Strategically strengthening declarative memories during sleep

准确记忆信息的能力是人类成功的核心。然而，随着每天都有新的信息增加，人脑不断扩大的记忆库需要不断地重组。如何才能最大限度地利用大量涌入的新信息？在国家科学基金会的资助下，西北大学的肯·帕勒博士正在研究一个有趣的假说，即睡眠中的大脑活动有助于有效存储记忆。虽然有些记忆很快就会消失，但另一些记忆会持续数年，这大概是因为大脑网络的一系列变化。目前还不清楚记忆是如何持久存储在人脑中的，以及睡眠可能在多大程度上有所帮助。这个项目探索了一种可以改善内存存储的新方法。当一个人睡觉时，与先前学习的信息相关的特定声音被轻柔地呈现出来。从理论上讲，这些声音可以在睡眠中促使记忆排练，导致在醒来后不久测试的记忆力有所改善。因此，这些程序提供了一个机会来观察睡眠的潜在好处--增强记忆，这可能是持久记忆存储的基础。这个项目探索了这些“睡眠声音”有效的过程，包括(A)确定睡眠声音是否可以产生长期记忆改善，(B)比较空间位置、单词和特定手动动作的学习，以及(C)显示睡眠的哪些阶段适合这种记忆增强。实验还比较了参与者在醒着和睡着时可能增强的记忆力。该项目包括对大脑活动的脑电测量，以进一步阐明睡眠期间改善记忆的大脑机制。虽然人们普遍认为新的信息不能在睡眠中学习，但睡前学习的信息显然可以在睡眠中排练。这个项目提供了新的证据，说明一段时间的睡眠如何能够改善记忆，以及如何将这种改善集中在特定的信息上。通过这个项目获得的结果为理解总体上的记忆存储，特别是睡眠期间的记忆处理提供了新的杠杆。这个项目正在扩大关于睡眠在稳定记忆和形成这些记忆之间的相互联系中所起的特殊作用的知识，这些联系可以成为创造性思维的基础。通过促进对睡眠中记忆是如何增强的理解，最终将产生促进课堂上的最佳教育结果、增强新信息和技能的日常获取以及在法律环境中评估记忆等应用的影响。对睡眠和学习的欣赏也有助于强调适当的睡眠对公共健康的重要性。

The ability to accurately remember information is central to human success. Yet, as new information is added every day, the human brain's expanding storehouse of memories requires continual restructuring. How can the massive influx of new information be used to best advantage? With funding from the National Science Foundation, Ken Paller, Ph.D., of Northwestern University is investigating the intriguing hypothesis that brain events during sleep are instrumental for effective memory storage. Although some memories rapidly fade away, others endure for years, presumably because of a progression of changes in brain networks. It remains unclear how memories are enduringly stored in the human brain, and to what extent sleep might be helpful. This project explores a novel way in which memory storage can be improved. Specific sounds related to information learned previously are presented softly while an individual sleeps. These sounds can in theory prompt memory rehearsal during sleep, leading to an improvement in memory tested a short time after awakening. The procedures thus provide an opportunity to observe a potential benefit of sleep -- memory strengthening that could underlie lasting memory storage. This project explores the procedures whereby these "sleep-sounds" are effective, including (a) determining whether long-lasting memory improvement can be produced by sleep-sounds, (b) comparing learning of spatial locations, of words, and of specific manual actions, and (c) showing which stages of sleep are amenable to this memory strengthening. Experiments also compare the memory strengthening that is possible when participants are awake versus asleep. Electroencephalographic measures of brain activity are included in the project to further elucidate the brain mechanisms of memory improvement during sleep. Although it is widely thought that new information cannot be learned during sleep, information learned before going to sleep can apparently be rehearsed during sleep. This project provides new evidence about how a period of sleep can lead to memory improvement and how that improvement can be focused on specific information.Results obtained through this project provide new leverage on understanding memory storage in general, and memory processing during sleep in particular. This project is expanding knowledge about the special role that sleep can play in the stabilization of memories and in the formation of interconnections among these memories that can be the basis for creative thinking. By advancing understanding of how memories are strengthened during sleep, implications will ultimately arise for promoting optimal educational outcomes in the classroom, enhancing the daily acquisition of new information and skills, and evaluating memory in legal contexts, among other applications. An appreciation of sleep and learning will also aid efforts to emphasize the importance of suitable amounts of sleep for public health.