First-order structure induces the 3-D curvature contrast effect.
A 3-D curvature contrast effect has been reported in shading-and-texture-defined (Curran & Johnson (1996). Vision Research 36, 3641-3653) and in stereoscopically defined (te Pas, Rogers, & Ledgeway (2000). Current Psychology Letters: Brain, Behaviour and Cognition 1, 117-126) stimuli. Our experiments show that a clear 3-D curvature contrast effect also occurs in motion-defined stimuli. The magnitude of the effect is similar in motion-, stereo- and shading-and-texture defined stimuli, suggesting that the 3-D curvature contrast effect is shape-based. We find a distinct contrast effect that is similar in the case of inducers that contain second-order (curvature) information and in the case of inducers that contain only first-order (slant and tilt) information. The effect with inducers that contain only zeroth-order (depth) information is very small. We conclude that the first-order structure is sufficient to induce a 3-D contrast effect.
te Pas
S F
SF
Psychonomics, Helmholtz Instituut, Universiteit Utrecht, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands. s.tepas@fss.uu.nl
Kappers
A M
AM
D003867:Depth Perception / Q000502:physiology*; D004056:Differential Threshold; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D009039:Motion Perception / Q000502:physiology*; D011594:Psychometrics