Timing, instructions, and inhibitory control: some missing factors in the age and memory debate.

In response to Luszcz and Bryan, we point to three omitted factors that have been found to influence the presence and size of age differences in memory tasks and that, as such, have important implications for resolving theoretical questions about aging and memory. These include: (1) age differences in circadian rhythms and testing time effects that are associated with such differences; (2) instructions that may have a particularly disruptive effect on older adults, and (3) inhibitory control differences that have an age-related impact on both estimates of working memory span and on performance in multitask studies. Copyright 1999 S. Karger AG, Basel