Partial orientation pop-out helps difficult search for orientation

Abstract

Weinterrupted pop-out search before it produced a detection response by adding extra distractors to the search display. Weshow that when pop-out for an orientation target fails because of this interruption, it nevertheless provides useful information to the processes responsible for difficult search. That is, partial pop-out assists difficult search. This interaction has also been found for color stimuli (Olds, Cowan, & Jolicoeur, 2000a, 2000b. These results indicate that interactions and/or overlap between the mechanisms responsible for pop-out and the mechanisms responsible for difficult search may be quite general in early visual selection.Vision provides people with an enormous amount of information. Because it is impossible to process all ofthis information in detail, limited subsets must be quickly selected for further analysis. How is this selection performed? The mechanisms responsible for visual selection can be elucidated by data from search tasks. In a search task, observers determine whether or not a target appears among distractors (other items) in a complex display. Researchers classify search performance in terms of response time (RT) patterns. In pop-out search, RTs are fast, and RT for correct responses is virtually independent of the number of items in the display. In difficult search, RTs are much longer and generally increase linearly with the number of items (Treisman & Gelade, 1980). Pop-out search is possible for some target-distractor relationships but not others. Many researchers believe that early "preattentive" mechanisms in the brain perform pop-out search in parallel across the entire display; difficult search occurs when these mechanisms cannot detect the target and "attention" is required (Treisman & Gelade, 1980;Wolfe, 1994). Most work on attention implicitly assumes that preattentive processing is all-or-nothing (Treisman & Gelade, 1980;Wolfe, 1994), despite suggestions that processing could develop gradually (e.g., Wolfe, 1994, p. 229; Wolfe, Cave, & Franzel, 1989, p. 428).Olds, Jolicceur (2000a, 2000b) have shown, however, that pre attentive processing of color is not allor-nothing but can, in fact, be dissected both temporally and spatially. They interrupted pop-out search at interme- diate points in processing, and the results showed that even when pop-out search fails, its partially completed computations can be used to assist other, slower search processes. The results of these experiments provide basic constraints that must be satisfied by any model of early vision and visual selection. Because all visual processing is affected by which portions ofthe visual field these early mechanisms select for further analysis, it is important to determine the nature ofeach selection mechanism, as well as interactions between the mechanisms.All of the results of Olds et al. (2000aOlds et al. ( , 2000b were based on experiments in the color domain. Are the results specific to color, or can they be generalized to other stimulus dimensions? In this paper, we investigate interactions be...

Reference Production as Search: The Impact of Domain Size on the Production of Distinguishing Descriptions

“…Friedman‐Hill & Wolfe, ). Guidance (Olds, Cowan, & Jolicoeur, ,b,c) or preview of features in a target conjunction (Olds & Fockler, ) also facilitates search for complex targets. One set of results has shown evidence for linguistic guidance.…”

Inefficient conjunction search made efficient by concurrent spoken delivery of target identity

“…On a much broader time scale than that used in Olds et al's (2000aOlds et al's ( , 2000b experiments, Humphreys (1997, 2002) presented one set of colored distractors for a full second before adding to the display a set of different-colored distractors plus the target. They found that participants seemed to remember which distractors had already been discarded as nontargets during that initial second and thus were able to locate the target very efficiently.…”

“…This process can be facilitated by at least two kinds of help-search assistance and visual marking-that seem to work by narrowing down the set of locations at which the target might be found. For example, in the experiments conducted by Olds et al (2000aOlds et al ( , 2000b and Humphreys (1997, 2002), the visual display was incrementally delivered, providing information about locations that no longer needed to be considered and narrowing the search through a restriction in the number of relevant locations.…”

Timing of Speech and Display Affects the Linguistic Mediation of Visual Search

“…According to the biased competition framework, the apparent dichotomy between serial and parallel search processes may not be the result of two separate mechanisms (eg preattentive parallel visual feature extraction followed by a serial attentional spotlight), but rather the product of a single parallel competitive process. This single process is supported by observations of improvement in visual search tasks better described by a graded enhancement of feature salience (Duncan & Humphreys, 1989;Olds, Cowan, & Jolicoeur, 2000a, 2000b, 2000c. Olds et al (2000aOlds et al ( , 2000bOlds et al ( , 2000c presented single-feature visual search pop-out displays for very brief periods of time, less than 100 ms in some conditions, before changing them to conjunction-search displays.…”