Dynamic representation of physical states
When a log burns, it transforms from a block of wood into a pile of ash. Such state-changes are among the most dramatic ways objects change, going beyond mere changes of position or orientation. How does the mind represent changes of state? A foundational result in visual cognition is that memory extrapolates the positions of moving objects—a distortion called "representational momentum." Here, four experiments (N=300 adults) exploited this phenomenon to investigate mental representations in "state-space." Participants who viewed objects undergoing state- changes—e.g., ice melting, logs burning, or grapes shriveling—remembered them as more changed (e.g., more melted, burned, or shriveled) than they actually were. This pattern extended to several types of state-changes, went beyond their low-level properties, and even adhered to their plausible trajectories in state-space. Thus, mental representations of a dynamic world actively incorporate change, in surprisingly broad ways: Whether in position or state, memory extrapolates how objects change.