This Article Full Text Full Text (PDF) Services Download to citation manager PubMed PubMed Citation

Aging and Bilateral Symmetry Detection

^a Department of Psychology, University of North Texas, Denton
^b Sir Mortimer B. Davis Jewish General Hospital, McGill University, Montreal, Canada
^c School of Optometry, University of Montreal, Canada

Andrew M. Herbert, University of North Texas, Department of Psychology, P.O. Box 311280, Denton, TX 76203-1280 E-mail: herberta{at}unt.edu.

Decision Editor: Margie E. Lachman, PhD

The salience of bilateral symmetry varies as a function of the orientation of the symmetry axis. Vertical symmetry is most salient, followed by horizontal and then oblique orientations. We tested symmetry detection in different age groups to determine whether performance of this intermediate-level visual task is affected by normal, nonpathological aging. We tested forty participants and analyzed the results with respect to age group and symmetry orientation (vertical, horizontal, and 45 degree oblique). There was a vertical symmetry detection advantage for all participants, where sensitivity was highest for vertical symmetry, followed by horizontal symmetry, and then the oblique symmetry. Sensitivity to symmetry did not differ for the two younger age groups (aged 19–39 and 40–60), but declined significantly for the group aged 61–70, and declined again for the oldest group aged 71–80. This age-related difference in sensitivity to symmetry was not reflected in a measure of bias, where there were no differences as a function of age.