title: Altering Mueller-Lyer illusion magnitude using figural additions at the wing-shaft intersections.
abstract: The Mueller-Lyer (ML) illusion has been used to study the way in which perceived length is affected by processes of information extraction when a visual target of interest (the ML shaft) is surrounded by other nontarget figural elements (inward-or outward-turning wings). It is argued that the perception of length is computed in terms of the center of gravity or centroid of figural elements at the wing-shaft intersection. The outward-turning wings shift the computational centroid away from the shaft end, giving rise to an erroneous overestimation of shaft length, while the inward-turning wings have the opposite effect. In three experiments, we observed that figural changes, which theoretically shifted the center of gravity of figural elements at the wing-shaft intersection, also increased or decreased the magnitude of the ML illusion.
authors.affiliation: Department of Psychology, St. Lawrence University, Canton, NY 13617, USA. asearleman@stlawu.edu
authors.forename: Alan
authors.initials: A
authors.lastname: Searleman
authors.forename: Clare
authors.initials: C
authors.lastname: Porac
authors.forename: Colette
authors.initials: C
authors.lastname: Dafoe
authors.forename: Brian
authors.initials: B
authors.lastname: Hetzel
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D006801:Humans; D009903:Optical Illusions; D011582:Psychological Theory; D012858:Size Perception