Cousins James N, El-Deredy Wael, Parkes Laura M, Hennies Nora, Lewis Penelope A
School of Psychological Sciences, University of Manchester, Manchester M13 9PL, United Kingdom, and
School of Psychological Sciences, University of Manchester, Manchester M13 9PL, United Kingdom, and.
J Neurosci. 2014 Nov 26;34(48):15870-6. doi: 10.1523/JNEUROSCI.1011-14.2014.
Memories are gradually consolidated after initial encoding, and this can sometimes lead to a transition from implicit to explicit knowledge. The exact physiological processes underlying this reorganization remain unclear. Here, we used a serial reaction time task to determine whether targeted memory reactivation (TMR) of specific memory traces during slow-wave sleep promotes the emergence of explicit knowledge. Human participants learned two 12-item sequences of button presses (A and B). These differed in both cue order and in the auditory tones associated with each of the four fingers (one sequence had four higher-pitched tones). Subsequent overnight sleep was monitored, and the tones associated with one learned sequence were replayed during slow-wave sleep. After waking, participants demonstrated greater explicit knowledge (p = 0.005) and more improved procedural skill (p = 0.04) for the cued sequence relative to the uncued sequence. Furthermore, fast spindles (13.5-15 Hz) at task-related motor regions predicted overnight enhancement in procedural skill (r = 0.71, p = 0.01). Auditory cues had no effect on post-sleep memory performance in a control group who received TMR before sleep. These findings suggest that TMR during sleep can alter memory representations and promote the emergence of explicit knowledge, supporting the notion that reactivation during sleep is a key mechanism in this process.
记忆在初始编码后会逐渐巩固，这有时会导致从内隐知识向外显知识的转变。这种重组背后的确切生理过程尚不清楚。在这里，我们使用序列反应时任务来确定慢波睡眠期间特定记忆痕迹的靶向记忆再激活（TMR）是否能促进外显知识的出现。人类参与者学习了两个包含12个按键的序列（A和B）。这两个序列在提示顺序以及与每个手指相关的听觉音调上都有所不同（一个序列有四个音调较高的声音）。随后对参与者的夜间睡眠进行监测，并在慢波睡眠期间回放与一个学习序列相关的音调。醒来后，相对于未提示的序列，参与者对提示序列表现出了更强的外显知识（p = 0.005）和更显著的程序技能提升（p = 0.04）。此外，任务相关运动区域的快速纺锤波（13.5 - 15赫兹）预示着程序技能的夜间增强（r = 0.71，p = 0.01）。在睡眠前接受TMR的对照组中，听觉提示对睡眠后的记忆表现没有影响。这些发现表明，睡眠期间的TMR可以改变记忆表征并促进外显知识的出现，支持了睡眠期间再激活是这一过程关键机制的观点。
