Space and Time in Perception and Action: Conceptual influence on the flash lag effect and representational momentum
When judging the position of a moving object, human observers do not perceive and memorize the moving object's correct position. There are two known phenomena in judged position errors of a moving object, representational momentum (RM) and the flash lag effect (FLE) both of which we consider here. RM was originally reported by Freyd and Finke (1984) Freyd and colleagues displayed a series of still frames to imply the rotation of a rectangle (e.g. Freyd Finke 1984, 1985; Freyd Johnson 1987) Observers saw three views of a rectangle at different rotations about its center, with 250 ms display duration with 250 ms interstimulus interval. The fourth rectangle was presented as a probe 250 ms after the third frame presentation. The rotation of the probe was selected from possible positions symmetrically distributed around the actual third position of rectangle. Observers were asked whether the rectangle in the third frame (the last frame of the motion sequence) was the same orientation as the probe. The results showed that their memory for the third orientation tended to be shifted in the direction of rotation. In other words, the orientation of the probe rectangle had to be rotated slightly further to be judged as being in the same position as the third rectangle. To account for the forward shift of the final position of a stimulus undergoing implied motion, some authors postulate that the dynamics of the representational system follow physical laws, such as momentum (representational momentum; RM Finke Freyd 1985; Finke et al. 1986; Freyd 1987; Finke Shyi 1988) RM is a robust effect as observed with smooth object motion and in pointing at the final position of a moving object (e.g. Hubbard Bharucha 1988) Several variables influence RM (for review, Hubbard 1995b) RM increases with the velocity (e.g. Freyd Finke 1985; Hubbard Bharucha 1988; Nagai Saiki 2005) and acceleration of the moving target (Finke et al. 1986) pointing to the similarity between RM and physical momentum. Hubbard and others demonstrated that RM may reflect physical principles. For example, RM increases downward, in the direction of gravity (Hubbard Bharucha 1988; 1995a, 1997; Reed Vinson 1996; Hubbard Ruppel 1999; Nagai et al. 2002; Vinson Reed 2002) whereas implied friction between a moving stimulus and an adjoining surface reduces RM (Hubbard 1995a; see also Nagai Yagi 2001) Moreover, RM is influenced by real world knowledge of the typical motions of familiar objects (Freyd