Where is the moving object now? Judgments of instantaneous position show poor temporal precision (SD = 70 ms).

Humans can precisely judge relative location between two objects moving with the same speed and direction, as numerous studies have shown. However, the precision for localizing a single moving object relative to stationary references remains a neglected topic. Here, subjects reported the perceived location of a moving object at the time of a cue. The variability of the reported positions increased steeply with the speed of the object, such that the distribution of responses corresponds to the distance that the object traveled in 70 ms. This surprisingly large temporal imprecision depends little on the characteristics of the trajectory of the moving object or of the cue that indicates when to judge the position. We propose that the imprecision reflects a difficulty in identifying which position of the moving object occurs at the same time as the cue. This high-level process may involve the same low temporal resolution binding mechanism that, in other situations, pairs simultaneous features such as color and motion.