The task-dependent use of binocular disparity and motion parallax information

Abstract

Binocular disparity and motion parallax are powerful cues to the relative depth between objects. However to recover absolute depth, either additional scaling parameters are required to calibrate the information provided by each cue, or it can be recovered through the combination of information from both cues (Richards, W. (1985). Structure from stereo and motion. Journal of the Optical Society of America, 2, 343-349). However, not all tasks necessarily require a full specification of the absolute depth structure of a scene and so psychophysical performance may vary depending on the amount of information available, and the degree to which absolute depth structure is required. The experiments reported here used three different tasks that varied in the type of geometric information required in order for them to be completed successfully. These included a depth nulling task, a depth-matching task, and an absolute depth judgement (shape) task. Real world stimuli were viewed (i) monocularly with head movements, (ii) binocularly and static, or (iii) binocularly with head movements. No effect of viewing condition was found whereas there was a large effect of task. Performance was accurate on the matching and nulling tasks and much less accurate on the shape task. The fact that the same perceptual distortions were not evident in all tasks suggests that the visual system can switch strategy according to the demands of the particular task. No evidence was found to suggest that the visual system could exploit the simultaneous presence of disparity and motion parallax.

Matching perceived depth from disparity and from velocity: Modeling and psychophysics

“…Some of these experiments have been conducted in the laboratory with computer-generated displays Brenner & Landy, 1999;Brenner & van Damme, 1999;Collett, Schwarz, & Sobel, 1991;Johnston, 1991;Johnston, Cumming, & Landy, 1994;Norman & Todd, 1998;Todd, Oomes, Koenderink, & Kappers, 2001;Tittle, Todd, Perotti, & Norman, 1995), whereas other studies have been carried out by using real objects in fully illuminated natural environments (Baird & Biersdorf, 1967;Battro, Netto, & Rozestraten, 1976;Bradshaw, Parton, & Glennerster, 2000;Cuijpers, Kappers, & Koenderink, 2000a, Cuijpers, Kappers, & Koenderink, 2000bGilinsky, 1951;Harway, 1963;Koenderink, van Doorn, Kappers, & Todd, 2002;Koenderink, van Doorn, & Lappin, 2000;Loomis, Da Silva, Fujita, & Fukusima, 1992;Loomis & Philbeck, 1999;Norman, Crabtree, Clayton, & Norman, 2005;Norman, Lappin, & Norman, 2000;Norman, Todd, Perotti, & Tittle, 1996 -see their Experiment 4). In most of the cases, however, the psychophysical literature suggests that human observers do not estimate the viewing distance correctly.…”

Reaching for virtual objects: binocular disparity, retinal motion and the control of prehension

“…It has long been established that both cues can evoke independently a strong impression of depth structure (1,2) and determine relative depth with immense precision (3) . The degree to which either cue supports veridical judgments of an object's size and depth, however, has been questioned in a recent, well-focused sequence of experiments on depth constancy and shape perception (3)(4)(5)(6)(7)(8)(9)(10)(11) . The general conclusion of these experiments is that depth constancy is considerably less than perfect, perceived shape is distorted and absolute distance is typically misestimated.…”

“…To recover veridical depth structure, initial measurements of horizontal binocular disparity and retinal image motion must be scaled using additional (e.g. extra-retinal) information or, if both cues are available simultaneously, this scaling problem can be avoided as there is sufficient information in the retinal image to determine structure and viewing distance uniquely through the combination of the information that each cue provides (3,10,12,13) . Whether perceptual performance improves when both cues are available simultaneously remains uncertain (3,(14)(15)(16)(17) see also Landy & Brenner (18) for a recent review).…”

Human-Robot Interaction for Semi-Autonomous Assistive Robots : Empirical Studies and an Interaction Concept for Supporting Elderly People at Home

“…Varying results have been obtained on the merits of stereo display in the presence of motionbased cues, with some studies suggestive of merits (Sollenberger & Milgram, 1993;Ware & Franck, 1996;Hubona et al, 2004) and others not (Dosher et al, 1986;Ware et al, 1993;Naepflin & Menozzi, 2001;van Schooten et al, 2010). In addition to the presence of other depth cues, the value of binocular disparity has also shown to depend on such factors as task (Edmondson et al, 2012;Arsenault & Ware, 2004;Bradshaw et al, 2000), distance of the perceived objects (Arsenault & Ware, 2004;Bradshaw et al, 2000;Bradshaw & Glennerster, 2006;Surdick et al, 1997), and orientation of the scene (or perspective of the viewer) (Kim et al, 1987;Fujiwara et al, 2011).…”

“…• Various, partially novel task types: As task is an influential factor (Edmondson et al, 2012;Arsenault & Ware, 2004;Bradshaw et al, 2000), effects may vary according to the task.…”