title: Detection of symmetry and repetition in one and two objects. Structures versus strategies.
abstract: Symmetry is usually easier to detect within a single object than in two objects (one-object advantage), while the reverse is true for repetition (two-objects advantage). This interaction between regularity and number of objects could reflect an intrinsic property of encoding spatial relations within and across objects or it could reflect a matching strategy. To test this, regularities between two contours (belonging to a single object or two objects) had to be detected in two experiments. Projected three-dimensional (3-D) objects rotated in depth were used to disambiguate figure-ground segmentation and to make matching based on simple translations of the two-dimensional (2-D) contours unlikely. Experiment 1 showed the expected interaction between regularity and number of objects. Experiment 2 used two-objects displays only and prevented a matching strategy by also switching the positions of the two objects. Nevertheless, symmetry was never detected more easily than repetition in these two-objects displays. We conclude that structural coding, not matching strategies, underlies the one-object advantage for symmetry and the two-objects advantage for repetition.
authors.affiliation: University of Leuven, Belgium. arno.koning@nici.ru.nl
authors.forename: Arno
authors.initials: A
authors.lastname: Koning
authors.forename: Johan
authors.initials: J
authors.lastname: Wagemans
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention; D003867:Depth Perception; D004193:Discrimination Learning; D005260:Female; D005364:Field Dependence-Independence; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D009949:Orientation; D010364:Pattern Recognition, Visual; D011601:Psychophysics; D013028:Space Perception; D055815:Young Adult