Luminance texture increases perceived speed

Abstract

Previous psychophysical experiments have demonstrated that various factors can exert a considerable influence on the apparent velocity of visual stimuli. Here, we investigated the effects of superimposing static luminance texture on the apparent speed of a drifting grating. In Experiment 1, we demonstrate that superimposing static luminance texture on a drifting luminance modulated grating can produce an increase in perceived speed. This supports the hypothesis that texture changes perceived speed by providing landmarks to assess relative motion. In Experiment 2, we showed that contrary to static luminance texture, dynamic luminance texture did not increase perceived speed. This demonstrates that texture must provide reliable spatial landmarks in order to generate an increase in perceived speed. The results of Experiment 3 demonstrate that perceived speed depends on the size of the area covered by texture. This suggests that luminance texture and the motion stimulus interacted with each other over a limited spatial scale and that these local responses are then pooled to determine the speed of the motion stimulus. In Experiment 4, we showed that static texture contrast could produce a greater effect than motion stimulus contrast on perceived speed and that these effects could still be observed at brief presentation times. We discuss these findings in the context of models proposed to account for phenomena in the perception of speed.

The effect of contrast on pedestrians’ perception of vehicle speed in different road environments

“…We suppose that the increase of the perceived speed in the enriched road environments resulted from the addition of relative motion cues as vehicle motion was then viewed against the reference points. This interpretation would be in line with previous studies showing a similar increase of perceived speed with the addition of a static visual surrounding (e.g., Blakemore and Snowden, 2000, Brown, 1931, Gogel & McNulty, 1983, Nguyen-Tri & Faubert, 2007. In terms of the interpretation of the speed bias observed in fog, the fact that perceived speed increased in both simple and more enriched road environments suggests that a bias in the perceived vehicle distance may not be the primary driver.…”

Equivalence of physical and perceived speed in binocular rivalry

“…In general, the perceived speed of a central region is greatly increased when its surround moves in the opposite direction (Norman, Norman, Todd, & Lindsey, 1996) but is reduced by a surround moving in the same direction (Loomis & Nakayama, 1973;Walker & Powell, 1974). To some extent, this is dependent on the relative velocity of the surround (Loomis & Nakayama, 1973;Norman et al, 1996), but similar effects have been reported recently with static surrounds (Blakemore & Snowden, 2000;Nguyen-Tri & Faubert, 2007). Related effects of facilitation and inhibition also occur when the stimuli are arranged in adjacent rows (Bressan, 1991;Nawrot & Sekuler, 1990).…”

Comparing the effect of the interaction between fine and coarse scales and surround suppression on motion discrimination

“…We have shown that a simple model of motion sensing that implements a subtractive interaction between motion sensors tuned to high and low spatial frequencies can account for the facilitation effect; however, there are other results that could explain our facilitation effect. For example, it has been found that static luminance texture increases perceived speed (Nguyen-Tri & Faubert, 2007). These authors found that when a static grating of 2 c/deg was added to a moving grating of 0.5 c/deg, the perceived speed of the low-frequency pattern increased 1.25 times.…”