Intra-Individual Variability in Cognitive Performance Can Befuddle the Study of Cognitive Impairments and Decline

Szymon Zdanowski, Alieke Tieks, Bertus F Jeronimus, Marij Zuidersma*

*Corresponding author for this work

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Using group-aggregated results and snapshot assessments of cognitive performance may prove problematic if the assessed construct shows substantial and rapid variation over time. To illustrate the significance of this issue, we analyzed cognitive performance data of ten older adults undergoing daily computerized cognitive assessments (CogState Brief Battery) for 36-93 days. In all cases, the day-to-day intra-individual variability was substantial when compared with group-level, between-person variability. This indicates that the results of studies using single snapshot assessments of cognitive functioning should be interpreted with caution. Additionally, group-aggregated measures of cognitive performance may not directly extrapolate to an individual.

Original languageEnglish
Pages (from-to)519-525
Number of pages7
JournalJournal of Alzheimer’s Disease
Issue number2
Early online date27-Nov-2021
Publication statusPublished - 18-Jan-2022

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