Item

Abstract

Velocity perception has been investigated in many experiments with stimuli moving in the picture plane (2-D). For example, experiments with sine-wave gratings have shown that high-frequency patterns are perceived as moving faster than low-frequency patterns, and that high-contrast patterns are perceived as moving faster than low-contrast patterns. We investigated the influence of contrast and spatial frequency on perceived velocity in an open-loop driving simulation to determine whether contrast and spatial frequency account for differences in perceived velocity in complex 3-D environments. The simulated scene consisted of a textured road flanked by two meadows. We used road surface textures with different contrast and spatial frequency contents. In a 2AFC paradigm participants were simultaneously presented two driving simulation sequences depicting vehicles moving at different velocities on roads with different surface textures. Participants judged which vehicle was moving faster. Using an adaptive staircase procedure we determined the point of subjective equality for roads with different surface textures. The results show that perceived velocity in a driving simulation does depend on contrast and spatial frequency of the surface texture. Perceived velocity can be increased by increasing the contrast or the relative amount of high spatial frequencies in the surface texture. The relevance of these results for the design of driving simulators is discussed.