Effects of Noise and Workload on Performance with Two Object Displays vs. a Separated Display

Abstract

This study examines the effects of stress on the processing of displayed information from two types of object displays, when dimensions were formed by the color and size of a bar, by the height and width of a rectangle, and from a separated two bargraph display. Subjects either integrated information across the two dimensions of each display or focused attention on each dimension, in a simulated airborne decision task. In Experiment 1 (14 subjects), stress was imposed via three levels of workload of a concurrent visual search task. In Experiment 2 (14 subjects), it was imposed by 88 dB helicopter noise. Results indicated that information integration was best supported by the rectangle display at higher levels of workload. Both the color bar and the bargraph display were associated with poor performance on the integration task, but were superior on the focused attention task. Hence, an emergent feature of the rectangle (its area), rather than objectness per se, was the critical element supporting information integration and disrupting focused attention. The imposition of noise enhanced the subjective feeling of stress. Noise did not influence performance on the decision task, but differentially affected the resources necessary to extract that information. Noise reduced the resource demands of both object displays and increased the resource demands of the separate bargraph display.