title: Competitive guided search: meeting the challenge of benchmark RT distributions.
abstract: Historically, visual search models were mainly evaluated based on their account of mean reaction times (RTs) and accuracy data. More recently, Wolfe, Palmer, and Horowitz (2010) have demonstrated that the shape of the entire RT distributions imposes important constraints on visual search theories and can falsify even successful models such as guided search, raising a challenge to computational theories of search. Competitive guided search is a novel model that meets this important challenge. The model is an adaptation of guided search, featuring a series of item selection and identification iterations with guidance towards targets. The main novelty of the model is its termination rule: A quit unit, which aborts the search upon selection, competes with items for selection and is inhibited by the saliency map of the visual display. As the trial proceeds, the quit unit both increases in strength and suffers less saliency-based inhibition and hence the conditional probability of quitting the trial accelerates. The model is fitted to data the data from three classical search task that have been traditionally considered to be governed by qualitatively different mechanisms, including a spatial configuration, a conjunction, and a feature search (Wolfe et al., 2010). The model is mathematically tractable and it accounts for the properties of RT distributions and for error rates in all three search tasks, providing a unifying theoretical framework for visual search.
authors.affiliation: School of Psychological Sciences, Tel Aviv University, Ramat Aviv, Israel. ranimora@post.tau.ac.il
authors.forename: Rani
authors.initials: R
authors.lastname: Moran
authors.forename: Michael
authors.initials: M
authors.lastname: Zehetleitner
authors.forename: Hermann J
authors.initials: HJ
authors.lastname: Müller
authors.forename: Marius
authors.initials: M
authors.lastname: Usher
mesh_terms: D000222:Adaptation, Physiological; D003198:Computer Simulation; D006801:Humans; D011336:Probability; D011930:Reaction Time / Q000502:physiology*; D017603:Signal Detection, Psychological / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
keywords: RT distributions; computational modeling; guided search; parallel versus serial search; salience; search termination; sequential sampling