HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Cited by other online articles Google Scholar Articles by Hultsch, D. F. Articles by Dixon, R. A. Articles citing this Article PubMed PubMed Citation Articles by Hultsch, D. F. Articles by Dixon, R. A.

Variability in Reaction Time Performance of Younger and Older Adults

^a Department of Psychology, University of Victoria, British Columbia, Canada

David F. Hultsch, Department of Psychology, University of Victoria, Victoria, British Columbia, Canada V8W 3P5 E-mail: dfh{at}uvic.ca.

Decision Editor: Margie E. Lachman, PhD

Age differences in three basic types of variability were examined: variability between persons (diversity), variability within persons across tasks (dispersion), and variability within persons across time (inconsistency). Measures of variability were based on latency performance from four measures of reaction time (RT) performed by a total of 99 younger adults (ages 17–36 years) and 763 older adults (ages 54–94 years). Results indicated that all three types of variability were greater in older compared with younger participants even when group differences in speed were statistically controlled. Quantile-quantile plots showed age and task differences in the shape of the inconsistency distributions. Measures of within-person variability (dispersion and inconsistency) were positively correlated. Individual differences in RT inconsistency correlated negatively with level of performance on measures of perceptual speed, working memory, episodic memory, and crystallized abilities. Partial set correlation analyses indicated that inconsistency predicted cognitive performance independent of level of performance. The results indicate that variability of performance is an important indicator of cognitive functioning and aging.

This article has been cited by other articles: (Search Google Scholar for Other Citing Articles)

				B. A. Shipley, G. Der, M. D. Taylor, and I. J. Deary Cognition and All-Cause Mortality Across the Entire Adult Age Range: Health and Lifestyle Survey Psychosom Med, January 1, 2006; 68(1): 17 - 24. [Abstract] [Full Text] [PDF]

				S. Robertson, J. Myerson, and S. Hale Are There Age Differences in Intraindividual Variability in Working Memory Performance? J. Gerontol. B. Psychol. Sci. Soc. Sci., January 1, 2006; 61(1): P18 - P24. [Abstract] [Full Text] [PDF]