Does shading affect size illusions in simple line drawings?
” Perception 33 ECVP Abstract Supplement Does shading affect size illusions in simple line drawings? J M Zanker, A-al-J Kane Abdullah Geometric illusions can be observed in a number of simple line drawings like the Müller-Lyer or Judd figures. Perspective explanations, such as the ‘inappropriate constancy scaling’ theory, advocate that the size of line drawing components may be adjusted by the perceptual system with reference to the inferred three-dimensional structure of the pictured object. This theory would predict that additional depth cues, for instance shading added to line drawings, should affect these illusions by manipulating the three-dimensional appearance. We measured the magnitude of length misjudgments for horizontal Müller-Lyer and Judd figures in the pure line drawings, and with shading attached to the top or bottom of the figures, which are interpreted as ‘folded’ configurations with a horizontal edge behind or in front of the image plane, respectively. While we could
