title: Search asymmetries: parallel processing of uncertain sensory information.
abstract: What is the mechanism underlying search phenomena such as search asymmetry? Two-stage models such as Feature Integration Theory and Guided Search propose parallel pre-attentive processing followed by serial post-attentive processing. They claim search asymmetry effects are indicative of finding pairs of features, one processed in parallel, the other in serial. An alternative proposal is that a 1-stage parallel process is responsible, and search asymmetries occur when one stimulus has greater internal uncertainty associated with it than another. While the latter account is simpler, only a few studies have set out to empirically test its quantitative predictions, and many researchers still subscribe to the 2-stage account. This paper examines three separate parallel models (Bayesian optimal observer, max rule, and a heuristic decision rule). All three parallel models can account for search asymmetry effects and I conclude that either people can optimally utilise the uncertain sensory data available to them, or are able to select heuristic decision rules which approximate optimal performance.
authors.affiliation: School of Psychology, University of Dundee, Park Place, Dundee DD1 4HN, United Kingdom. b.t.vincent@dundee.ac.uk
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Vincent
mesh_terms: D001288:Attention; D001499:Bayes Theorem; D001921:Brain / Q000502:physiology*; D006801:Humans; D008606:Mental Processes / Q000502:physiology*; D009949:Orientation / Q000502:physiology; D010775:Photic Stimulation; D011340:Problem Solving / Q000502:physiology; D012372:ROC Curve; D035501:Uncertainty; D014796:Visual Perception / Q000502:physiology