Older Adults Perform More Consistently on Cognitive Tasks Than Younger Adults

Is your doctor testing your cognitive ability over several days?
http://pss.sagepub.com/content/24/9/1747.abstract

1. Florian Schmiedek1,2
2. Martin Lövdén1,3,4
3. Ulman Lindenberger1

1. ¹Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany
2. ²German Institute for International Educational Research, Frankfurt, Germany
3. ³Aging Research Center, Karolinska Institutet and Stockholm University
4. ⁴Department of Psychology, Lund University

1. Florian Schmiedek, German Institute for International Educational Research, Schloßstr. 29, 60486 Frankfurt am Main, Germany E-mail: schmiedek@dipf.de

1. Author Contributions F. Schmiedek, M. Lövdén, and U. Lindenberger designed the study. F. Schmiedek organized the data collection and conducted the analysis. F. Schmiedek, M. Lövdén, and U. Lindenberger discussed and interpreted the findings and wrote the manuscript.

Abstract

People often attribute poor performance to having bad days. Given that cognitive aging leads to lower average levels of performance and more moment-to-moment variability, one might expect that older adults should show greater day-to-day variability and be more likely to experience bad days than younger adults. However, both researchers and ordinary people typically sample only one performance per day for a given activity. Hence, the empirical basis for concluding that cognitive performance does substantially vary from day to day is inadequate. On the basis of data from 101 younger and 103 older adults who completed nine cognitive tasks in 100 daily sessions, we show that the contributions of systematic day-to-day variability to overall observed variability are reliable but small. Thus, the impression of good versus bad days is largely due to performance fluctuations at faster timescales. Despite having lower average levels of performance, older adults showed more consistent levels of performance across days.