Open AccessVisual processing of the impending collision of a looming object: Time to collision revisited
Author(s) -
Yan Jin,
Bailey Lorv,
Hong Li,
Hong-Jin Sun
Publication year - 2011
Publication title -
journal of vision
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.126
H-Index - 113
ISSN - 1534-7362
DOI - 10.1167/11.12.7
Subject(s) - looming , observer (physics) , collision , monocular , object (grammar) , perception , computer vision , computer science , artificial intelligence , variable (mathematics) , visual perception , depth perception , task (project management) , mathematics , psychology , physics , cognitive psychology , computer security , engineering , neuroscience , mathematical analysis , quantum mechanics , systems engineering
As an object approaches an observer's eye, the optical variable tau, defined as the inverse relative expansion rate of the object's image on the retina (D. N. Lee, 1976), approximates the time to collision (TTC). Many studies have provided support that human observers use TTC, but evidence for the exclusive use of TTC generated by tau remains inconclusive. In the present study, observers were presented with a visual display of two sequentially approaching objects and asked to compare their TTCs at the moment these objects vanished. Upon dissociating several variables that may have potentially contributed to TTC perception, we found that observers were most sensitive to TTC information when completing the task and less sensitive to non-time variables, such as those that specified distance to collision, speed, and object size. Moreover, when we manipulated presented variables to provide conflicting TTC information, TTC specified by tau was weighted much more than TTC derived from distance and speed. In conclusion, our results suggested that even in the presence of other monocular sources of information, observers still had a greater tendency to specifically use optical tau when making relative TTC judgments.