September 2017
Volume 17, Issue 10
Open Access
Vision Sciences Society Annual Meeting Abstract  |   August 2017
The perceptual advantage of symmetry for scene perception
Author Affiliations
  • John Wilder
    Department of Computer Science, University of Toronto
  • Morteza Rezanejad
    Centre for Intelligent Machines and School of Computer Science, McGill University
  • Sven Dickinson
    Department of Computer Science, University of Toronto
  • Kaleem Siddiqi
    Centre for Intelligent Machines and School of Computer Science, McGill University
  • Allan Jepson
    Department of Computer Science, University of Toronto
  • Dirk Walther
    Department of Psychology, University of Toronto
Journal of Vision August 2017, Vol.17, 1091. doi:10.1167/17.10.1091
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      John Wilder, Morteza Rezanejad, Sven Dickinson, Kaleem Siddiqi, Allan Jepson, Dirk Walther; The perceptual advantage of symmetry for scene perception. Journal of Vision 2017;17(10):1091. doi: 10.1167/17.10.1091.

      Download citation file:


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

      ×
  • Supplements
Abstract

As one of the original Gestalt principles, symmetry is believed to support visual perception by aiding the visual system in detecting objects, which tend to be symmetric. Whereas the role of symmetry for the perception of isolated objects has been well studied, it is so far unknown what role symmetry plays in the perception of cluttered, real-world scenes. We demonstrate, for the first time, a strong perceptual advantage of local contour symmetry for perceiving complex real-world scenes. Unlike global symmetry, local symmetry is largely invariant to pose. Scenes were represented as line drawings, which have been shown to capture essential structural information required for successful scene categorization (Walther et al., 2011). We assessed local symmetry by computing the degree to which contour pixels participate in non-accidental symmetry relationships in the scene, using the medial axis transform (Blum, 1973; Siddiqi et al, 2008). Each contour pixel was assigned a numerical symmetry value based on the rate of change of the radius function of the medial branch to which it was assigned. We then generated two alternate versions of each line drawing, one with the half of the pixels ranked most symmetric and one with the half ranked least symmetric. The two types of modified line drawings were shown to twelve participants along with intact line drawings in a six-alternative forced-choice scene categorization experiment with short presentations (53 ms), followed by a perceptual mask. Each participant saw 20 images from each category, per condition (360 total trials). Participants' categorization accuracy was significantly higher for the most symmetric contours (49.7%) than for the least symmetric contours (38.2%), with intact contours showing higher performance than both modified conditions (65.8%). These results demonstrate, for the first time, the role of local contour symmetry as a crucial organizing principle in complex real-world scenes.

Meeting abstract presented at VSS 2017

×
×

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.

×