Naturalistic depth perception and binocular vision

Humans continuously move both their eyes to redirect their foveae to objects at new depths. To correctly execute these complex combinations of saccades, vergence eye movements and accommodation changes, the visual system makes use of multiple sources of depth information, including binocular disparity and defocus. Furthermore, during development, both fine-tuning of oculomotor control as well as correct eye growth are likely driven by complex interactions between eye movements, accommodation, and the distributions of defocus and depth information across the retina. I have employed photographs of natural scenes taken with a commercial plenoptic camera to examine depth perception while varying perspective, blur and binocular disparity. Using a gaze contingent display with these natural images, I have shown that disparity and peripheral blur interact to modify eye movements and facilitate binocular fusion. By decoupling visual feedback for each eye, I have found it possible to induces both conjugate and disconjugate changes in saccadic adaptation, which helps us understand to what degree the eyes can be individually controlled. To understand the aetiology of myopia, I have developed geometric models of emmetropic and myopic eye shape, from which I have derived psychophysically testable predictions about visual function. I have then tested the myopic against the emmetropic visual system and have found that some aspects of visual function decrease in the periphery at a faster rate in best-corrected myopic observers than in emmetropes. To study the effects of different depth cues on visual development, I have investigated accommodation response and sensitivity to blur in normal and myopic subjects. This body of work furthers our understanding of oculomotor control and 3D perception, has applied implications regarding discomfort in the use of virtual reality, and provides clinically relevant insights regarding the development of refractive error and potential approaches to prevent incorrect emmetropization

