The temporal course of the relationship between retinal disparity and the equidistance tendency in the determination of perceived depth

Changes in perceived depth as a function of exposure duration were compared for two stimulus conditions. In one. a depth interval between two points of light was produced by the retinal disparity cue, and in the other condition, otherwise identical to the first, the light points were connected by a thin luminous line. The principle finding was that the perceived depth interval between the light points increased as a function of exposure durations greater than 1 sec, while no change in the perceived depth interval between the end points of the line occurred. The results were interpreted in terms of a greater equidistance tendency (ET) operating for the line than for the point condition. It was concluded that both the ET and the retinal disparity cue increase in strength as a function of exposure duration.