Speed-tuned mechanism and speed perception in human vision

Abstract

SUMMARYIn this study, the spatiotemporal characteristics of human speed perception are measured in the spatiotemporal frequency domain through a psychophysical experiment. Based on the experimental results, the mechanism for speed perception is investigated. The existence of a speed-tuned mechanism and the role of the temporal frequency in speed perception are demonstrated. The method of speed comparison by simultaneous presentation is used in the experiment. Two moving gratings are used as the standard and the comparison stimuli, and the "stimulation of subjectively equal speed" (SSES) is determined for the standard stimulus in spatiotemporal frequency coordinates. As experimental results, two different spatiotemporal characteristics are shown. For the speed range lower than 3.2 deg/s, the speed perception depends only on the physical speed of the stimulus, which suggests the existence of a speed-tuned mechanism. In the range higher than that value, the speed perception depends on the physical speed and the temporal frequency of the stimulus, indicating that both a speedtuned mechanism and a temporal frequency-tuned mechanism are involved. Based on these experimental results, the human mechanism in speed perception is described by using a speed-tuned mechanism and a temporal frequencytuned mechanism. A basic framework for a speed perception model is proposed.

Effects of edge rate of the designed line markings on the following time headway

“…In this study, when the edge rate falls in [5 Hz,14 Hz], the speed decreases along with the increase in edge rate; in the study of Liu et al [22], a similar speed reduction occurred as the edge rate increased from 8 Hz to 16 Hz. Though we conducted experiments in a real-world expressway, which was signi cantly di erent from the simulation study of Liu, the similar result could be taken from the quantitative relation between perceived and physical variables that were introduced by Shen et al [18]. Shen et al [18] introduced the equation V p = V n : f 1 n t = V:f 1 n s (because V = f t =f s ), where V p is the perceived speed; V is the actual speed; f t is the temporal frequency; f s is the spatial frequency; and n is the undetermined constants.…”

“…Though we conducted experiments in a real-world expressway, which was signi cantly di erent from the simulation study of Liu, the similar result could be taken from the quantitative relation between perceived and physical variables that were introduced by Shen et al [18]. Shen et al [18] introduced the equation V p = V n : f 1 n t = V:f 1 n s (because V = f t =f s ), where V p is the perceived speed; V is the actual speed; f t is the temporal frequency; f s is the spatial frequency; and n is the undetermined constants. When the speed or the temporal frequency is high enough, parameter n falls in [0,1], i.e.…”

“…According to Shen et al [17,18], edge rate can also be derived from the temporal frequency (f t ) and the spatial frequency (f s ). Signals can be measured by temporal frequency (f t ) when they vary periodically in time, which normally can be measured by a unit of Hz.…”

Facilities Design Based on Apparent Motion of Grating for Speed Reduction in Tunnel

“…The experiment adopted Stimulation of Subjectively Equal Speed [11] (SSES) as the performance index to measure the speed that the subject perceives. SSES is the physical speed of "comparison stimuli" when the perceived speed of "comparison stimuli" is equal to the one of "standard stimuli".…”

Assessing lag perception in electronic sketching

“…To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. NordiCHI '12, October [14][15][16][17]2012 Copenhagen, Denmark Copyright 2012 ACM 978-1-4503-1482-4/12/10... 15.00" battery. Besides that, the increasing availability of low-end smartphones [10] makes performance a critical issue for applications designed to run on mobile devices.…”