ABSTRACT
This chapter explains to test for the presence or absence of a symmetry effect in parallel lines with a greatly expanded data base and to perform a similar test with a different stimulus set composed of regular and asymmetrical snowflake-like patterns. Gestalt, information theory, and autocorrelation models of form perception all predict that pattern recognition should be enhanced by increases in the degree of symmetry of visual stimuli. However, in one of the experiments reported in a recent monograph, symmetry of line spacing was found to have a negligible effect in a target-detection task in which dotted forms had to be extracted from dotted visual-noise fields. When the number of dots in his patterns remained constant, however, then symmetry had a strong effect in both recall and reproduction tasks. Target stimulus patterns were prepared in advance by the experimenter and then stored in the computer for recall as requested by the experimental control program.
