title: Perceptual organization in colour perception: Inverting the gamut expansion effect.
abstract: In the well-known gamut expansion effect, uniformly coloured target patches are perceived as more colourful when they are embedded in a uniform grey surround than when they are embedded in a variegated one. Here, we provide a demonstration showing that this effect can be inverted when the uniformly coloured target patches are replaced by variegated ones. This observation suggests that the gamut expansion effect is due to mechanisms of transparency perception rather than due to contrast adaptation.
authors.affiliation: Laboratory of Experimental Psychology, University of Leuven (KU Leuven), Tiensestraat 102, Box 3711, 3000 Leuven, Belgium; e-mail: vebjorn.ekroll@ppw.kuleuven.be.
authors.forename: Vebjørn
authors.initials: V
authors.lastname: Ekroll
authors.affiliation: Institute of Psychology, University of Kiel, Olshausenstr. 62, 24118 Kiel, Germany; e-mail: ffaul@psychologie.uni-kiel.de.
authors.forename: Franz
authors.initials: F
authors.lastname: Faul
keywords: colour scission; gamut expansion effect; perceptual organization; perceptual transparency; simultaneous colour contrast