title: Information extraction from shadowed regions in images: an eye movement study.
abstract: Natural scenes often contain variations in local luminance as a result of cast shadows and illumination from different directions. When making judgments about such scenes, it may be hypothesized that darker regions (with lower relative contrast due to a lack of illumination) are avoided as they may provide less detailed information than well-illuminated areas. We here test this hypothesis, first by presenting participants images of faces that were digitally modified to simulate the effect of a shadow over half of the image, and second by presenting photographs of faces taken with side illumination, also resulting in the appearance of a shadow across half of the face. While participants viewed these images, they were asked to perform different tasks on the images, to allow for the presentation of the different versions of each image (left shadow, right shadow, no shadow), and to distract the observers from the contrast and illumination manipulations. The results confirm our hypothesis and demonstrate that observers fixate the better illuminated regions of the images.
authors.affiliation: School of Psychology, University of Aberdeen, UK; School of Psychology, University of Lincoln, UK.
authors.forename: Frouke
authors.initials: F
authors.lastname: Hermens
authors.affiliation: Department of Psychology, Faculty of Philosophy, University of Novi Sad, Serbia; Laboratory for experimental Psychology, Faculty of Philosophy, University of Belgrade, Serbia. Electronic address: szdravko@f.bg.ac.rs.
authors.forename: Sunčica
authors.initials: S
authors.lastname: Zdravković
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D005133:Eye Movements / Q000502:physiology*; D000066499:Facial Recognition / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D007600:Judgment; D008029:Lighting; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D055815:Young Adult
keywords: Eye movements; Lightness perception; Task effects