Symmetry impedes symmetry discrimination

Symmetry impedes symmetry discrimination.

Objects in the world, natural and artificial alike, are often bilaterally symmetric. The visual system is likely to take advantage of this regularity to encode shapes for efficient object recognition. The nature of encoding a symmetric shape, and of encoding any departure from it, is therefore an important matter in visual perception. We addressed this issue of shape encoding empirically, notin...

Symmetry of Fullerene C_60

Grades of Discrimination: Indiscernibility, Symmetry, and Relativity

There are several relations which may fall short of genuine identity, but which behave like identity in important respects. Such grades of discrimination have recently been the subject of much philosophical and technical discussion. This paper aims to complete their technical investigation. Grades of indiscernibility are defined in terms of satisfaction of certain first-order formulas. Grades o...

Symmetry discrimination in patients with retinitis pigmentosa

To investigate the relative sensory and perceptual contributions to central visual function of patients with retinitis pigmentosa (RP), we tested symmetry discrimination using block patterns with varying types of symmetric organization. Eleven control subjects with normal vision and 11 patients with RP with 20/30 visual acuity or better, viewed patterns presented for 255 msec. The patterns diff...

Lie symmetry analysis for Kawahara-KdV equations

We introduce a new solution for Kawahara-KdV equations. The Lie group analysis is used to carry out the integration of this equations. The similarity reductions and exact solutions are obtained based on the optimal system method.