Rapid figure-ground responses to stereograms reveal an advantage for a convex foreground.
Convexity has long been recognised as a factor that affects figure - ground segmentation, even when pitted against other factors such as symmetry [Kanizsa and Gerbino, 1976 Art and Artefacts Ed.M Henle (New York: Springer) pp 25-32]. It is accepted in the literature that the difference between concave and convex contours is important for the visual system, and that there is a prior expectation favouring convexities as figure. We used bipartite stimuli and a simple task in which observers had to report whether the foreground was on the left or the right. We report objective evidence that supports the idea that convexity affects figure-ground assignment, even though our stimuli were not pictorial in that depth order was specified unambiguously by binocular disparity.
School of Psychology, University of Liverpool, UK. M.Bertamini@liverpool.ac.uk
Marco
M
Bertamini
Rebecca
R
Lawson
D000704:Analysis of Variance; D003867:Depth Perception / Q000502:physiology; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D009903:Optical Illusions; D011601:Psychophysics; D011930:Reaction Time; D015348:Vision, Binocular / Q000502:physiology*