Distribution of visual attention in head-worn displays

With head-worn displays, information can be presented in addition to the real surround. But, the virtual information is selfilluminating, has an unclear depth, and, depending on the visual background, the signal-noise ratio and the brightness contrast varies. We examined performance in a visual search task in which a 0 had to be found under O. The head-worn display was placed in front of the monitor so that the stimuli overed the same parts of the visual field. Performance on the head-worn display was worse than on the monitor. Searching a mixed display (half of the stimuli occurred on the monitor, half on the head-worn display) took more time than expected by unitary performances. These costs must be attributed to switching between both media. The results suggest that the distribution of attention in depth is restricted.