Eye Movements in Search and Target Acquisition

Abstract

The frequency distribution of eye fixations and fixation durations during a search and target acquisition task was examined to determine if the allocation of visual attention was related to target, scene, and/or observer characteristics. Ninety computer-generated scenes simulating infrared imagery and containing different levels of clutter and zero, one, two, or three targets were produced. Targets were embedded in these scenes counterbalancing for range and position. Global and local clutter were measured using both statistical variance and probability of edge metrics. Thirty-three aviators, tankers, and infantry soldiers were shown still video images of the 90 scenes and were instructed to search for targets. Results of multiple regression analyses of global clutter, local clutter, range, number of targets, target dimensions, target complexity, and group membershi on eye fixations and fixation durations are given and discussed in terms of search strategies.