The Span of Visual Processing in Tactical Displays

Abstract

Visual span, or the region of the visual field from which information is extracted during a fixation, may vary as a function display complexity. As display technology evolves, military tactical displays show increasing quantities of information, often across large areas. To quantify the breadth with which an operator may process information presented in a tactical display, we related search performance to the amount of the display processed without an eye movement. The derived visual span measure was used to test the possibility that task requirements have an impact on the spatial extent of ”at a glance” processing. We compared visual span on searches based on threat affiliation (color) to those based on a combination of threat affiliation and heading (color and orientation) for two naval tactical symbol sets. We found that the task an operator engaged in while searching a complex tactical display affected the portion of the display that was processed ”at a glance”.