The Role of Visual Attention in Head-Up Displays: Design Implications for Varying Symbology Intensity
Twenty pilots from the University of Illinois flew a low fidelity simulator during cruise flight. The intensity of the display symbology was manipulated in three different weather conditions to influence the discriminability of the instrumentation. The symbology was displayed in either head-up or head-down locations, with equivalent optical distances and display formats. Half of the subjects flew with a conformal symbology set, while the other half flew with a partially conformal symbology set. Responses to near and far domain events were measured, and tracking error of the three axes of control was calculated. The results revealed a head-up advantage to the far domain event detection and a head-down advantage to the near domain event detection. Performance in the head-up condition approached that of the otherwise superior head-down condition when an appreciable contrast between the symbology and the background environment was provided. The results are discussed in terms of an effect of the modulation of focused attention.