Abstract
Two experiments were executed in order to investigate the relationship between attention in real three-dimensional (3-D) space and depth perception. Three fixation points were located on the central line of sight. They were located 140 cm, 240 cm, and 340 cm from the observer. Two near targets and two far targets were arranged around each fixation point. Spatial cuing paradigm (Posner et al.,1978) was used in order to control observers' expectancy. Following detection of a target, depth estimation between a fixation point and a target (magnitude estimation) was required. In experiment 1, the distance of fixation points from observers were changed randomly every trial. On the other hand, they were blocked in experiment 2. Other conditions were the same in both experiments. The result of experiment 1 showed that the estimation of depth was more adequate when the expectancy was valid in nearer fixation point than when the expectancy was invalid. That is, it is suggested that depth perception depends on whether observers expected the position of targets or not and on the validity of expectancy. In experiment2, more remarkable result was shown in all fixation points.
The reaction time of target detection around far fixation point was longer than around near fixation in experiment2. This seems to indicate the viewer-centered representation. In addition, the results on reaction time and depth perception in experiment1 have the interference that observers should allocate attention over all fixation points every trial. However, in experiment2, because they could allocate attention around only one fixation point as object-centered representation, the performance were better than experiment1. It is suggested that the representation of attention in 3-D space may be constructed by interaction between viewer-centered and object-centered representations.