title: Angle illusion in a straight road.
abstract: We report a new angle illusion observed when viewing a real scene involving a straight road. The scene portrays two white lines which outline a traffic lane on a road and converge to a vanishing point. In experiment 1, observers estimated the angle created by these converging lines in this scene or in its image projected onto a screen. Results showed strong underestimation of the angle, ie over 50% for observations of both the real scene and its projected image. Experiment 2 assessed how depth cues in projected images influence the angle illusion. Results showed that this angle illusion disappeared when scene information surrounding convergent lines was removed. In addition, the illusion was attenuated with projection of an inverted scene image. These findings are interpreted in terms of a misadoption of depth information in the processing of angle perception in a flat image; in turn, this induces a massive angle illusion.
authors.affiliation: Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube-shi, Yamaguchi 755-8611, Japan. osaa@yamaguchi-u.ac.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Osa
authors.forename: Kazumi
authors.initials: K
authors.lastname: Nagata
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Honda
authors.forename: Makoto
authors.initials: M
authors.lastname: Ichikawa
authors.forename: Ken
authors.initials: K
authors.lastname: Matsuda
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Miike
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D003867:Depth Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009903:Optical Illusions / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation; D014796:Visual Perception / Q000502:physiology*