Viczko Jeremy, Sergeeva Valya, Ray Laura B, Owen Adrian M, Fogel Stuart M
The Brain & Mind Institute, Western University, London, Ontario N6A 5B7, Canada.
Department of Psychology, Western University, London, Ontario N6A 5C2, Canada.
Learn Mem. 2018 Jan 16;25(2):67-77. doi: 10.1101/lm.044719.116. Print 2018 Feb.
Sleep facilitates the consolidation (i.e., enhancement) of simple, explicit (i.e., conscious) motor sequence learning (MSL). MSL can be dissociated into egocentric (i.e., motor) or allocentric (i.e., spatial) frames of reference. The consolidation of the allocentric memory representation is sleep-dependent, whereas the egocentric consolidation process is independent of sleep or wake for explicit MSL. However, it remains unclear the extent to which sleep contributes to the consolidation of implicit (i.e., unconscious) MSL, nor is it known what aspects of the memory representation (egocentric, allocentric) are consolidated by sleep. Here, we investigated the extent to which sleep is involved in consolidating implicit MSL, specifically, whether the egocentric or the allocentric cognitive representations of a learned sequence are enhanced by sleep, and whether these changes support the development of explicit sequence knowledge across sleep but not wake. Our results indicate that egocentric and allocentric representations can be behaviorally dissociated for implicit MSL. Neither representation was preferentially enhanced across sleep nor were developments of explicit awareness observed. However, after a 1-wk interval performance enhancement was observed in the egocentric representation. Taken together, these results suggest that like explicit MSL, implicit MSL has dissociable allocentric and egocentric representations, but unlike explicit sequence learning, implicit egocentric and allocentric memory consolidation is independent of sleep, and the time-course of consolidation differs significantly.
睡眠有助于简单、显性（即有意识的）运动序列学习（MSL）的巩固（即增强）。MSL可分为以自我为中心（即运动）或以外界为中心（即空间）的参照系。以外界为中心的记忆表征的巩固依赖于睡眠，而以自我为中心的巩固过程对于显性MSL而言独立于睡眠或清醒状态。然而，睡眠对隐性（即无意识的）MSL巩固的贡献程度仍不清楚，也不知道睡眠巩固了记忆表征的哪些方面（以自我为中心、以外界为中心）。在此，我们研究了睡眠在巩固隐性MSL中的参与程度，具体而言，睡眠是否增强了所学序列的以自我为中心或以外界为中心的认知表征，以及这些变化是否支持在睡眠而非清醒期间显性序列知识的发展。我们的结果表明，对于隐性MSL，以自我为中心和以外界为中心的表征在行为上是可分离的。在睡眠期间，两种表征均未得到优先增强，也未观察到显性意识的发展。然而，在1周的间隔后，观察到以自我为中心的表征有表现增强。综上所述，这些结果表明，与显性MSL一样，隐性MSL具有可分离的以自我为中心和以外界为中心的表征，但与显性序列学习不同，隐性以自我为中心和以外界为中心的记忆巩固独立于睡眠，且巩固的时间进程有显著差异。
