Abstract:

Representational momentum (RM) is the term used to refer to a systematic misrepresentation in memory of an object’s position in space. In contrast to using simple patterns as the stimuli, the use of naturalistic objects as stimuli enabled researchers to learn more about typical-motion effects. Nagai and Yagi (2002) thought that the finding of typical-motion effects might imply that a pointed-shaped object moving in the direction of its point produced larger forward displacement than did a pointed-shaped object moving in the opposite direction, because the objects used in these studies had a clear sharp point at their fronts. However, was pointedness the only cause of typical-motion effects? We hypothesized that another possible cause of typical-motion effects was the facing orientation effect, by which we mean, the direction that the face is facing. It was necessary to separate these two factors in exploring the causes of typical-motion effects. One possible way to do this is to use symmetrically shaped naturalistic objects to exclude the influence of pointedness. The present research aimed to explore whether facing orientation influences representational momentum through four experiments. We used a 2(facing orientation: forward vs. backword) ×2(direction of motion: leftward vs. rightward/ upward vs. downward) within-subjects design and used implied motion paradigms in all four experiments. The dependent variable was a weighted measure. In experiment 1, we used symmetrical figures, which included eyes to manifest facing. We chose the hedgehog figure because in the real world a hedgehog only moves forward. In experiment 2, we changed the design of experiment 1 by using a more abstract figure that was symmetrical and only included eyes manifest facing. In experiment 3, we used Pacman as a stimuli. Pacman was a game software made by Namco, a game software company. Pacman was a little yellow guy with a big head and a really large smile who run away from the ghosts trying to eat all the pellets. The mouth in Pacman manifests facing, and the shape of the mouth is a sharp angle. Because the contour of Pacman contains a sharp angle and facing orientation at the same time and their orientation are in contradiction, we can compare the size of the pointedness and the facing effect. In experiment 4, we used Pacman as stimuli. The motion direction was vertical. We wanted to explore whether the results of the first 3 experiments were influenced by reading habits because the weighted mean for moving forward motion was larger than moving backward in the level of moving right in experiments1, 2, and 3. The results of experiment 1 and 2 indicated that facing orientation effect was the most likely causes of typical-motion effects. Experiment 3 found that facing orientation effect was stronger than pointedness effect when both effects occurred simultaneously, and had opposing effects. Experiment 4 found that facing orientation effect also occurred when stimuli moved vertically. In summary, facing orientation effect was a possible cause of typical-motion effects. Because facing orientation effect only occurred when the stimulus was moving right and down, lateral reading habits and gravity were suggested to be the underlying reason of facing orientation effect. The representational momentum is cognitively penetrable.

Key words: representational momentum, displacement, pointedness effect, facing orientation