title: Gaze in Visual Search Is Guided More Efficiently by Positive Cues than by Negative Cues.
abstract: Visual search can be accelerated when properties of the target are known. Such knowledge allows the searcher to direct attention to items sharing these properties. Recent work indicates that information about properties of non-targets (i.e., negative cues) can also guide search. In the present study, we examine whether negative cues lead to different search behavior compared to positive cues. We asked observers to search for a target defined by a certain shape singleton (broken line among solid lines). Each line was embedded in a colored disk. In "positive cue" blocks, participants were informed about possible colors of the target item. In "negative cue" blocks, the participants were informed about colors that could not contain the target. Search displays were designed such that with both the positive and negative cues, the same number of items could potentially contain the broken line ("relevant items"). Thus, both cues were equally informative. We measured response times and eye movements. Participants exhibited longer response times when provided with negative cues compared to positive cues. Although negative cues did guide the eyes to relevant items, there were marked differences in eye movements. Negative cues resulted in smaller proportions of fixations on relevant items, longer duration of fixations and in higher rates of fixations per item as compared to positive cues. The effectiveness of both cue types, as measured by fixations on relevant items, increased over the course of each search. In sum, a negative color cue can guide attention to relevant items, but it is less efficient than a positive cue of the same informational value.
authors.affiliation: Institute of Clinical Neurosciences, University of Munich, Munich, Germany.|German Center for Vertigo and Balance Disorders, University of Munich, Munich, Germany.
authors.forename: Günter
authors.initials: G
authors.lastname: Kugler
authors.affiliation: Neurophysics, Philipps University Marburg, Marburg, Germany.|Centre for Vision Research, York University, Toronto, Ontario, Canada.
authors.forename: Bernard Marius
authors.initials: BM
authors.lastname: 't Hart
authors.affiliation: Institute of Clinical Neurosciences, University of Munich, Munich, Germany.|German Center for Vertigo and Balance Disorders, University of Munich, Munich, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Kohlbecher
authors.affiliation: Neurophysics, Philipps University Marburg, Marburg, Germany.|Institute of Physics, Chemnitz University of Technology, Chemnitz, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Einhäuser
authors.affiliation: Institute of Medical Technology, Brandenburg University of Technology Cottbus-Senftenberg, Senftenberg, Germany.
authors.forename: Erich
authors.initials: E
authors.lastname: Schneider
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003463:Cues; D005133:Eye Movements; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011930:Reaction Time; D055815:Young Adult