title: Local and global orientation in visual search.
abstract: Six experiments investigated the role of global (shape) and local (contour) orientation in visual search for an orientation target. Experiment 1 demonstrated that search for a conjunction of local contours with a distinct global orientation was less efficient than search for a target featurally distinct in terms of both global and local contour orientation. However, Experiments 2 and 4 demonstrated that the presence of a unique line contour was neither sufficient nor necessary to allow efficient search. Experiment 5 found that search for a local orientation difference was strongly impeded by irrelevant variation in global orientation, arguing for a preeminent role for global orientation. Finally, Experiment 6 demonstrated that the orientation search asymmetry holds for the global orientation of stimuli. Taken together, the results are consistent with visual search processes guided predominantly by a representation of global orientation.
authors.affiliation: Department of Psychology, Birkbeck College University of London, England. a.found@psychology.bbk.ac.uk
authors.forename: A
authors.initials: A
authors.lastname: Found
authors.forename: H J
authors.initials: HJ
authors.lastname: Müller
mesh_terms: D000328:Adult; D006801:Humans; D009949:Orientation; D011930:Reaction Time; D014796:Visual Perception