Reversed apparent motion with random dot patterns.

When luminance contrast of target in Braddick-type random dot cinematograms (RDC) is reversed, apparent motion in a direction opposite to the physical displacement is observed. The displacement limit of direction discrimination for this contrast-reversed RDC was found to have three characteristics: (1) the limit resembles that for regular RDC; (2) it is sensitive to target area; and (3) it is limited by the visual angle rather than by number of dots. This indicates that the same short-range process underlies both normal and reversed motion. However, it was found that performance declines remarkably in figural segregation for reversed motion, which suggests that the so called short-range process should be treated as having two distinct components.