When complex is easy on the mind: Internal repetition of visual information in complex objects is a source of perceptual fluency.

Across 3 studies, we investigated whether visual complexity deriving from internally repeating visual information over many scale levels is a source of perceptual fluency. Such continuous repetition of visual information is formalized in fractal geometry and is a key-property of natural structures. In the first 2 studies, we exposed participants to 3-dimensional high-fractal versus low-fractal stimuli, respectively characterized by a relatively high versus low degree of internal repetition of visual information. Participants evaluated high-fractal stimuli as more complex and fascinating than their low-fractal counterparts. We assessed ease of processing by asking participants to solve effortful puzzles during and after exposure to high-fractal versus low-fractal stimuli. Across both studies, we found that puzzles presented during and after seeing high-fractal stimuli were perceived as the easiest ones to solve and were solved more accurately and faster than puzzles associated with the low-fractal stimuli. In Study 3, we ran the Dot Probe Procedure to rule out that the findings from Study 1 and Study 2 reflected differences in attentional bias between the high-fractal and low-fractal stimuli, rather than perceptual fluency. Overall, our findings confirm that complexity deriving from internal repetition of visual information can be easy on the mind. (c) 2015 APA, all rights reserved).