title: Lightness perception for surfaces moving through different illumination levels.
abstract: Lightness perception has mainly been studied with static scenes so far. This study presents four experiments investigating lightness perception under dynamic illumination conditions. We asked participants for lightness matches of a virtual three-dimensional target moving through a light field while their eye movements were recorded. We found that the target appeared differently, depending on the direction of motion in the light field and its precise position in the light field. Lightness was also strongly affected by the choice of fixation positions with the spatiotemporal image sequence. Overall, lightness constancy was improved when observers could freely view the object, over when they were forced to fixate certain regions. Our results show that dynamic scenes and nonuniform light fields are particularly challenging for our visual system. Eye movements in such scenarios are chosen to improve lightness constancy.
authors.affiliation: Abteilung Allgemeine Psychologie, Justus-Liebig-Universität Giessen, Giessen, Germanymatteo.toscani@psychol.uni-giessen.de.
authors.forename: Matteo
authors.initials: M
authors.lastname: Toscani
authors.affiliation: Department of Psychology, Faculty of Philosophy, University of Novi Sad, Novi Sad, SerbiaLaboratory for Experimental Psychology, Faculty of Philosophy, University of Belgrade, Belgrade, Serbia.
authors.forename: Suncica
authors.initials: S
authors.lastname: Zdravkovic
authors.affiliation: Abteilung Allgemeine Psychologie, Justus-Liebig-Universität Giessen, Giessen, Germany.
authors.forename: Karl R
authors.initials: KR
authors.lastname: Gegenfurtner
mesh_terms: D015350:Contrast Sensitivity / Q000502:physiology*; D005133:Eye Movements; D006801:Humans; D008027:Light; D008029:Lighting; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D014796:Visual Perception