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Perceiving layout and knowing distances: The interaction, relative potency, and contextual use of different information about depth

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Abstract

The layout in most natural environments can be perceived through the use of nine or more sources of information. This number is greater than that available for the perception of any other property in any modality of perception. Oddly enough, how perceivers select and/or combine them has been relatively unstudied. This chapter focuses briefly on the issues inhibiting its study, and on what is known about integration, then in detail on an assessment of nine sources of information—occlusion, relative size, relative density, height in the visual field, aerial perspective, motion perspective, binocular disparities, convergence, and accommodation— and their relative utility at different distances. From a comparison of their ordinal depth-threshold functions, we postulate three different classes of distance around an observer--personal space, action space, and vista space. Within each space, we suggest a smaller number of sources act in consort, with different relative strengths, in offering the perceiver information about layout. We then apply this system to the study of representations of layout in art, to the development of the perception of layout by infants, and to an assessment of the scientific study of layout.
... for centuries, what is commonly known as the problem of depth perception (Cutting & Vishton, 1995). How can we possibly see three dimensions if our retina only has two dimensions? ...
... The mainstream stance in the study of vision is that our brain reconstructs depth, the dimension that was lost in the retinal image, aided by a series of depth cues (Cutting & Vishton, 1995). Some examples of depth cues are stereopsis (i.e., our two eyes provide us with overlapping but different perspectives), retinal image size (i.e., farther things appear smaller in the retinal image than closer things), or occlusion (i.e., when a surface visually blocks a second surface, the first must be closer to us than the second). ...
Thesis
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This dissertation looks at the psychological effects of the breathing camera, a type of camera optic flow (i.e., camera movement) that specifies a human observer quietly breathing. Drawing from J. J. Gibson’s (1979) ecological approach to perception, two key optical characteristics of the breathing camera are identified and manipulated to probe the influence of natural perception on mediated perception. The first, exteroceptive characteristic is the translation of the point of observation, which makes available depth information of the surroundings through global optic flow. The second characteristic is that the camera proprioceptively specifies a human observer by engaging in human-like events. The breathing camera is an immersive perceptual device that should increase the engagement of the viewer with the narrative. The contributions of the two optical characteristics to the breathing camera effects are experimentally tested with three conditions: a real breathing camera condition where both types of information are available, a fake breathing camera condition where only human-like proprioception is available, and a no camera flow condition where both types of information are absent. Two separate sets of stimuli were used for the experimental comparison. The first was a homemade set with 6 video messages filmed documentary-style where camera condition was a within-video variable. The second was a fiction set with 24 video messages extracted from dramatic and comedic serial narratives where camera condition was a between-video variable for the comparisons with the real camera. A combination of psychophysiological and self-reported methods were used to measure the effect of the breathing camera on the emotional and attentional responses of the viewer. The real motion camera was found to elicit higher physiological arousal than the other two cameras, indicating a stronger emotional response, and it was found to be equivalent to the no camera flow condition otherwise. The fake breathing camera was found to be the least effective condition, as shown by lower attention levels and less emotional responses than both the real breathing camera and than no camera flow. This was primarily confirmed by the physiological variables in the homemade set, and by the self-reported variables in the fiction set.
... As a measurement of the quality of stereovision, patients achieved a mean category of 6 (≙ 100''; SD: 3) in the Circles test and HS a mean category of 7 (≙ 80''; SD: 3). Ceiling effects were found for spatial localization / visuoconstruction in HS, who reached a median score of 50 points (IQR: [49][50] in the VOSP test battery. Stereovision did not affect spatial perception of HS, as there was no signi cant difference in the VOSP result between HS with intact and impaired stereovision (z VOSPsum = -1. ...
... However, the difference in distance of objects from the observer (which was 4 cm or less) was below the threshold that could be detected by the interpretation of the objects' size as a monocular depth cue. According to Cutting et al., relative size of similar objects facilitates the discrimination of distances between objects in a range of at least 2.7% of their distance from the observer (50). In the SPiAR study, holograms were projected at a distance of 1.5 m, thus two objects have to lie at least 4.3 cm (2.7% of 1.5 m) apart from each other in order to successfully discriminate their distance based on object size. ...
