Mondrian, eye movements, and the oblique effect.

Observers prefer Mondrian's paintings in their original orientation compared to when rotated--"the oblique effect" (Latto et al, 2000 Perception 29 981-987). We tested whether eye movements could provide any insight into this aesthetic bias. While recording fixation duration and saccade length, we presented eight Mondrian paintings dated 1921-1944 on a CRT in either their original or seven rotated positions to ten observers who used a Likert scale to report how (dis)pleasing they found each image. We report on eye-movement patterns from nine pairs of images that had a significant orientation effect. During the 20 s scans, fixation durations increased linearly, more so for pleasing images than for non-pleasing images. Moreover, saccade distances oscillated over the viewing interval, with larger saccade-distance oscillations for the pleasing images than the non-pleasing images. Both of these findings agree with earlier work by Nodine et al (1993 Leonardo 26 219-227), and confirm that as an abstract painting becomes more aesthetically pleasing, it shows both a greater amount of diversive/specific types of image exploration and balance. Thus, any increase in visual fluency in localizing vertical and horizontal versus oblique lines can lead to an increase in the aesthetic pleasure of viewing Mondrian's work.