睡眠，可能会稳定抑郁症状轻和重的人群中与临床相关信息的记忆。BDI得分高的参与者回忆成绩更好，可能与抑郁相关信息的个人意义和更强的编码有关。这些观察结果提出了一种可能性，即抑郁症患者的记忆缺陷可能至少部分与用于评估记忆表现的信息类型有关。
