Resource Allocation and Object Displays

Abstract

Object displays are receiving increasing interest due to their potential contribution to display designs and to the understanding of basic visual attention mechanisms. The aim of the present research is to develop a more in depth understanding of the attention mechanisms involved in object perception. Multidimensional information was presented in the form of an object that was defined by its color, form, and size. Subjects' ability to divide and focus attention on a specific dimension of the object were examined as a function of (a) the number of irrelevant varying dimensions, (b) the uncertainty of the relevant dimension, and (c) the number of objects that the subjects simultaneously attend to. Two possible mechanisms by which processing resources can be allocated among the dimensions of an object were explored. Three task conditions with various degrees of irrelevant information were presented in a single or dual object display. The task was to identify one of the dimensions as quickly and as accurately as possible. As predicted by Kahneman and Treisman's object file model, results show that all dimensions of the object appeared to be processed. This was evidenced by the influence of the irrelevant size variation on color and form identification. However, the data suggest that although all dimensions were processed they were not processed without cost. Attention appeared to be divided among the dimensions. As the number of dimensions increased, the amount of attention available for each of the dimensions would be reduced. Further, only a small difference between the single and dual object case was detected. The small difference attests to a relative ease in selective attention between relevant and irrelevant objects.