2019 Volume 38 Issue 1 Pages 77-89
As the ratio of elderly people increases worldwide, it is becoming more important to understand cognitive aging. Older adults show much greater interindividual differences than young adults. These differences grow with age, making it impossible for some older adults to participate as research volunteers in aging studies. Relatedly, results of cognitive aging studies are affected by sampling and by selection of cross-sectional/longitudinal research methods. These issues are discussed in the context of several behavioral and neuroimaging studies. Factors affecting increased interindividual differences are also reviewed. Researchers should pay attention to these factors and to characteristics of research methods when planning and interpreting the results of studies on cognitive aging.
