荷兰研究人员发现，人的记忆力会受到深度睡眠时间长短的影响。如果没有沉睡期或者沉睡期过短，人对此前学习内容的记忆会比正常睡眠时差得多。
荷兰神经科学研究所的伊斯布兰德·范德韦夫及同事在《自然—神经学》（Nature Neuroscience）杂志发表报告说，这是由于脑内海马体结构的活动过少，而海马体结构承担着强化记忆的功能，即把信息从短期记忆转变成长期记忆。
不过，研究人员还无法说明海马体结构为什么会在缺乏沉睡时有这种反应。
范德韦夫和同事挑选了13名年龄在52岁至68岁之间身体健康的女性作为研究对象，让她们在睡前看一些图片，并对其中一半人的睡眠进行监测。当脑电波显示已进入沉睡时则发出一声轻微的嘀声，音量的大小足以对沉睡者造成干扰，但又不能将其吵醒。
第二天，接受测试者会继续看一些图片，并指出其中是否有昨天看过的图片。在学习和回忆的过程中，研究人员会记录测试者的大脑活跃程度。结果显示，虽然两组测试者睡了同样长的时间，但缺乏沉睡显然对记忆力造成了影响。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature Neuroscience Published online: 18 January 2009 | doi:10.1038/nn.2253
Sleep benefits subsequent hippocampal functioning
Ysbrand D Van Der Werf1,2, Ellemarije Altena1,3, Menno M Schoonheim4, Ernesto J Sanz-Arigita1,4, José C Vis1, Wim De Rijke2 & Eus J W Van Someren1,2
Sleep before learning benefits memory encoding through unknown mechanisms. We found that even a mild sleep disruption that suppressed slow-wave activity and induced shallow sleep, but did not reduce total sleep time, was sufficient to affect subsequent successful encoding-related hippocampal activation and memory performance in healthy human subjects. Implicit learning was not affected. Our results suggest that the hippocampus is particularly sensitive to shallow, but intact, sleep.
1 Department of Sleep and Cognition, Netherlands Institute for Neuroscience, an institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105BA Amsterdam, The Netherlands.
2 Departments of Clinical Neurophysiology, Vrije Universiteit Medical Center, PO Box 7057, 1007 MB Amsterdam, The Netherlands.
3 Neurology, Vrije Universiteit Medical Center, PO Box 7057, 1007 MB Amsterdam, The Netherlands.
4 Radiology, Vrije Universiteit Medical Center, PO Box 7057, 1007 MB Amsterdam, The Netherlands.
