Representational momentum is a small, but reliable, error in our visual perception of moving objects. Representational moment was discovered and named by Jennifer Freyd and Ronald Finke. Instead of knowing the exact location of a moving object, viewers actually think it is a bit further along its trajectory as time goes forward. For example, people viewing an object moving from left to right that suddenly disappears will report they saw it a bit further to the right than where it actually vanished. While not a big error, it has been found in a variety of different events ranging from simple rotations to camera movement through a scene. The name "representational momentum" initially reflected the idea that the forward displacement was the result of the perceptual system having internalized, or evolved to include, basic principles of Newtonian physics, but it has come to mean forward displacements that continue a presented pattern along a variety of dimensions, not just position or orientation. As with many areas of cognitive psychology, theories can focus on bottom-up or top-down aspects of the task. Bottom-up theories of representational momentum highlight the role of eye movements and stimulus presentation, while top-down theories highlight the role of the observer's experience and expectations regarding the presented event. Methods Representational Momentum has been studied using two types of displays: implied motion (left panel) and smooth animations (right panel). Implied events show a series of pictures that suggest a motion, but at a slow frame rate so there is no apparent motion. Smooth animations have also been used, where the animation is briefly interrupted and then participants either indicate whether a static probe is in the same position as the final frame of the animation (right panel), or are asked to indicate with a mouse cursor exactly where the object disappeared. The basic result is that participants either use the mouse to click beyond the vanishing point, or misidentify forward positioned probes as the location where the object disappeared. So, instead of indicating that the actual 0° probe in a rotation event is the same, participants will say that probes appearing 2°-4° past the vanishing point actually seem to be at the vanishing point itself. However, they will quite readily reject probes that are behind the vanishing point by 2°-4°. Specific results Initial studies established that representational momentum occurs for rotations in and movements across the picture plane, with larger distortions