PNAS：美国研究显示午睡有助提高学龄前儿童记忆力

   美国阿默斯特马萨诸塞大学研究人员23日在美国《国家科学院学报》上报告说，人们对于幼童午睡的价值知之甚少，美国的一些学前教育机构甚至开始取消午睡，以便增加教学时间。为此，他们招募了40名学龄前儿童进行研究，让这些儿童观看图片格子，并记忆不同图片的位置。儿童在上午观看图片格子，随即接受一次记忆测试，然后下午再测试一次。

    研究人员发现，尽管这些儿童在学习之后的测试成绩类似，但那些午睡过的儿童在下午的测试中平均记忆准确率为75％，明显好于未午睡儿童的65％。此外，午睡儿童在第二天的测试成绩也显著好于没有午睡的儿童，这说明午睡的益处无法通过夜间睡眠弥补。

    该研究负责人丽贝卡·斯潘塞说，这项研究为午睡对学龄前儿童很重要的观点提供了证据，因此不仅应该让学龄前儿童午睡，而且应创造条件鼓励他们午睡。有关教育机构应出台学龄前儿童午睡指南，并进一步研究如何保证、促进他们午睡。

英文摘要

Sleep spindles in midday naps enhance learning in preschool children

Laura Kurdziela, Kasey Duclosb,c, and Rebecca M. C. Spencera,b,1

Despite the fact that midday naps are characteristic of early childhood, very little is understood about the structure and function of these sleep bouts. Given that sleep benefits memory in young adults, it is possible that naps serve a similar function for young children. However, children transition from biphasic to monophasic sleep patterns in early childhood, eliminating the nap from their daily sleep schedule. As such, naps may contain mostly light sleep stages and serve little function for learning and memory during this transitional age. Lacking scientific understanding of the function of naps in early childhood, policy makers may eliminate preschool classroom nap opportunities due to increasing curriculum demands. Here we show evidence that classroom naps support learning in preschool children by enhancing memories acquired earlier in the day compared with equivalent intervals spent awake. This nap benefit is greatest for children who nap habitually, regardless of age. Performance losses when nap-deprived are not recovered during subsequent overnight sleep. Physiological recordings of naps support a role of sleep spindles in memory performance. These results suggest that distributed sleep is critical in early learning; when short-term memory stores are limited, memory consolidation must take place frequently.