Orientation misperceptions induced by contrast polarity: comment on "Contrast polarities determine the direction of Café Wall tilts" by Akiyoshi Kitaoka, Baingio Pinna, and Gavin Brelstaff (2004).
According to Kitaoka et al (2004, Perception 33 11-20), the Café Wall illusion can be reduced to misalignment effects produced locally by a large shape on a line passing nearby. I demonstrate here that the interacting units are edges and not whole shapes, and that the source of the illusion does not consist in a local tilt but in a tendency of the edges to join when they have the same contrast polarity.
Roncato
Sergio
S
Dipartimento di Psicologia Generale, Università di Padova, via Venezia 8, 35131 Padua, Italy. sergio.roncato@unipd.it
D015350:Contrast Sensitivity / Q000502:physiology; D003463:Cues; D005556:Form Perception / Q000502:physiology; D006801:Humans; D009903:Optical Illusions / Q000502:physiology*; D009949:Orientation; D010469:Perceptual Distortion / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*