May 2008
Volume 8, Issue 6
Free
Vision Sciences Society Annual Meeting Abstract  |   May 2008
Size and shape-frequency after-effects: same or different mechanism?
Author Affiliations
  • Elena Gheorghiu
    McGill Vision Research, Department of Ophthalmology, McGill University, 687 Pine Avenue W., Montreal H3A 1A1, Quebec, Canada
  • Frederick A. A. Kingdom
    McGill Vision Research, Department of Ophthalmology, McGill University, 687 Pine Avenue W., Montreal H3A 1A1, Quebec, Canada
  • Emma Witney
    McGill Vision Research, Department of Ophthalmology, McGill University, 687 Pine Avenue W., Montreal H3A 1A1, Quebec, Canada
Journal of Vision May 2008, Vol.8, 936. doi:10.1167/8.6.936
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Elena Gheorghiu, Frederick A. A. Kingdom, Emma Witney; Size and shape-frequency after-effects: same or different mechanism?. Journal of Vision 2008;8(6):936. doi: 10.1167/8.6.936.

      Download citation file:


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

      ×
  • Supplements
Abstract

Aim. The size, or luminance spatial frequency after-effect (LFAE) is the phenomenon in which adaptation to a luminance grating of given spatial frequency causes a shift in the perceived spatial frequency of a grating away from that of the adapting grating (Blakemore & Sutton, 1969, Science, 166, 245–7).The analogous shape-frequency after-effect (or SFAE) is the phenomenon in which adaptation to a sine-wave-shaped contour causes a shift in the apparent shape-frequency of a test contour away from that of the adapting stimulus (Gheorghiu & Kingdom, 2007, Vis.Res., 47, 834–44). It is widely believed that the LFAE is mediated by luminance-spatial-frequency-selective channels, while it has been suggested that the SFAE is mediated by curvature-selective channels. However it is possible that the SFAE is mediated by the same mechanism as underlies the LFAE, in spite of the fact that the stimuli involved have little Fourier energy in common. Methods. We measured both SFAEs and LFAEs using a conventional staircase procedure. The contour-shape stimuli were sine-wave-shaped contours and edges; luminance stimuli were sine-wave, square-wave and line luminance gratings. The rationale was that if the after-effects were reduced when adaptor and test stimuli were of a different class (shape versus luminance), this suggested that the SFAE and LFAE were mediated by different mechanisms. Results. While similar-sized after-effects were found for same-class adaptor-and-test stimuli (either shape or luminance), the after-effects were greatly reduced for different-class adaptor-and-test stimuli (shape adaptors and luminance tests, or vice-versa). Conclusion. SFAEs are mediated by different mechanisms to the LFAE.

Gheorghiu, E. Kingdom, F. A. A. Witney, E. (2008). Size and shape-frequency after-effects: same or different mechanism? [Abstract]. Journal of Vision, 8(6):936, 936a, http://journalofvision.org/8/6/936/, doi:10.1167/8.6.936. [CrossRef]
Footnotes
 This research was supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) grant # OGP01217130 given to F.K.
×
×

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.

×