Ricky K.C Au

Ricky Au

Ricky Au obtained his bachelor degree in psychology and M.Phil. degree in neuropsychology at the University of Hong Kong in 2006 and 2009 respectively. Currently, he is in the Ph.D. course in Cognitive Science at the University of Tokyo in Japan, working with Katsumi Watanabe. His main interest of research is in visual perception and psychophysics.

APVC 2013 - Mislocalization of a moving object in three-dimensional space.

Ricky K. C. Au, Katsumi Watanabe, The University of Tokyo

Our visual system exhibits systematic biases in localizing visual objects. This is particularly evident when it localizes the position of a moving object. The present study explored the position perception of a visual object moving in depth at a relatively fast velocity for a long distance. Observers viewed an object moving in a constant velocity of 2 m/s per second for 1000 ms, which was either directly approaching toward or receding from them, on a 3D projector. The entire background was flashed at various timings during the movie. After the movie, a probe object was presented at various distance from the observer.

The observers judged whether the probe was closer to (or farther away from) them, compared with the perceived position of the moving object at the time of the flash. The results showed that the observers tended to report that the position of the approaching object was farther away and that of the receding object was closer to them, compared with the probe object (i.e., underestimation). However, when the flash occurred early in the approaching condition and therefore the position to be reported was far away from the observer, the position of the approaching object was reported closer to the observer (i.e., overestimation). Such reversal of mislocalization was not observed in the receding condition. Subsequent experiments revealed that it was the distance from the observer rather than the flash timing relative to the motion onset that determined whether underestimation or overestimation would occur.

These results suggest that the visual system might estimate the distance of objects differently for objects approaching toward and those receding from the observer.

Click on thumbnail to view a PDF of the winning poster.


APVC 2013 - PosterMislocalization of a moving object in three-dimensional space.