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Background Augmented Reality (AR)-based interventions are applied in neurorehabilitation with increasing frequency. Depth perception is required for the intended interaction within AR environments. Until now, however, it is unclear whether patients after stroke with impaired visuospatial perception (VSP) are able to perceive depth in the AR environment. Methods Different aspects of VSP (stereovision and spatial localization / visuoconstruction) were assessed in 20 patients after stroke (mean age: 64 ± 14 years) and 20 healthy subjects (HS, mean age: 28 ± 8 years) using clinical tests. The group of HS was recruited to assess the validity of the developed AR tasks in testing stereovision. To measure perception of holographic objects, three distance judgment tasks and one three-dimensionality task were designed. The effect of impaired stereovision on performance in each AR task was analyzed. AR task performance was modeled by aspects of VSP using separate regression analyses for HS and for patients. Results In HS, stereovision had a significant effect on the performance in all AR distance judgment tasks (p = .021, p = .002, p = .046) and in the three-dimensionality task (p = .003). Individual quality of stereovision significantly predicted the accuracy in each distance judgment task and was highly related to the ability to perceive holograms as three-dimensional (p = .001). In stroke-survivors, impaired stereovision had a specific deterioration effect on only one distance judgment task (p = .042), whereas the three-dimensionality task was unaffected (p = .317). Regression analyses confirmed a lacking impact of patients’ quality of stereovision on AR task performance, while spatial localization / visuoconstruction significantly prognosticated the accuracy in distance estimation of geometric objects in two AR tasks. Conclusion Impairments in VSP reduce the ability to estimate distance and to perceive three-dimensionality in an AR environment. While stereovision is key for task performance in HS, spatial localization / visuoconstruction is predominant in patients. Since impairments in VSP are present after stroke, these findings might be crucial when AR is applied for neurorehabilitative treatment. In order to maximize the therapy outcome, the design of AR games should be adapted to patients’ impaired VSP. Trial registration The trial was not registered, as it was an observational study.
... Potential applications can be as diverse as object manipulation in robotics [2] or collision avoidance for autonomous vehicles during navigation [3]. In humans, depth processing is extremely well developed and relies on monocular (e.g., occlusions, perspectives or motion parallax) and binocular (retinal disparities) visual cues [4]. This processing consumes very little energy as the visual system encodes retinal information under the form of action potentials, or spikes and it is believed that the brain only requires about 20 Watts to function [5]. ...
Article
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Depth estimation is an important computer vision task, useful in particular for navigation in autonomous vehicles, or for object manipulation in robotics. Here, we propose to solve it using StereoSpike , an end-to-end neuromorphic approach, combining two event-based cameras and a Spiking Neural Network (SNN) with a modified U-Net-like encoder-decoder architecture. More specifically, we used the Multi Vehicle Stereo Event Camera Dataset (MVSEC). It provides a depth ground-truth, which was used to train StereoSpike in a supervised manner, using surrogate gradient descent. We propose a novel readout paradigm to obtain a dense analog prediction –the depth of each pixel– from the spikes of the decoder. We demonstrate that this architecture generalizes very well, even better than its non-spiking counterparts, leading to near state-of-the-art test accuracy. To the best of our knowledge, it is the first time that such a large-scale regression problem is solved by a fully spiking neural network. Finally, we show that very low firing rates (<5%) can be obtained via regularization, with a minimal cost in accuracy. This means that StereoSpike could be efficiently implemented on neuromorphic chips, opening the door for low power and real time embedded systems.
... Among other things, the bias can be attributed to the intensification of the aerial perspective resulting from the distance-dependent changes of color and contrast. Moreover, the height of an object in the visual field can serve as a cue to distance (Cutting & Vishton, 1995). As the color of the horizon and distant environment became more similar under foggy conditions in our scenes, the horizon may have been misplaced and perceived as being lower. ...
Article
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It is well known in the psychophysical literature that low visual contrasts can lead observers to misestimate the speed of moving objects. This effect can have important consequences for traffic safety when navigating under low visibility due to adverse weather conditions (e.g., fog) or visual impairments. So far, road traffic research has primarily focused on the perception of self-motion during driving showing that drivers can both under-and overestimate their own driving speed depending on the spatial distribution of contrast. In two experiments, we used a two-interval forced choice discrimination task to investigate whether pedestrians would be subject to similar biases when estimating the speed of approaching vehicles in a simulated traffic scene. We found that the perceived vehicle speed decreased when the contrast of the view was reduced uniformly but increased when contrast was reduced in a distance-dependent manner, simulating more realistically visibility in fog. The increase of the perceived vehicle speed in simulated fog occurred in bare and visually more complex road environments including either roadside trees or road markings. The origins of such misperceptions, specifically in fog, remain unclear. The temporal integration of motion signals in combination with a lack in speed constancy, and the illusion of acceleration due to the dynamic contrast-change of the vehicle constitute potential explanations that need further investigation.
