The onset repulsion effect

There have been many previous reports of mislocalization associated with moving objects (e.g. flash-lag effect, Frohlich effect, representational momentum). Across four experiments, a new form of mislocalization--the onset repulsion effect (ORE)--is explored in which the error is always back along the observed path of motion. That is, when observers are asked to localize both the initial onset and the final offset positions of a moving object, by far the largest and most systematic error they make is in placing the onset point too early along the correct path of motion. Errors orthogonal to the path of motion and errors in localizing the offset point are minimal by comparison. Errors are also very small when motion is implied rather than continuous. The ORE can be observed with and without fixation, and as with other mislocalization effects, shows some dependence on direction and velocity. As the most obvious prediction in these studies, based on previous reports of mislocalization and the known properties of the visual system, would be for forward rather than backward errors, discussion will focus on the type of mechanism that may have given rise to the observed pattern of results.