Object-motion detection affected by concurrent self-motion perception: applied aspects for vehicle guidance.

Thresholds and response times for object-motion detection are significantly raised during concurrent real or visually induced self-motion perception. This was demonstrated by standardized laboratory experiments in which subjects had to react to a suprathreshold visual stimulus (1 degree-light spot moving with 5 degrees/s speed) under different stimulus conditions of simultaneously perceived self-motion. Elevated response times (mean elevation factor: 3.27) were also obtained for the detection of changes in inter-vehicle distance (headway) under real road conditions with the simultaneous involvement of self- and object-motion perception compared to a corresponding (object-motion perception) simulation in the laboratory without any self-motion. With regard to vehicle guidance, existing concepts of safe stopping distances, which depend upon adequate detection of a collision course and the corresponding reaction times, have to be recalculated.