Abstract
It is shown that human observers prefer images and artworks whose amplitude spectral slope is similar to that of natural scenes. It is also found that certain image spatial structure, such as symmetry, plays an important role in aesthetic preference. It is unclear whether and how these two factors interact on aesthetic preference. We investigated the effect of spectral slope and the number of symmetry axes on aesthetic preference. There were 30 types of images, with one of the 5 slopes (from −2 to 0 by a step of 0.5) and 6 symmetry levels (with 0, 1, 2, 4, 8 and 16 symmetry axes). The observers’ task was to rate aesthetic preference for these images on a 6-point Likert scale. In each trial, a test stimulus was presented at the center of the display and remained there until the observer made a response. Our results showed that there was main effect of spectral slope. The preference rating was an inverted-U shape function of spectral slope and peaked at slope = −1, consistent with previously reported results. There was also significant effect for the number of axes, with preference rating increased with the number of symmetry axes. Most importantly, there was interaction between the two factors. The non-symmetric patterns had little, if any, spectral slope effect while the symmetric patterns had a pronounced effect. The lack of spectral slope effect in the non-symmetric patterns implies that the scale-invariance effect on aesthetic preference may have been over-estimated in the previous research. The spatial structure, such as symmetry, may be more important than slope for aesthetic preference. The scale-invariance property, represented by spectral slope, is to modulate the spatial structure effect on preference ratings.
Acknowledgement: MOST 107-2410-H-431-007-MY2