Abstract
PURPOSE: Solid objects do not move through other solid objects. Previous work indicates that this real-world constraint may influence perceived motion trajectory (e.g., Shiffrar & Freyd, 1990); we sought to determine whether it influences motion correspondence. METHOD: The experiment utilized bistable quartets, in which motion (and motion correspondence) is typically perceived along either of two competing paths. Over several blocks of trials, O's viewed apparent motion displays of three real-world versions of a bistable quartet consisting of balls on a carpeted floor (a) alone, (b) with a solid barrier across one of the possible paths of motion, or (c) with a flat stripe on the carpet, the stripe having the same approximate size, shape, color, and location as the barrier in condition (b). RESULTS AND CONCLUSIONS: The presence of either the barrier or the stripe produced a general bias for motion parallel to the barrier or stripe. While the results of the barrier and stripe conditions differed from the balls-alone condition, they did not differ from each other, suggesting that the bias for motion parallel to the barrier does not reflect a general solidity constraint.