Document Type
Article
Date
4-2015
Keywords
Symmetry, Perception, Visual, Spatial
Language
English
Disciplines
Behavioral Neurobiology | Cognition and Perception
Description/Abstract
The visual system is sensitive to symmetries in the frontoparallel plane, and bilateral symmetry about a vertical axis has a particular salience. However, these symmetries represent only a subset of the symmetries realizable in three-dimensional space. The retinal image symmetries formed when viewing natural objects are typically the projections of three-dimensional objects—animals, for example—that have a symmetry in depth. To characterize human sensitivity to depth symmetry, experiments measured observers’ ability to discriminate stereo displays that were symmetrically distributed in depth and those that were asymmetrically distributed. Disparity values were distributed about one of four planes passing through the z-axis and differing in frontoparallel orientation. Asymmetrical patterns were generated by perturbing one of these disparities. Symmetrical-asymmetrical discrimination thresholds were lowest for symmetry about the vertical plane and highest for the horizontal plane. Thresholds for discriminating repetitions and non-repetitions of depth values did not differ across the four planes, whereas discriminations for depth gradients differed from both the symmetry and repetition cases. The heightened sensitivity to symmetry in depth about the vertical plane is a 3-D analog of 2-D mirror-image symmetry performance and could be its source.
Recommended Citation
Farell, B. (2015). The perception of symmetry in depth: effect of symmetry plane orientation. Symmetry, 7, 336-353.
Source
http://www.mdpi.com/2073-8994/7/2/336
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
