Collision Detection in Cluttered Driving Scenes

The purpose of the present experiment was to examine whether drivers’ detection of collisions was altered when the driving scene was cluttered with scene objects. In this experiment stationary scene objects were manipulated by positioning them behind an approaching object and driver motion induced. We found that observers’ collision detection performance (d’) decreased with the presence of scene objects. These results indicate that the ability to detect a collision is altered by the presence of scene objects. In addition, performance was dependent on display duration, with greater sensitivity at increased durations. Moreover, the results showed a significant criterion shift between scene objects present and scene objects absent, with a decrease in identifying a collision object (hit rate) when scene objects were present but no difference in identification of a collision event when scene objects were absent. This suggests that the decreased performance was due to the inability to accurately determine a collision event because of apparent motion of background scene objects due to driver motion. Because the displays used in this experiment are akin to driving in a cluttered environment, the results of this research have important implications regarding driving safety and crash rates particularly in urban environments with complex scenes. Specifically, the results suggest that one factor in cluttered driving scenes is the apparent motion of background scene objects due to driver motion

Training to Improve Collision Detection in Older Adults

Previous studies have indicated a decline in the ability of older adults to detect impending collisions. In addition, previous research has demonstrated that collision detection performance of college-aged participants can be improved with perceptual learning. The present study examined whether perceptual learning can improve performance of older participants on a collision detection task (N=12). The experiment was conducted over seven days with each day consisting of a 1-hr session. Thresholds for three observer speeds were measured prior to training using a two-alternative forced choice procedure during which participants indicated whether an approaching object would result in a collision or noncollision event. Participants were then trained near threshold at one of these speeds for 5 days. After training participants’ thresholds were measured again. Results indicate a significant reduction in the time needed to detect a collision for the trained condition as well as an untrained observer speed condition. Results demonstrate that collision detection performance for older participants can be improved with perceptual learning and may transfer to untrained observer speed