Boundary Extension and Perceived Motion

Boundary extension is a memory error in which a person remembers seeing beyond the boundaries of a view (Intraub & Richardson, 1989). Representational momentum is another type of memory error, in which a person remembers the last seen position of a moving object being further along its trajectory path than it actually was (Hubbard, 1995). The goal of this experiment was to assess the influence of implied motion on boundary extension. On each trial within the three experiments, participants saw a picture of a scene with an object that moved either forward or backward, in either a coherent manner or not. Memory for the views was measured with a border-adjustment task. Results revealed a significant effect of motion direction. When motion direction was forward, participants moved the approaching border significantly inward, toward the object. When motion direction was backward, participants moved the approaching border significantly outward. This implies that participants’ knowledge about the type of motion depicted in a scene influences memory.