Abstract A region in an alternated pair of random-dot patterns was uniformly displaced. It was perceived as a segregated, coherently moving shape only if the displacement was small. The limit on the displacement was its absolute size (maximum about 15ȃ) rather than the number of elements' widths. Segregation due to apparent motion did not occur if the two patterns were exposed to different eyes. These conditions for segregation differ from those classically found for apparent motion. Perceptual segregation may be due to the activity of low-level motion detectors of limited spatial range, while classical apparent motion with larger displacements involves a different process. The problem of selection among alternative possible interactions of stimulus elements in apparent motion is discussed.