August 2009
Volume 9, Issue 8
Free
Vision Sciences Society Annual Meeting Abstract  |   August 2009
The effects of aging on contrast discrimination
Author Affiliations
  • Christopher M. Fiacconi
    Department of Psychology, Neuroscience, & Behaviour, McMaster University
  • Allison B. Sekuler
    Department of Psychology, Neuroscience, & Behaviour, McMaster University
  • Patrick J. Bennett
    Department of Psychology, Neuroscience, & Behaviour, McMaster University
Journal of Vision August 2009, Vol.9, 1073. doi:10.1167/9.8.1073
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Christopher M. Fiacconi, Allison B. Sekuler, Patrick J. Bennett; The effects of aging on contrast discrimination. Journal of Vision 2009;9(8):1073. doi: 10.1167/9.8.1073.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Abstract

It is well established that contrast sensitivity for sine wave gratings is reduced in older observers, but comparatively little is known about how aging affects the perception of supra-threshold contrast. The current experiments therefore examined contrast discrimination in groups of younger (n=11; mean age = 23 years) and older (n=12; mean age = 69 years) observers. In experiment one, the target — a horizontal 1.5 c/deg Gabor pattern — was added to a mask grating of the same spatial frequency, orientation, and spatial phase. Threshold-vs-contrast (TvC) curves were obtained by measuring detection thresholds for the target as a function of mask contrast, which ranged from zero to 0.32. As was reported by Beard et al. (1994), TvC curves had similar dipper shapes in both age groups. Contrast discrimination thresholds were higher in older observers, but the age differences were reduced greatly after discrimination thresholds were normalized by dividing them by detection thresholds (i.e., thresholds measured with a zero contrast mask). In a second experiment, TvC curves were measured using a vertically-oriented mask. As expected, using a mask that was orthogonal to the target significantly altered the shapes of the TvC curves, which were nearly flat and increased slightly only at the highest mask contrast. Contrast discrimination thresholds were higher in older observers, but, as was found in the first experiment, age differences were eliminated by normalizing discriminating thresholds by detection thresholds. Hence the results from both experiments suggest age differences in supra-threshold contrast discrimination can be explained by age differences in contrast sensitivity.

Fiacconi, C. M. Sekuler, A. B. Bennett, P. J. (2009). The effects of aging on contrast discrimination [Abstract]. Journal of Vision, 9(8):1073, 1073a, http://journalofvision.org/9/8/1073/, doi:10.1167/9.8.1073. [CrossRef]
Footnotes
 This research is supported by grants from the Canada Research Chair Program and CIHR.
Footnotes
 Donna Waxman.
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×