Perspective-based illusory movement in a flat billboard-an explanation

Research output: Contribution to journalArticle


Colleges, School and Institutes


We describe a compelling motion illusion elicited by a huge billboard placed along a street, depicting a building that contains strong perspective cues. When observers move fast along the opposite sidewalk, they perceive the depicted building as rotating in their direction of travel. This is a special case of the 'following', or 'pointing out of the picture', illusion that elicits a strong illusory motion percept. Here we discuss the cause of the illusory motion and suggest that the brain relies on the depicted perspective cues to infer a 3-D shape and a concomitant motion that is incompatible with the physical pictorial surface.


Original languageEnglish
Pages (from-to)1086-1093
Number of pages8
Issue number8
Publication statusPublished - 1 Jan 2010