Abstract
Symmetry is a complex image property that is exploited by a sufficiently wide range of species to indicate that it is detected using simple visual mechanisms. These mechanisms rely on measurements made close to the axis of symmetry. We investigated the size and shape of this integration region (IR) by measuring human detection of spatially band-pass symmetrical patches embedded in noise. Resistance to disruption of symmetry (in the form of random phase noise) improves with increasing patch size, and then asymptotes when the embedded region fills the IR. The size of the IR is shown to vary in inverse proportion to spatial frequency; i.e. symmetry detection exhibits scale invariance. The IR is shown to have rigid dimensions, elongated in the direction of the axis of symmetry, with an aspect ratio of ca. 2:1. These results are consistent with a central role for spatial filtering in symmetry detection.
Full Text
The Full Text of this article is available as a PDF (194.6 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Barlow H. B., Reeves B. C. The versatility and absolute efficiency of detecting mirror symmetry in random dot displays. Vision Res. 1979;19(7):783–793. doi: 10.1016/0042-6989(79)90154-8. [DOI] [PubMed] [Google Scholar]
- Dakin S. C., Hess R. F. The spatial mechanisms mediating symmetry perception. Vision Res. 1997 Oct;37(20):2915–2930. doi: 10.1016/s0042-6989(97)00031-x. [DOI] [PubMed] [Google Scholar]
- Dakin S. C., Watt R. J. Detection of bilateral symmetry using spatial filters. Spat Vis. 1994;8(4):393–413. doi: 10.1163/156856894x00071. [DOI] [PubMed] [Google Scholar]
- Fisher C. B., Bornstein M. H. Identification of symmetry: effects of stimulus orientation and head position. Percept Psychophys. 1982 Nov;32(5):443–448. doi: 10.3758/bf03202774. [DOI] [PubMed] [Google Scholar]
- Grammer K., Thornhill R. Human (Homo sapiens) facial attractiveness and sexual selection: the role of symmetry and averageness. J Comp Psychol. 1994 Sep;108(3):233–242. doi: 10.1037/0735-7036.108.3.233. [DOI] [PubMed] [Google Scholar]
- Julesz B. Experiments in the visual perception of texture. Sci Am. 1975 Apr;232(4):34–43. doi: 10.1038/scientificamerican0475-34. [DOI] [PubMed] [Google Scholar]
- Labonté F., Shapira Y., Cohen P., Faubert J. A model for global symmetry detection in dense images. Spat Vis. 1995;9(1):33–55. doi: 10.1163/156856895x00106. [DOI] [PubMed] [Google Scholar]
- MADDESS T., YANG E. -C. Orientation-sensitive Neurons in the Brain of the Honey Bee (Apis mellifera). J Insect Physiol. 1997 Apr;43(4):329–336. doi: 10.1016/s0022-1910(96)00111-4. [DOI] [PubMed] [Google Scholar]
- Marr D., Hildreth E. Theory of edge detection. Proc R Soc Lond B Biol Sci. 1980 Feb 29;207(1167):187–217. doi: 10.1098/rspb.1980.0020. [DOI] [PubMed] [Google Scholar]
- Møller A. P. Bumblebee preference for symmetrical flowers. Proc Natl Acad Sci U S A. 1995 Mar 14;92(6):2288–2292. doi: 10.1073/pnas.92.6.2288. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Møller A. P. Female swallow preference for symmetrical male sexual ornaments. Nature. 1992 May 21;357(6375):238–240. doi: 10.1038/357238a0. [DOI] [PubMed] [Google Scholar]
- Pelli D. G. The VideoToolbox software for visual psychophysics: transforming numbers into movies. Spat Vis. 1997;10(4):437–442. [PubMed] [Google Scholar]
- Tyler C. W., Hardage L., Miller R. T. Multiple mechanisms for the detection of mirror symmetry. Spat Vis. 1995;9(1):79–100. doi: 10.1163/156856895x00124. [DOI] [PubMed] [Google Scholar]
- Wenderoth P. The effects of the contrast polarity of dot-pair partners on the detection of bilateral symmetry. Perception. 1996;25(7):757–771. doi: 10.1068/p250757. [DOI] [PubMed] [Google Scholar]
- Wenderoth P. The role of pattern outline in bilateral symmetry detection with briefly flashed dot patterns. Spat Vis. 1995;9(1):57–77. doi: 10.1163/156856895x00115. [DOI] [PubMed] [Google Scholar]