Set size and search type effect on search time during visual search Essay

Set size and search type effect on search time during visual search task - Essay Example Feature Integration theory There are a number of researches with various stimuli, while most prevalent idea proposed for human visual search comes from A. Treisman (1980), who conducted a research illustrating Feature integration theory. It asserts that a visual search is faster in presence of dissimilar background and the number of distracters involved in background do not affect the time consumption in case of a feature search (a search that involves identification of a direct feature like color, shape, orientation or curvature). On the other hand, a conjunction search is affected widely with the number of distracters presented in the background. A conjunction search is defined as a search which does not involve a direct feature but a similarity of multiple features among the various objects. (For example ‘blue square’ has similarities with ‘blue triangle’ and ‘red square’.) Consequent of the propositions, feature integration theory illustrate s that those two searches consists of different methodology for human visual search. Those methods are characterized as parallel searches and serial searches for feature and conjunctive patterns. As further illustrated in Feature Integration theory, feature search and conjunction search differ widely on time consumption patterns as conjunction search follows a twofold process which requires identifying the features and categorizing the conjunctions to create a pattern of search. The distracters found in the patterns are responsible for time consumptions. The feature-integration theory of attention suggests that attention must be directed serially to each stimulus in a display whenever conjunctions of more than one separable feature are needed to characterize or distinguish the possible objects (Treisman and Gelade, 1980) There are number of arguments and theoretical results that involve some serious diversions and modification to this theory. However, most of the theories involve th e base of feature integration which asserts that there are found clear differences in the types of searches when direct features are involved or eliminated. Other theories and Guided search In contrast with feature integration theory there are some proposition which offers different arguments and researches for visual search. A major theory is in the propositions of Wolfe (1989) who offers a broad research for how visual search is not limited only to the factors if the searches are parallel or serial but it also depends largely on the motivating factors for a visual search. Wolfe presents this theory as the guided search theory. In his propositions, a number of subjects were passed through the experiments with varying number of stimuli and the data outcome was measured over the graphs to provide a serious deflection from Feature integration patterns. Subjects searched sets of items for targets defined by conjunctions of color and form, color and orientation, or color and size. Set s ize was varied and reaction times (RT) were measured. For many unpracticed subjects, the slopes of the resulting RT x Set Size functions are too shallow to be consistent with Treisman's feature integration model, which proposes serial, self-terminating search for conjunctions (Jeremy M. Wolfe, 1989). As those results offer a diversion in self-terminating s