Perceived symmetry and visual matching.

The effects of perceived symmetry on physical-matching latency was evaluated. The stimuli were letter pairs made from the letters F, G, J, L. and R in either normal, reversed, or inverted orientations. When the same letter was used twice to form a pair, the different orientation-combinations produced four types of symmetry: rotational, vertical-axis bilateral, and translational symmetry, as well as a distorted version of horizontal-axis bilateral symmetry. Perceptual organization in the form of symmetry inhibited physical matching.