Impending Collision Judgment from an Egocentric Perspective in Real and Virtual Environments: A Review

Abstract

The human egocentric perception of approaching objects and the related perceptual processes have been of interest to researchers for several decades. This article gives a literature review on numerous studies that investigated the phenomenon when an object approaches an observer (or the other way around) with the goal to single out factors that influence the perceptual process. A taxonomy of metrics is followed by a breakdown of different experimental measurement methods. Thereinafter, potential factors affecting the judgment of approaching objects are compiled and debated while divided into human factors (e.g., gender, age, and driving experience), compositional factors (e.g., approaching velocity, spatial distance, and observation time), and technical factors (e.g., field of view, stereoscopy, and display contrast). Experimental findings are collated, juxtaposed, and critically discussed. With virtual-reality devices having taken a tremendous developmental leap forward in the past few years, they have been able to gain ground in experimental research. Therefore, special attention in this article is also given to the perception of approaching objects in virtual environments and put in contrast to the perception in reality.

Pedestrians Accept Shorter Distances to Light Vehicles Than Dark Ones When Crossing the Street

“…The variation of the vehicle speed was designed to avoid potential bias of the participants: If the same speed was maintained for all encounters, participants might tend to make their crossing decisions based on a specific spatial distance of the vehicle during its approach. By varying the vehicle speed, participants are obliged to incorporate the perceived speed in their decisions and vary the chosen spatial distance for their TTC choices (see Feldstein & Dyszak, 2020).…”

“…Some relevant factors and parameters that should be considered when setting up a road-crossing experiment that allows for the investigation of our brightness-related hypothesis are summarized in this section. See a detailed literature review of factors and parameters that affect road-crossing decisions in Feldstein (2019).…”

“…Pedestrians have a sensible tendency to err in the direction of safety. An analysis across numerous studies suggests the estimated TTC to be, on average, at about 75% of the actual TTC (Feldstein, 2019).…”

Egocentric Distance Perception: A Comparative Study Investigating Differences Between Real and Virtual Environments

“…The traffic cone was placed on the ground at distances of 8 m, 9 m, 10 m, 11 m, 12 m, and 13 m in pseudorandomized order. All of these distances are within the range of the action space (2–30 m) that requires a different set of depth cues than distances within personal space (< 2 m) or vista space (> 30 m) (see Cutting, 1997; Feldstein, 2019). The distances in our experiment were selected to contrast most of the reported experiments on distance perception, which primarily investigated distances of maximum seven meters.…”

“…A general overview of different depth cues and their effective distance ranges can be found in Feldstein (2019).…”