| Abstract: | The decline of working memory capacity associated with normal adult aging is well-known. What is less well established is the cause of this decline. One prominent proposal is that working memory decline is caused by a reduction in basic information-processing speed, but this account has lacked a demonstration that general slowing is computationally sufficient to produce a decrease in working memory capacity. This article presents a production system theory of working memory (SPAN) based on established mechanisms: slowing, decay, and displacement. Models of 2 tasks—digit symbol and computation span—which have been prominent in research on slowing, are presented in detail. These models demonstrate that slowing is sufficient to produce differences in these tasks, and they provide a quantitative match to observed young-old differences as well. This advance for slowing theory also demonstrates the viability of computational tools in aging research. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
