UC-Davis Center for Mind & Brain, 267 Cousteau Place, Davis, CA 95618, USA.
Psychol Sci. 2011 Nov;22(11):1434-41. doi: 10.1177/0956797611417006. Epub 2011 Oct 10.
Flexible-resource theories characterize working memory as a flexible resource that can store either a large number of low-quality representations or a small number of high-quality representations. In contrast, limited-item theories propose that the number of items that can be stored in working memory is strictly limited and cannot be increased by decreasing the quality of the representations. We tested these fundamentally different conceptualizations of working memory capacity by determining whether observers could trade quality for quantity in working memory when given incentives to do so. We found no evidence that observers could increase the number of representations by decreasing their quality in working memory, but observers could make such a trade-off at earlier processing stages. Our results show that the capacity limit of working memory is best characterized as a limit on the number of items that can be stored and not as a limit on a finely divisible resource that simultaneously determines the number and quality of the representations.
灵活资源理论将工作记忆描述为一种灵活的资源，可以存储大量低质量的表示或少量高质量的表示。相比之下，有限项目理论提出，工作记忆中可以存储的项目数量受到严格限制，并且不能通过降低表示的质量来增加。我们通过确定观察者在有激励的情况下是否可以在工作记忆中用质量换取数量，来检验工作记忆容量的这两种截然不同的概念化。我们没有发现观察者可以通过降低工作记忆中表示的质量来增加表示数量的证据，但观察者可以在早期处理阶段进行这种权衡。我们的结果表明，工作记忆的容量限制最好被描述为可以存储的项目数量的限制，而不是同时决定表示的数量和质量的可细分资源的限制。