Towards Everyday Virtual Reality through Eye Tracking

Durch Entwicklungen in den Bereichen Computergrafik, Hardwaretechnologie, Perception Engineering und Mensch-Computer Interaktion, werden Virtual Reality und virtuelle Umgebungen immer mehr in unser tägliches Leben integriert. Head-Mounted Displays werden jedoch im Vergleich zu anderen mobilen Geräten, wie Smartphones und Smartwatches, noch nicht so häufig genutzt. Mit zunehmender Nutzung dieser Technologie und der Gewöhnung von Menschen an virtuelle Anwendungsszenarien ist es wahrscheinlich, dass in naher Zukunft ein alltägliches Virtual-Reality-Paradigma realisiert wird. Im Hinblick auf die Kombination von alltäglicher Virtual Reality und Head-Mounted-Displays, ist Eye Tracking eine neue Technologie, die es ermöglicht, menschliches Verhalten in Echtzeit und nicht-intrusiv zu messen. Bevor diese Technologien in großem Umfang im Alltag eingesetzt werden können, müssen jedoch noch zahlreiche Aspekte genauer erforscht werden. Zunächst sollten Aufmerksamkeits- und Kognitionsmodelle in Alltagsszenarien genau verstanden werden. Des Weiteren sind Maßnahmen zur Wahrung der Privatsphäre notwendig, da die Augen mit visuellen biometrischen Indikatoren assoziiert sind. Zuletzt sollten anstelle von Studien oder Anwendungen, die sich auf eine begrenzte Anzahl menschlicher Teilnehmer mit relativ homogenen Merkmalen stützen, Protokolle und Anwendungsfälle für eine bessere Zugänglichkeit dieser Technologie von wesentlicher Bedeutung sein. In dieser Arbeit wurde unter Berücksichtigung der oben genannten Punkte ein bedeutender wissenschaftlicher Vorstoß mit drei zentralen Forschungsbeiträgen in Richtung alltäglicher Virtual Reality unternommen. Menschliche visuelle Aufmerksamkeit und Kognition innerhalb von Virtual Reality wurden in zwei unterschiedlichen Bereichen, Bildung und Autofahren, erforscht. Die Forschung im Bildungsbereich konzentrierte sich auf die Auswirkungen verschiedener Manipulationen im Klassenraum auf das menschliche Sehverhalten, während die Forschung im Bereich des Autofahrens auf sicherheitsrelevante Fragen und Blickführung abzielte. Die Nutzerstudien in beiden Bereichen zeigen, dass Blickbewegungen signifikante Implikationen für diese alltäglichen Situationen haben. Der zweite wesentliche Beitrag fokussiert sich auf Privatsphäre bewahrendes Eye Tracking für Blickbewegungsdaten von Head-Mounted Displays. Dies beinhaltet Differential Privacy, welche zeitliche Korrelationen von Blickbewegungssignalen berücksichtigt und Privatsphäre wahrende Blickschätzung durch Verwendung eines auf randomisiertem Encoding basierenden Frameworks, welches Augenreferenzunkte verwendet. Die Ergebnisse beider Arbeiten zeigen, dass die Wahrung der Privatsphäre möglich ist und gleichzeitig der Nutzen in einem akzeptablen Bereich bleibt. Wenngleich es bisher nur wenig Forschung zu diesem Aspekt von Eye Tracking gibt, ist weitere Forschung notwendig, um den alltäglichen Gebrauch von Virtual Reality zu ermöglichen. Als letzter signifikanter Beitrag, wurde ein Blockchain- und Smart Contract-basiertes Protokoll zur Eye Tracking Datenerhebung für Virtual Reality vorgeschlagen, um Virtual Reality besser zugänglich zu machen. Die Ergebnisse liefern wertvolle Erkenntnisse für alltägliche Nutzung von Virtual Reality und treiben den aktuellen Stand der Forschung in mehrere Richtungen voran.With developments in computer graphics, hardware technology, perception engineering, and human-computer interaction, virtual reality and virtual environments are becoming more integrated into our daily lives. Head-mounted displays, however, are still not used as frequently as other mobile devices such as smart phones and watches. With increased usage of this technology and the acclimation of humans to virtual application scenarios, it is possible that in the near future an everyday virtual reality paradigm will be realized. When considering the marriage of everyday virtual reality and head-mounted displays, eye tracking is an emerging technology that helps to assess human behaviors in a real time and non-intrusive way. Still, multiple aspects need to be researched before these technologies become widely available in daily life. Firstly, attention and cognition models in everyday scenarios should be thoroughly understood. Secondly, as eyes are related to visual biometrics, privacy preserving methodologies are necessary. Lastly, instead of studies or applications utilizing limited human participants with relatively homogeneous characteristics, protocols and use-cases for making such technology more accessible should be essential. In this work, taking the aforementioned points into account, a significant scientific push towards everyday virtual reality has been completed with three main research contributions. Human visual attention and cognition have been researched in virtual reality in two different domains, including education and driving. Research in the education domain has focused on the effects of different classroom manipulations on human visual behaviors, whereas research in the driving domain has targeted safety related issues and gaze-guidance. The user studies in both domains show that eye movements offer significant implications for these everyday setups. The second substantial contribution focuses on privacy preserving eye tracking for the eye movement data that is gathered from head-mounted displays. This includes differential privacy, taking temporal correlations of eye movement signals into account, and privacy preserving gaze estimation task by utilizing a randomized encoding-based framework that uses eye landmarks. The results of both works have indicated that privacy considerations are possible by keeping utility in a reasonable range. Even though few works have focused on this aspect of eye tracking until now, more research is necessary to support everyday virtual reality. As a final significant contribution, a blockchain- and smart contract-based eye tracking data collection protocol for virtual reality is proposed to make virtual reality more accessible. The findings present valuable insights for everyday virtual reality and advance the state-of-the-art in several directions

I spy with my military eye :strategies of military vision and their use in fine art practice

PhD ThesisThis research deals with specific aspects of the relationship between artistic and military practices through military vision and visioning technologies, and explores these both within and through a fine art practice. In particular, it examines their impact on subjectivity and objectivity, and how these can be analyzed and synthesized through fine art practice. The research indicates that art practice may be the most useful method of critiquing militarism, as a result of its acknowledgment and embrace of shifting positions. The thesis comprises two sections running concurrently on recto and verso pages, in a layout that echoes the constant dialogue of theory and practice. The thesis is conceived as a ‘serious game’ in itself, and the methodology of game playing, shifting identities, provocations and interruptions (all of which constitute the foundation of fieldcraft, particularly the skills of camouflage) is visible throughout. The authorial voice slips from the academic to the conversational as the subjectivity of the researcher becomes evident in the text. The verso section consists of three main chapters, all of which examine subjectivity and objectivity through their respective frameworks and through the prism of practice. It surveys weaponry, devices and strategies created for the purpose of looking. It traces the military intention at the heart of apparently unrelated technologies, and defines four interpretive regimes emerging from these correspondences

