The Vertical Visual Field and Implications for the Head-Up Display

Abstract

The present study evaluated dual-task performance as a function of the vertical separation between a tracking task and a discrete-response task, to provide data relevant to the positioning of aircraft head-up display (HUD) information. The data were consistent with Sanders” (1970) research on visual scanning where a nonlinear decrease in performance as a function of the horizontal separation between two displays was observed. Performance is equivalent across a range of visual angles from superimposition to 6.4° vertical separation between displays. The cost to performance is increased for moderate vertical separations (9.6° to 22.5°) where visual scanning is required. At larger separations, the performance cost increases linearly with visual angle, where head movements may begin to supplement eye movements in order to access information. The function which describes the cost of vertical separation was observed to be larger at both small and moderate visual angles when the information in the two displays required integration. The data suggest that nonconformal HUD information may be placed a few degrees down from a superimposed position without a significant performance loss.