title: Illusory Visual Completion of an Object's Invisible Backside Can Make Your Finger Feel Shorter.
abstract: In a well-known magic trick known as multiplying balls, conjurers fool their audience with the use of a semi-spherical shell, which the audience perceives as a complete ball [1]. Here, we report that this illusion persists even when observers touch the inside of the shell with their own finger. Even more intriguingly, this also produces an illusion of bodily self-awareness in which the finger feels shorter, as if to make space for the purely illusory volume of the visually completed ball. This observation provides strong evidence for the controversial and counterintuitive idea that our experience of the hidden backsides of objects is shaped by genuine perceptual representations rather than mere cognitive guesswork or imagery [2].
authors.affiliation: Laboratory of Experimental Psychology, KU Leuven (University of Leuven), Tiensestraat 102, 3000 Leuven, Belgium. Electronic address: vebjorn.ekroll@ppw.kuleuven.be.
authors.forename: Vebjørn
authors.initials: V
authors.lastname: Ekroll
authors.affiliation: Laboratory of Experimental Psychology, KU Leuven (University of Leuven), Tiensestraat 102, 3000 Leuven, Belgium.
authors.forename: Bilge
authors.initials: B
authors.lastname: Sayim
authors.affiliation: Laboratory of Experimental Psychology, KU Leuven (University of Leuven), Tiensestraat 102, 3000 Leuven, Belgium.
authors.forename: Ruth
authors.initials: R
authors.lastname: Van der Hallen
authors.affiliation: Laboratory of Experimental Psychology, KU Leuven (University of Leuven), Tiensestraat 102, 3000 Leuven, Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: Wagemans
mesh_terms: D001828:Body Image; D005385:Fingers; D006801:Humans; D007088:Illusions; D013028:Space Perception; D055698:Touch Perception; D014796:Visual Perception / Q000502:physiology*