Complexity Reduction Explains Preference to Symmetric Patterns

Symmetric patterns are more appealing to human observers than asymmetric ones. Here, we investigated the possible mechanisms underlying such preference. All Stimuli were derived from phase scrambled versions of forty face or nature images. There were four types of test images: symmetry, in which one part of the image was the reflective transform of the other part about an axis; repetition, one part of the image was a copy of the other part; anti-symmetry, similar to symmetry but the contrast of one side was reversed; and interleaved patterns, half of the symmetric pattern was replaced by a scrambled image. The number of axes ranged from 1 to 16 for all image types. The task of our 20 observers was to give a preference rating to each image on a 6-point Lickert Scale. The preference rating increased with the number of axis for all stimulus type. The preference to symmetry was similar to that to repetition and was slightly better than anti-symmetry. The preference to interleaved pattern was much less than other types of stimuli. The preference rating of an image has little correlation with the slope of the power spectrum but of the image but is inversely correlated with its complexity.