The effect of stereoscopic viewing in a word-search task with a layered background

— The benefits of stereoscopic viewing were explored in searching in words superimposed over a background. In the first experiment, eight participants searched for text in a normal 2-D display, a 3-D display using a parallax barrier, and a darkened 2-D display of equivalent brightness to the 3-D display. Word-search performance was significantly faster for the bright 2-D display vs. the 3-D display, but when brightness was controlled, performance on the 3-D display was better relative to the 2-D (dim) display. In a second experiment, the effect of floating text vs. sinking background disparity was assessed across four background conditions. Twenty participants saw only the floating-text (FT) condition and 20 participants saw only the sinking-background (SB) condition. Performance of the SB group was significantly better than that of FT group, and the advantage of SB disparity was greater with the more-complex backgrounds. Thus, when a parallax-barrier 3-D display is used to view text or other figural information overlaid on a background, it is proposed that the layer of primary interest (foreground) should be displayed with zero disparity (on the physical display surface) with the secondary layer (background) appearing to be sunk beneath that surface.