Taking a computational approach to aging: the SPAN theory of working memory.
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.
Byrne
M D
MD
School of Psychology, Georgia Institute of Technology, USA. byrne@acm.org
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001288:Attention / Q000502:physiology; D003198:Computer Simulation; D006801:Humans; D008433:Mathematics; D008570:Memory, Short-Term / Q000502:physiology*; D008960:Models, Psychological; D009010:Monte Carlo Method; D011340:Problem Solving / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology*; D012153:Retention, Psychology / Q000502:physiology; D013598:Systems Theory; D013997:Time Factors; D014836:Volition / Q000502:physiology