Transformational Apparent Motion


In simple apparent motion displays, the shape of the moving object remains constant from frame to frame in the animation sequence. In 'transformational apparent motion' displays, the shape of the object changes during its motion, and this shape change presents the visual system with a problem - how does it match up the differing shapes from frame to frame? Perceived movement reflects the solution adopted. The animation on the right contains only two frames, one with an incomplete horizontal bar across the 'H', and one with a complete bar. Yet the bar appears to grow and shrink smoothly. This effect was first described by the Belgian psychologist Albert Michotte in 1950:
"One projects onto a screen any colored shape, such as a circle, and suddenly changes its color, size, or shape . . . Under these conditions, one can have the impression that the object has undergone a change while remaining 'itself'. The same colored circle has become greenish, for example, or has dilated, or become oval... In fact, the change is so rapid that it always appears to be a partial evolution of the object, and it then occurs as a 'growing into', and by virtue of this has its own anterior temporal limits."
Tse et al. (1998) found, as did Michotte, that the apparent motion seen during such transformations is influenced by contour continuity, color, texture, and shape. The importance of form indicates that a high-level matching or “parsing” process is involved in the generation of apparent motion.
Tse, P., Cavanagh, P., & Nakayama, K. (1998). The role of parsing in high-level motion processing. In T. Watanabe (Ed.), High-level Motion Processing (pp. 249–266). Cambridge, MA: MIT Press.
Thines, G., Costall, A., & Butterworth, G. (Eds.) (1991). Michotte’s Experimental Phenomenology of Perception. Hillsdale, NJ: Lawrence Erlbaum Associates, Inc.
Zhou, Y., Zhou, T. G., Rao, H. Y., Wang, J. J., Meng, M., Chen, M., et al. (2003). Contributions of the visual ventral pathway to long-range apparent motion. Science, 299, 417–420.