Investigating the visual tasks of pedestrians and how one of these tasks, obstacle detection, is influenced by lighting

Current guidelines for pedestrian road lighting are not based on empirical evidence. One approach to providing suitable evidence is to examine the effect of lighting on the visual tasks of pedestrians. This first requires an understanding of what these visual tasks are. An eye-tracking study was carried out in which pedestrians walked a real, outdoor route during the day and after-dark. A novel dual-task method was used to identify the critical visual tasks of the pedestrians. Reaction times to a concurrent audio response task were used to indicate instances when attention may have been diverted towards something significant in the visual environment. Analysis of the eye-tracking videos at these critical times found that the path and other people were the two most significant items looked at. Observation of the path is important for detection and avoidance of obstacles and trip hazards. Good road lighting should therefore facilitate obstacle detection. An obstacle detection experiment was therefore carried out examining the effect of illuminance and Scotopic/Photopic (S/P) ratio on obstacle detection. The experiment improved the realism and ecological validity of previous research by introducing a dynamic fixation target, realistic apparatus scales and real walking (on a treadmill) whilst carrying out an obstacle detection task. Results showed that obstacle detection only improved with illuminance increases up to 2.0 lux. A higher S/P ratio (2.0) provided better detection performance than a low S/P ratio (1.2), but only at the lowest illuminance used of 0.2 lux. The data is used to discuss optimal design criteria for pedestrian road lighting based on obstacle detection. However, other purposes of road lighting, such as creating a feeling of reassurance and enabling accurate interpersonal judgements to be carried out, should also be considered when designing pedestrian road lighting

3D Design Review Systems in Immersive Environments

Design reviews play a crucial role in the development process, ensuring the quality and effectiveness of designs in various industries. However, traditional design review methods face challenges in effectively understanding and communicating complex 3D models. Immersive technologies, particularly Head-Mounted Displays (HMDs), offer new opportunities to enhance the design review process. In this thesis, we investigate using immersive environments, specifically HMDs, for 3D design reviews. We begin with a systematic literature review to understand the current state of employing HMDs in industry for design reviews. As part of this review, we utilize a detailed taxonomy from the literature to categorize and analyze existing approaches. Additionally, we present four iterations of an immersive design review system developed during my industry experience. Two of these iterations are evaluated through case studies involving domain experts, including engineers, designers, and clients. A formal semi-structured focus group is conducted to gain further insights into traditional design review practices. The outcomes of these evaluations and the focus group discussions are thoroughly discussed. Based on the literature review and the focus group findings, we uncover a new challenge associated with using HMDs in immersive design reviews—asynchronous and remote collaboration. Unlike traditional design reviews, where participants view the same section on a shared screen, HMDs allow independent exploration of areas of interest, leading to a shift from synchronous to asynchronous communication. Consequently, important feedback may be missed as the lead designer disconnects from the users' perspectives. To address this challenge, we collaborate with a domain expert to develop a prototype that utilizes heatmap visualization to display 3D gaze data distribution. This prototype enables lead designers to quickly identify areas of review and missed regions. The study incorporates the Design Critique approach and provides valuable insights into different heatmap visualization variants (top view projection, object-based, and volume-based). Furthermore, a list of well-defined requirements is outlined for future spatio-temporal visualization applications aimed at integrating into existing workflows. Overall, this thesis contributes to the understanding and improvement of immersive design review systems, particularly in the context of utilizing HMDs. It offers insights into the current state of employing HMDs for design reviews, utilizes a taxonomy from the literature to analyze existing approaches, highlights challenges associated with asynchronous collaboration, and proposes a prototype solution with heatmap visualization to address the identified challenge

The Workshop as Art: Insight Into the Subjective Experience of Perceptual Illusion Through an Expanded Art Practice

