title: Poggendorff rides again!
abstract: The Poggendorff illusion is one of the most exhaustively studied illusions. Can it be revived as an interesting problem? Perhaps by moving it to a slightly different domain. Here, we consider the occlusion of a subjectively linear ramp of tonal values. In a simple experiment, we find results closely resembling those of the geometrical Poggendorff. Yet, the "explanations" offered for the latter hardly apply to the former case. Depending upon one's perspective, this may be taken to "revive" the Poggendorff illusion.
authors.affiliation: Laboratory of Experimental Psychology, University of Leuven (KU Leuven), Leuven, Belgium, e-mail: vebjorn.ekroll@ppw.kuleuven.be.
authors.forename: Vebjørn
authors.initials: V
authors.lastname: Ekroll
authors.affiliation: Psychology Department, Rutgers University, Newark, NJ, USA, e-mail: alan@psychology.rutgers.edu.
authors.forename: Alan
authors.initials: A
authors.lastname: Gilchrist
authors.affiliation: Laboratory of Experimental Psychology, University of Leuven (KU Leuven), Leuven, Belgium; and Faculteit Sociale Wetenschappen, Psychologische Functieleer, Universiteit Utrecht, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands, e-mail: Jan.Koenderink@ppw.kuleuven.be.
authors.forename: Jan
authors.initials: J
authors.lastname: Koenderink
authors.affiliation: Faculteit Sociale Wetenschappen, Psychologische Functieleer, Universiteit Utrecht, Utrecht, The Netherlands, e-mail: andrea.vandoorn@telfort.nl.
authors.forename: Andrea
authors.initials: A
authors.lastname: van Doorn
authors.affiliation: Laboratory of Experimental Psychology, University of Leuven (KU Leuven), Leuven, Belgium, e-mail: Johan.Wagemans@psy.kuleuven.be.
authors.forename: Johan
authors.initials: J
authors.lastname: Wagemans
keywords: adjustment; illusion; luminance gradient; occlusion