... Moreover, participants also performed a distance estimation task following the same experimental paradigm to control for possible perceptual distortions due to arousal and fatigue. Spatial representation can be modulated by arousal (Witt and Proffitt, 2005;Witt et al., 2008;Shiban et al., 2016), emotions (Stefanucci and Storbeck, 2009;Storbeck and Stefanucci, 2014;Cañal-Bruland et al., 2015), or action intentionality (Cutting and Vishton, 1995;Bhalla and Proffitt, 1999) but seems to be unaffected by GABAergic and dopaminergic modulation (Leonte et al., 2018). Therefore, we hypothesize that a genuine effect of physical exercise would be specific to time and not space perception, while arousal would have a generic impact on both perceptual domains. ...
Article
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Moderate physical activity can influence cognitive functions and visual cortical activity. However, little is known about the effects of exercise on fundamental perceptual domains, such as spatial and temporal representation. Here we tackled this issue by testing the impact of physical activity on a temporal estimation task in a group of adult volunteers in three different conditions: (1) in a resting condition (baseline), (2) during moderate physical activity (cycling in place – PA), and (3) approximately 15 to 20 min following the physical activity phase, in which participants were seated and returned to a regular heart rate (POST). We show that physical activity specifically impacts time perception, inducing a consistent overestimation for durations in the range of milliseconds. Notably, the effect persisted in the POST session, ruling out the main contribution of either heart rate or cycling rhythmicity. In a control experiment, we found that spatial perception (distance estimation) was unaffected by physical activity, ruling out a major contribution of arousal and fatigue to the observed temporal distortion. We speculate that physical exercise might alter temporal estimation either by up-regulating the dopaminergic system or modulating GABAergic inhibition.
... Consequently, our X-ray vision system mimics a physical window. It provides non-pictorial depth cues such as motion parallax (changes in the perspectives of stationary objects with self-motion) and binocular disparity (slightly different visual images in each eye due to their horizontal separation) typically available in real-world environments [2]. This allows users to move and still naturally see through physical occlusions (such as real walls, created by the scene understanding observer) as if looking through a window in the real-world. ...
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X-ray vision, a technique that allows users to see through walls and other obstacles, is a popular technique for Augmented Reality (AR) and Mixed Reality (MR). In this paper, we demonstrate a dynamic X-ray vision window that is rendered in real-time based on the user's current position and changes with movement in the physical environment. Moreover, the location and transparency of the window are also dynamically rendered based on the user's eye gaze. We build this X-ray vision window for a current state-of-the-art MR Head-Mounted Device (HMD) -- HoloLens 2 by integrating several different features: scene understanding, eye tracking, and clipping primitive.
Thesis
1.1 Hintergrund und Ziele Visuelle Wahrnehmung scheint für den Menschen eine der wichtigsten und bedeutendsten bewussten Quellen zu sein, um Informationen über ihre Umwelt zu erhalten und zu erfahren. Neben der Sehschärfe kann die räumliche Tiefenwahrnehmung im Alltag oder auch im Hochleistungssport eine beachtliche Rolle spielen 1. Die Qualität der Tiefenwahrnehmung wird durch binokulare und monokulare optische Hinweise beeinflusst 2-4. Beim Binokularsehen, oder auch Stereosehen genannt, bekommt das Gehirn, bei Fokussierung eines Objektes, aufgrund der unterschiedlichen Position der Augen, zwei Bilder mit verschiedenen Blickwinkeln 5. Durch kortikale Fusion dieser beiden Bilder kann eine Form der Tiefenwahrnehmung entstehen. Quantifiziert wird das Stereosehen unter anderem durch die Stereosehschärfe. Dies ist der kleinste noch erkannte Distanzunterschied zweier Objekte, der zu einer räumlichen Tiefenwahrnehmung führt, gemessen in Bogensekunden 1. In der vorliegenden Arbeit wurde die Fragestellung untersucht, ob sich das Stereosehen bei Sportlern mit bereits guter Stereosehschärfe durch ein digitales binokulares Sehtraining noch verbessern kann. 1.2 Methoden Zur Messung der Stereosehschärfe existieren einige Testmethoden, die sich im Aufbau, Ablauf und der Darstellungsmethode unterscheiden. In der vorliegenden Studie wurde der c-Digital Vision Trainer® verwendet. Hierbei wurden einem Probanden auf einem polarisierten 3D-Fernsehgerät