title: Amodal completion in visual search: preemption or context effects?
abstract: In a previous study, search for a notched-disk target abutting a square among complete-disk nontargets and squares was inefficient in 250-ms exposures, but relatively efficient in 100-ms exposures. This finding was interpreted as evidence that amodal completion proceeds through a mosaic and then a completion stage, with the latter preempting the former. We used the same target but changed its context: Nontargets were instead notched disks near squares. Task set was also different: Participants searched for a complete disk. Contrary to the prediction of the preemption model, search was efficient in the 100-ms condition and inefficient in the 250-ms condition. We propose that in both the present and the previous studies, the target was ambiguous, and task set and context affected how it was perceived. In both experiments, set effects were evident for 100-ms exposures; context effects were evident for 250-ms exposures.
authors.affiliation: Department of Psychology, University of Arizona, Tucson 85721, USA. rauschen@u.arizona.edu
authors.forename: Robert
authors.initials: R
authors.lastname: Rauschenberger
authors.forename: Mary A
authors.initials: MA
authors.lastname: Peterson
authors.forename: Fauzia
authors.initials: F
authors.lastname: Mosca
authors.forename: Nicola
authors.initials: N
authors.lastname: Bruno
mesh_terms: D000339:Affect; D006801:Humans; D011930:Reaction Time; D014796:Visual Perception