Age-related differences in collision detection during deceleration

Observers were presented with displays simulating a 3-D environment with obstacles in the path of motion. During the trial, observer motion decelerated at a constant rate and was followed by a blackout prior to the end of the display. On some trials the rate of deceleration resulted in stopping before the collision, whereas on other trials the rate of deceleration resulted in a collision with the obstacles. The observer's task was to detect which trials simulated an impending collision. Proportion of collision judgments was greater for older as compared with younger observers when a collision was not simulated. Older observers showed less sensitivity to detect collisions than younger observers did, particularly at high speeds. The age-dependent results are discussed in terms of analyses based on tau and constant deceleration. The results suggest that increased accident rates for older drivers may be due to an inability to detect collisions at high speeds.