Simulation of Driving in Low-Visibility Conditions: Does Stereopsis Improve Speed Perception?

Brooks, Kevin R.; Rafat, Mohammed E

doi:10.1068/p7779

Cited by 18 publications

(26 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our JND estimates are generally consistent with figures obtained under quite different laboratory conditions, stimuli and paradigms in humans 10 , 11 and in monkeys 12 , as well as with more or less realistic optic flow stimuli in car driving contexts 13 – 16 . However, we also directly compared the results obtained in a classical laboratory setting (second experiment) with those obtained in a condition that mimicked home TV watching (first experiment), showing in the latter case an even poorer sensitivity to altered video speed.…”

Section: Discussionsupporting

confidence: 87%

Low perceptual sensitivity to altered video speed in viewing a soccer match

de'Sperati

Baud-Bovy

2017

Sci Rep

View full text Add to dashboard Cite

When watching videos, our sense of reality is continuously challenged. How much can a fundamental dimension of experience such as visual flow be modified before breaking the perception of real time? Here we found a remarkable indifference to speed manipulations applied to a popular video content, a soccer match. In a condition that mimicked real-life TV watching, none of 100 naïve observers spontaneously noticed speed alterations up/down to 12%, even when asked to report motion anomalies, and showed very low sensitivity to video speed changes (Just Noticeable Difference, JND = 18%). When tested with a constant-stimuli speed discrimination task, JND was still high, though much reduced (9%). The presence of the original voice-over with compensation for pitch did not affect perceptual performance. Thus, our results document a rather broad tolerance to speed manipulations in video viewing, even under attentive scrutiny. This finding may have important implications. For example, it can validate video compression strategies based on sub-threshold temporal squeezing. This way, a soccer match can last only 80 min and still be perceived as natural. More generally, knowing the boundaries of natural speed perception may help to optimize the flow of artificial visual stimuli which increasingly surround us.We are almost literally immersed in an artificial visual world, made in large part by motion pictures. How robust is our sense of reality with such pervasive technologies? For example, how well can we detect speed alterations in a video clip? The availability of videos, videogames and virtual reality systems, through which a variety of arbitrarily altered worlds can be experienced, calls for an appraisal of the boundaries within which video speed can be manipulated without conflicting with perception. However, although much effort has been devoted to studying motion perception 1,2 , how we perceive the speed of real-life scenes is still largely unknown, due especially to stimulus complexity and the presence of cognitive, higher-order factors 3-5 . Here we have addressed natural speed perception by measuring the detectability of speed alterations applied to a soccer match video clip. ResultsRetrospective noticing. In the first experiment we used a rather ecological setting, with observers watching a 10-minute video clip of a soccer match without any specific task. They viewed it only once and were told that at the end they would have to answer questions concerning the match, aimed to assess attention and memory capabilities. Observers were divided into five groups (N = 25 each), and each group watched the video clip at a different speed (0.88x, 0.96x, 1.00x, 1.04x and 1.12x, where 1.00x is the original video speed -30 fps; see Methods). The original audio track with voice commentary was pitch-compensated to avoid distortions when the video was played at a different speed. In general, observers were quite compliant, as suggested by self-reported attention measures (mental concentration: 60%, event-following: 81%). By contras...

show abstract

Section: Discussionsupporting

confidence: 87%

Low perceptual sensitivity to altered video speed in viewing a soccer match

de'Sperati

Baud-Bovy

2017

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Driving simulation studies showed that participants in computer-generated driving simulations not only perceived foggy (vs. clear) scenes to move more slowly [ 19 ] but also “drove” faster than a given target speed in simulated fog [ 20 ]. This finding was replicated using filmed footage of actual traffic situations [ 21 , 22 ]. However, these studies have been criticized for representing a poor model of motion perception in three-dimensional environments, because contrast was reduced uniformly and independently of distance.…”

Section: Introductionmentioning

confidence: 73%

Blind haste: As light decreases, speeding increases

Bellis

Schulte‐Mecklenbeck

Brucks³

et al. 2018

PLoS ONE

View full text Add to dashboard Cite

Worldwide, more than one million people die on the roads each year. A third of these fatal accidents are attributed to speeding, with properties of the individual driver and the environment regarded as key contributing factors. We examine real-world speeding behavior and its interaction with illuminance, an environmental property defined as the luminous flux incident on a surface. Drawing on an analysis of 1.2 million vehicle movements, we show that reduced illuminance levels are associated with increased speeding. This relationship persists when we control for factors known to influence speeding (e.g., fluctuations in traffic volume) and consider proxies of illuminance (e.g., sight distance). Our findings add to a long-standing debate about how the quality of visual conditions affects drivers’ speed perception and driving speed. Policy makers can intervene by educating drivers about the inverse illuminance‒speeding relationship and by testing how improved vehicle headlights and smart road lighting can attenuate speeding.

show abstract

“…His findings suggest that the sense of vection is strengthened by stereoscopic informationnot by way of disambiguating optic flow and environmental depth, but rather by feeding an additional channel for motion in depth, which independently supports the sense of vection. Similarly, perceived egomotion speed from video clips of car driving is higher if the clips are stereoscopically presented (Brooks & Rafat, 2015). Gray and Regan (1998) investigated the role of stereoscopic disparities and image expansion in the perception of time to collision and found that accuracy and discrimination are best if both cues are available.…”

Section: Introductionmentioning

confidence: 99%

The perception of ego-motion change in environments with varying depth: Interaction of stereo and optic flow

et al. 2016

View full text Add to dashboard Cite

When estimating ego-motion in environments (e.g., tunnels, streets) with varying depth, human subjects confuse ego-acceleration with environment narrowing and ego-deceleration with environment widening. Festl, Recktenwald, Yuan, and Mallot (2012) demonstrated that in nonstereoscopic viewing conditions, this happens despite the fact that retinal measurements of acceleration rate-a variable related to tau-dot-should allow veridical perception. Here we address the question of whether additional depth cues (specifically binocular stereo, object occlusion, or constant average object size) help break the confusion between narrowing and acceleration. Using a forced-choice paradigm, the confusion is shown to persist even if unambiguous stereo information is provided. The confusion can also be demonstrated in an adjustment task in which subjects were asked to keep a constant speed in a tunnel with varying diameter: Subjects increased speed in widening sections and decreased speed in narrowing sections even though stereoscopic depth information was provided. If object-based depth information (stereo, occlusion, constant average object size) is added, the confusion between narrowing and acceleration still remains but may be slightly reduced. All experiments are consistent with a simple matched filter algorithm for ego-motion detection, neglecting both parallactic and stereoscopic depth information, but leave open the possibility of cue combination at a later stage.

show abstract

Simulation of Driving in Low-Visibility Conditions: Does Stereopsis Improve Speed Perception?

Cited by 18 publications

References 59 publications

Low perceptual sensitivity to altered video speed in viewing a soccer match

Low perceptual sensitivity to altered video speed in viewing a soccer match

Blind haste: As light decreases, speeding increases

The perception of ego-motion change in environments with varying depth: Interaction of stereo and optic flow

Contact Info

Product

Resources

About