Perception of speed, distance, and TTC of familiar objects

Abstract

It has been shown that knowing the size of an approaching object affects our perception of time to collision (TTC) in a manner similar to the way it affects perception of the physical speed of objects moving in the frontoparallel plane. In this article, we present a series of experiments exploring the effect of object familiarity on the perception of speed and distance in the context of motion in depth (MID), and the interplay among these variables in the perception of TTC. Results of the first experiment show that object familiarity does not help human observers to discriminate the speed of MID. In the second experiment, we show that familiar size may be used to infer the relative distance among objects, in the context of MID, but not to make accurate estimations. Finally, we show that the relative TTCs do not follow the perceived relative distances obtained in the second experiment.