Short-term variability in cognitive performance and the calibration of longitudinal change

• Published in: The journals of gerontology. Series B, Psychological sciences and social sciences Vol. 61; no. 3; pp. P144 - 151
• Main Authors: Salthouse, Timothy A, Nesselroade, John R, Berish, Diane E
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press for Gerontological Society of America 01.05.2006
• Series: Journals of Gerontology: Series B
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Aging - psychology; Analysis of Variance; Aptitude; Cognition; Female; Humans; Individuality; Intelligence; Longitudinal Studies; Male; Middle Aged; Neuropsychological Tests - statistics & numerical data; Psychometrics - statistics & numerical data; Reference Values; Reproducibility of Results
• ISSN: 1079-5014; 1758-5368
• DOI: 10.1093/geronb/61.3.P144

Recent studies have documented that normal adults exhibit considerable variability in cognitive performance from one occasion to another. We investigated this phenomenon in a study in which 143 adults ranging from 18 to 97 years of age performed different versions of 13 cognitive tests in three separate sessions. Substantial within-person variability was apparent across 13 different cognitive variables, and there were also large individual differences in the magnitude of within-person variability. Because people differ in the amount of short-term variability, we propose that this variability might provide a meaningful basis for calibrating change in longitudinal research. Correlations among the measures of within-person variability were very low, even after we adjusted for reliability, and there was little evidence that increased age was associated with a larger amount of within-person variability.