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 Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Thorvaldsson, V. Articles by Johansson, B. Search for Related Content PubMed PubMed Citation Articles by Thorvaldsson, V. Articles by Johansson, B.

Effects of Repeated Testing in a Longitudinal Age-Homogeneous Study of Cognitive Aging

¹ Department of Psychology, Göteborg University, Sweden.
² Department of Human Development and Family Studies, Pennsylvania State University, University Park.
³ Institute of Gerontology, Jönköping University, Sweden.

Address correspondence to Boo Johansson, Department of Psychology, Göteborg University, Box 500, SE- 405 30 Göteborg, Sweden. E-mail: Boo.Johansson{at}psy.gu.se

Estimates of gains related to repeated test exposure (retest effects) and within-person cognitive changes are confounded in most longitudinal studies because of the nonindependent time structures underlying both processes. Recently developed statistical approaches rely on between-person age differences to estimate effects of repeated testing. This study, however, demonstrates how retest effects can be evaluated at the group level in an age-homogeneous population-based study by use of a sampling-based design approach in which level and change of cognitive performance of previous participants, measured at ages 70, 75, 79, 81, 85, 88, 90, 92, 95, 97, and 99 years, were compared with performances of survivors of a representative sample identified and drawn from the same original population cohort but invited for the first time at age 85 with subsequent measurements at ages 88, 90, 92, 95, 97, and 99. The comparisons revealed a trend toward retest effects on two out of five cognitive measurements. The study demonstrates how a design-based approach can provide valuable insights into continuous learning processes embedded in population average aging trajectories that are not confounded with cohort and mortality-related selective attrition.

This article has been cited by other articles:

				V. Thorvaldsson, S. M. Hofer, S. Berg, I. Skoog, S. Sacuiu, and B. Johansson Onset of terminal decline in cognitive abilities in individuals without dementia Neurology, September 16, 2008; 71(12): 882 - 887. [Abstract] [Full Text] [PDF]