Abstract
Previous work on detection of collision objects (Andersen & Kim, 2001) examined objects travelling on linear paths at constant speeds. Under these conditions a collision event is specified by objects that are expanding and that have a constant bearing (the location of the object remains fixed in the flow field). In the present study, we examined the detectability of collisions with objects travelling on circular paths. Collision objects travelling on curved paths do not maintain constant bearing as they approach the observer, but their bearing goes to zero as a collision becomes eminent. The displays simulated observer motion along a straight path, while a spherical object approached along a circular path from the horizon. We varied path curvature and display duration, maintaining time-to-contact, speed, and initial image position of the collision objects. Observers were asked to report whether or not the object was on a path that would result in a collision with the observer. Results show that collision detection accuracy decreases with increasing path curvature. Collision detection accuracy decreases with decreased display duration, especially for highly curved paths. These results indicate that observers can detect collision objects that are on circular paths, with the sensitivity to detect such collisions decreasing as a function of the curvature of the path.
AndersenG.J.KimR.D.(2001). Perceptual information and attentional constraints in visual search of collision events. Journal of Experimental Psychology: Human Perception and Performance, 27, 1039–1056.
Supported by NIH Grant 1R01EY12437