verschiedene Stimuli mit unterschiedlichem Schwierigkeitsgrad zur Erkennung präsentiert. Insgesamt 31 männliche und weibliche Sportler aus dem Bereich Tennis (darunter Tennisprofis, Jungprofis/Jugendspieler, ehemalige Profis und Trainer) absolvierten an der Tennisbase des Bayerischen und Deutschen Tennisverbandes in Oberhaching innerhalb von 6 Wochen mindestens 6 Trainingseinheiten mit je 192 stereoskopischen Einzeltests mit variablem Schwierigkeitsgrad von 15 -300 Bogensekunden (insgesamt 6 Stufen: 15, 30, 45, 60, 150, 300 Bogensekunden). Gemessen wurde die Stereosehschärfe in Bogensekunden bzw. der Stereogrenzwinkel („Kleinster Stereowinkel, bei dem noch Stereopsis vorhanden ist “)6, die Reaktionszeit in ms und die Sicherheit bzw. Korrektheit der Antworten in %. Die Trainingsstimuli waren dynamischer Natur mit sich bewegenden Bällen. Im statischen Test, zur Überprüfung des Trainingserfolges, wurden weiße Scheiben ohne Rotation und Textur auf grauem Hintergrund präsentiert. Zur Vermeidung der Messung von motorischen Trainingseffekten wurde der Parameter „ReSt“ (Reaktionszeitzuwachs pro Stereodisparitätsabnahme) geschaffen. Unter der Annahme, dass der Zeitanteil für die motorische Reaktionszeit bei variierenden Disparitätsstufen gleich groß ist, stellt der Reaktionszeitzuwachs pro zunehmenden Schwierigkeitsgrad dasjenige Zeitintervall dar, das für das visuelle System nötig ist, um den stereoskopischen Schwierigkeitszuwachs (von 45 Bogensekunden zu 15 Bogensekunden) zu bewältigen. 1 1.3 Ergebnisse und Beobachtungen Vor dem Training erreichten 74 % der Sportler einen Stereogrenzwinkel von 15 oder 30 Bogensekunden, nach dem Training 93,5 %. 41,9 % verbesserten sich um min. eine Stufe, 12,9 % von allen sogar um insgesamt drei Stufen. N = 13 von 15 (87 %) Probanden, die in der Eingangsmessung einen Stereogrenzwinkel von 30 Bogensekunden oder schlechter aufwiesen, zeigten eine Verbesserung um mindestens eine Stufe. Die mittlere Reaktionszeit verlängerte sich signifikant mit Zunahme des Schwierigkeitsgrades. Die Reaktionszeit bei Stimuli von 15 Bogensekunden verkürzte sich durch das Sehtraining im Mittel signifikant von 3,9 s auf 1,6 s (59 %). Auch der „ReSt“ verminderte sich durch das Training signifikant von 1,6 s auf 0,5 s (67 %). 83,9 % der Probanden konnten ihre individuelle „ReSt“ verbessern (darunter 61,9 % um über 1000 ms). Die Korrektheit der Versuche bei 30 Bogensekunden steigerte sich im Mittel signifikant um 23 %. 1 1.4 Schlussfolgerungen und Diskussion Durch das digitale Sehtraining konnten die Probanden ihr stereoskopisches Sehen signifikant hinsichtlich Stereogrenzwinkel, Reaktionszeit und Korrektheit verbessern. Die beobachtete Verbesserung der Reaktionszeit im Sehtraining führte jedoch nicht zur Abnahme der Korrektheit bei der Beantwortung der visuellen Fragen und stellt damit insgesamt eine Verbesserung der Stereosehfähigkeit dar. Beim Bayerischen und Deutschen Tennisverband wurde zum Zeitpunkt der Durchführung der vorliegenden Studie lediglich die Sehschärfe als Screening-Test bestimmt. Da in dem verwendeten Testsystem vor Studienbeginn die maximal erreichbare Stufe bei 15 Bogensekunden gewählt wurde, war es bei vielen Probanden nicht möglich eine Verbesserung des Stereogrenzwinkels nachzuweisen. Aus diesem Grund wurden Parameter wie Reaktionszeit und Korrektheit geschaffen bzw. bestimmt, um auch hier eine Entwicklung im Stereosehen nachzuweisen. Eine Übertragung des Erfolges im Sehtraining auf die Sportliche Leistung scheint abschließend nicht eindeutig geklärt. Anhand eines Fragebogens, den die Probanden am Ende der vorliegenden Studie durchführten, konnte gezeigt werden, dass sich die Selbsteinschätzung im Sport auch im Ergebnis des Sehtrainings widerspiegelt. In zukünftigen Sehtrainings könnten weitere Anpassungen zum einen am Training, zum anderen auch an der Überprüfung des Trainings erfolgen, um eine sichere Übertragung des Sehtrainings auf den Tennissport zu garantieren.
Chapter
Technological innovations have dramatically altered the role of the pilot from operator-in-control to that of supervisor and monitor of system operations. Recent developments suggest that pilot’s in the near future will be coordinating their actions with multiple intelligent agents, such as drones. These and other innovations require human factors experts to consider the information requirements of the task, what information to display, and how and where to display the information. This chapter reviews the design principles to optimize human interaction with automation, the design of information displays that facilitate the human supervisors understanding of the intention of autonomous systems, and the design of novel head-/helmet mounted displays as an alternative to existing HUD and cockpit LCD displays.
Article
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