This thesis documents and analyses the development of a series of artistic workshops based on re-creations of scientific experiments which explore the subjective experiences of perceptual illusions. It explains how reflections on expanded art practice led to a re-positioning of the workshop as art, in effect re-framing the scientific experiments performed within the workshop as part of a co-creative artistic experience. I argue that this shift in perspective had transformative effects on the experience of the workshop (for both practitioner and participant), which renders a utility and significance for the workshop beyond educational research or as an engagement tool. This investigation uses a mixed-methods approach, which combines artistic research with experimental psychology. The workshops were based on multisensory perceptual illusions, which employ combinations of tactile, sonic, and visual stimulation. Specifically, three experimental models were used: the 'rubber hand', 'Ganzfeld', and 'strange face' illusions which are studied widely in experimental psychology. A key challenge of this research was to capture the subjective experiences of subtle sensory phenomena that exist at the limit of perception. In light of this, a theoretical framework encompassing practical aspects of mindful practice to enhance self-awareness is developed. This thesis provides an in-depth exploration of participants subjective perceptual experiences and shows how they informed the development of three new limited-edition workshops. The thesis articulates emergent findings and benefits that are of value to both scientists and artists. These include reflections on the performative roles of participants within the workshop (which led to a re-positioning of the 'workshop as art'), and new experiments that raise important questions relating to the role of imagination and sensory suggestibility in perceptual illusion. The documentation of the workshops and the resources (instructions and scores) required to re-create them, are presented as an online exhibition supporting this thesis. The research provides new knowledge and a much needed transferable framework of practice for artists and researchers working in the field of science art collaboration, transdisciplinary practice

On the popularization of digital close-range photogrammetry: a handbook for new users.

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Γεωπληροφορική

Yale Medicine : Alumni Bulletin of the School of Medicine, Autumn 2008- Spring 2009

This volume contains Yale Medicine: alumni bulletin of the School of Medicine, v.43 (Autumn 2008-Spring 2009). Prepared in cooperation with the alumni and development offices at the School of Medicine. Earlier volumes are called Yale School of Medicine alumni bulletins, dating from v.1 (1953) through v.13 (1965). Digitized with funding from the Arcadia fund, 2017.https://elischolar.library.yale.edu/yale_med_alumni_newsletters/1024/thumbnail.jp

Proceedings of the 21st International Congress of Aesthetics, Possible Worlds of Contemporary Aesthetics Aesthetics Between History, Geography and Media

The Faculty of Architecture, University of Belgrade and the Society for Aesthetics of Architecture and Visual Arts of Serbia (DEAVUS) are proud to be able to organize the 21st ICA Congress on “Possible Worlds of Contemporary Aesthetics: Aesthetics Between History, Geography and Media”. We are proud to announce that we received over 500 submissions from 56 countries, which makes this Congress the greatest gathering of aestheticians in this region in the last 40 years. The ICA 2019 Belgrade aims to map out contemporary aesthetics practices in a vivid dialogue of aestheticians, philosophers, art theorists, architecture theorists, culture theorists, media theorists, artists, media entrepreneurs, architects, cultural activists and researchers in the fields of humanities and social sciences. More precisely, the goal is to map the possible worlds of contemporary aesthetics in Europe, Asia, North and South America, Africa and Australia. The idea is to show, interpret and map the unity and diverseness in aesthetic thought, expression, research, and philosophies on our shared planet. Our goal is to promote a dialogue concerning aesthetics in those parts of the world that have not been involved with the work of the International Association for Aesthetics to this day. Global dialogue, understanding and cooperation are what we aim to achieve. That said, the 21st ICA is the first Congress to highlight the aesthetic issues of marginalised regions that have not been fully involved in the work of the IAA. This will be accomplished, among others, via thematic round tables discussing contemporary aesthetics in East Africa and South America. Today, aesthetics is recognized as an important philosophical, theoretical and even scientific discipline that aims at interpreting the complexity of phenomena in our contemporary world. People rather talk about possible worlds or possible aesthetic regimes rather than a unique and consistent philosophical, scientific or theoretical discipline