Environment width robustly influences egocentric distance judgments

Abstract

Past work has suggested that perception of object distances in natural scenes depends on the environmental surroundings, even when the physical object distance remains constant. The cue bases for such effects remain unclear and are difficult to study systematically in real-world settings, given the challenges in manipulating large environmental features reliably and efficiently. Here, we used rendered scenes and crowdsourced data collection to address these challenges. In 4 experiments involving 452 participants, we investigated the effect of room width and depth on egocentric distance judgments. Targets were placed at distances of 2–37 meters in rendered rooms that varied in width (1.5–40 meters) and depth (6–40 meters). We found large and reliable effects of room width: Average judgments for the farthest targets in a 40-meter-wide room were between 16–33% larger than for the same target distances seen in a 1.5-meter-wide hallway. Egocentric distance cues and focal length were constant across room widths, highlighting the role of environmental context in judging distances in natural scenes. Obscuring the fine-grained ground texture, per se, is not primarily responsible for the width effect, nor does linear perspective play a strong role. However, distance judgments tended to decrease when doors and/or walls obscured more distant regions of the scene. We discuss how environmental features may be used to calibrate relative distance cues for egocentric distance judgments.

Spatial representations of natural scene images generalize across individuals, tasks, and viewing time

“…There is also evidence that the size of the environment, which can be approximated by the surface area of the ground plane, can impact egocentric distance judgments in the real-world [41][42][43] . Variations in the size of the space are also likely related to other cues (e.g., the number of familiar sized objects, boundary visibility) 44 , making the area of the ground plane a good starting point for understanding how pictorial cues may bias spatial representations.…”

“…The Kinect v2 sensor is accurate up to 5 meters and is the most accurate on the midline, which is where our targets were placed. There is some evidence that the size or shape of the environment can have an influence on spatial judgments [41][42][43][44] . Future work therefore should use higher fidelity depth cameras that can capture larger spaces to test whether our findings generalize.…”

Perceiving distance in virtual reality: theoretical insights from contemporary technologies

“…by the end of a hallway) than in unbounded contexts, such as an outdoor open space [ 116 ]. Recent work with virtual reality scenes presented on desktop displays found that increasing room width resulted in participants giving greater distance estimates compared to the same distance shown in a more narrow room [ 117 ]. With a series of experiments, Houck et al [ 117 ] suggested that occlusion of either near or farther parts of the scene related to shorter distance estimations.…”

“…Recent work with virtual reality scenes presented on desktop displays found that increasing room width resulted in participants giving greater distance estimates compared to the same distance shown in a more narrow room [ 117 ]. With a series of experiments, Houck et al [ 117 ] suggested that occlusion of either near or farther parts of the scene related to shorter distance estimations. However, this work was done with screen-based images, rather than in a HMD, so underestimation of distance could also have been owing to a misperception of eyeheight in the scene.…”

“…For example, observers could experience the full wide FOV of the HMD and an artificially restricted FOV with either the presence or absence of their avatar body standing on the virtual ground while judging distances. Other approaches could examine the different types of wide and narrow environments like those used in Houck et al [ 117 ], but with variation in HMD FOV to test whether environmental context manipulations have comparable effects to or interact with FOV manipulations.…”