Difference of visual perception performance in detection of imminent collision events in stereo and non-stereo viewing conditions

Previous research [1] has shown that, in a nonstereo viewing condition, a circular trajectory collision event (i.e. a collision between a moving object and an observer) is specified by expansion of an object and a constant rate-of-bearing (angular direction or position in the flow field) change. In the present study, we examined the optical information for detecting an imminent collision event in stereo and non-stereo viewing condition, respectively. Under these conditions, the detection performance for a collision event has a significant relation with the viewing condition. Experiment was conducted in which trajectory curvature and viewing condition were varied while time to contact, speed, display duration, and initial image position of the collision objects were maintained. The results indicated that collision detection performance decreased with an increase in trajectory both in stereo and non-stereo viewing condition, and it´s obviously higher in stereo viewing condition than that in non-stereo viewing condition. These results verify that observers can detect collision events on curved trajectories and demonstrate that observers utilize binocular information in collision detection judgment.