Evidence from Motion

Perceived motion is defined as the apparent speed and direction of objects that are translating and/or rotating in three-dimensional space. It has long been clear, however, that the perceived speeds and directions of moving objects disagree with physical measurements of motion. With respect to speed, the flash-lag effect has been a major focus; with respect to direction, the emphasis has been on the effects of apertures. These phenomena—and many others—raise the question of how we routinely succeed in the world despite blatant discrepancies between the motions we see and the physical speeds and directions of the objects we must deal with. Resolving this puzzle presents another body of evidence pertinent to whether empirical ranking is the way nervous systems link objective and subjective domains.