科学家报告说，年龄低至14个月大的婴儿也能使用类似于成年人的心理分类概念去增加他们的工作记忆。成年人可以在他们的工作记忆中保持3至4个对象，但是他们常常会构建心理层次，通过把更大的任务分解成小片从而增加记忆容量。已经发现婴儿有能力同时记住最多3个对象。
Lisa Feigenson 和Justin Halberda发现婴儿可以使用特定的线索扩展他们的工作记忆，超过上述限制。这组科学家向婴儿展示了之前藏在盒子里的4件玩具。在一些实验中，他们偷偷地扣下了其中两件玩具。然后这组科学家观察一旦盒子空了之后婴儿还会继续搜索盒子多长时间，从而弄清楚如果婴儿记得有更多的玩具尚待发现，那么婴儿是否会用更长的时间搜索。当这4件玩具包括了两组每组两件相似物体（例如猫和汽车）、而其中一类玩具被藏了起来的时候，这些婴儿搜索的时间更长。这组作者说，这是一个证据，表明了婴儿正在使用分类概念。这组作者还发现婴儿有可能把他们的记忆容量扩展到至多6个对象。相关论文发表在美国《国家科学院院刊》（PNAS）上。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS，doi：10.1073/pnas.0709884105，Lisa Feigenson，Justin Halberda
Conceptual knowledge increases infants' memory capacity
Lisa Feigenson* and Justin Halberda
+Author Affiliations
Department of Psychological and Brain Sciences, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218
Edited by Charles R. Gallistel, Rutgers, The State University of New Jersey, Piscataway, NJ, and approved May 13, 2008 (received for review October 17, 2007)
Abstract
Adults can expand their limited working memory capacity by using stored conceptual knowledge to chunk items into interrelated units. For example, adults are better at remembering the letter string PBSBBCCNN after parsing it into three smaller units: the television acronyms PBS, BBC, and CNN. Is this chunking a learned strategy acquired through instruction? We explored the origins of this ability by asking whether untrained infants can use conceptual knowledge to increase memory. In the absence of any grouping cues, 14-month-old infants can track only three hidden objects at once, demonstrating the standard limit of working memory. In four experiments we show that infants can surpass this limit when given perceptual, conceptual, linguistic, or spatial cues to parse larger arrays into smaller units that are more efficiently stored in memory. This work offers evidence of memory expansion based on conceptual knowledge in untrained, preverbal subjects. Our findings demonstrate that without instruction, and in the absence of robust language, a fundamental memory computation is available throughout the lifespan, years before the development of explicit metamemorial strategies.
