A Portable Bio-Inspired Architecture for Efficient Robotic Vergence Control

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Empirical and theoretical psychophysiological considerations regarding information processing during skilled reading

Current psychophysiological research regarding eye movements, cortical alpha rhythm, and memory mechanisms is reviewed in light of the role these phenomena may play in the process of skilled reading. A model of perceptual constriction leading to a decrease in reading performance is advanced. The psychological and physical manifestations of perceptual constriction are developed, and are discussed relative to the psychophysiological phenomena mentioned above. An attempt is made to provide a synthetic model of skilled reading and reading difficulties consistent with current theoretical and empirical knowledge. Such a model is useful to optometrists and other professionals interested in learning and reading difficulties

Visual dysfunction : a contributing factor in memory deficits, and therefore learning difficulties?

This thesis is based on Educational Therapy (ET) practice which has found eye muscle imbalance is a key factor to be addressed in management of learning difficulties (LD). This level of oculo-motor (o-m) function is a \u27hidden\u27 handicap as individuals are unaware of the problem; it is not routinely tested; and is not generally included in learning difficulties research. O-m function is omitted in standard paediatric optometry tests, and in school vision screening. Eye exercises increase the range of binocular fields of vision by employing stereopsis glasses and red/green slides. Central vision loss was uncovered when students reported words, seen by only the right eye, disappear or switch on and off . When the left eye was covered, right eye vision returned but was lost again with binocular vision, even though larger shapes on the screen remained complete. In effect, global vision was unaffected while right eye central (foveal) vision was suppressed. This is considered significant because students attending ET have learning difficulties with phonemic memory, spelling and reading deficits, which are predominantly left hemisphere processes. The aim of this three-part study, consisting of School Survey, ET Intervention study and Case studies, was to: a) determine whether o-m dysfunction was found in a girls\u27 school population and/or was associated with LD; b) set up an Intervention study to explore the effects of vision training on the outcomes of a subsequent week-long word-skills programme in the ET practice. Two case studies we\u27re also examined, that of matched senior school boys whose outcomes were significantly different; and c) examine more closely the common pattern of muscle imbalance in two case studies of current junior school students. This tested the therapy assumption that mal-adaptive sensory feedback was contributing to o-m dysfunction. This notion is based on the Luria (1973) Model of Levels of Neural Function which provides the framework for ET practice, and the Developmental Model of LD that has evolved in application and explanation. Part 1 School Survey. This exploratory, cross-sectional study included a randomised sample of 277 participants in a private girl\u27s school. A 7-10 minute screening was provided by five optometrists, with an expanded protocol including o-m function. Also assessed were academic standards of reading comprehension and spelling, reasoning, visual perception, phonological skills, auditory, visual and phonemic memory, and arm dominance. Results showed visual dysfunction and mixed eye dominance in approximately equal numbers. Of the 47% girls with visual dysfunction, not all had literacy problems; however, LD students had corresponding degrees of o-m dysfunction, memory deficit and mixed hand / arm dominance. Part 2 Intervention study. The Research Question for the Intervention Study was: Does the difference in learning standards depend on which eye is disadvantaged in the case of weak binocularity? This question was answered by determining the outcomes to literacy levels once normal binocular o-m function and stable eye dominance were established. Twenty-four students (6 to 18 years) had Behavioural Optometry assessment prior to commencing therapy and were found to have o-m dysfunction, undetected by previous standard optometry tests. Eye exercise results showed 62.5% of the group had changed from left to right eye dominance. The dominance criterion was set by this group, indicated by the right eye holding fixation through full range of fusional reserves (binocular overlap), together with superior eye-tracking speed \u3e20% by the right, compared to the left, eye. Associated significant gains in literacy and phonemic memory were also achieved by the newly established \u27right-eyed\u27 group. In spite of undergoing identical treatment, the \u27left-eyed\u27 group retained limited foveal binocularity, and made less progress in literacy outcomes. Part 3 Two current Case Studies. Present ET practice benefited from insights gained from the 36% \u27unsuccessful\u27 participants of the previous study. Better therapy outcomes are achieved from an integrative motor-sensory approach, supported by Podiatry and Cranial Osteopathy. This detailed study involved two junior school boys who exemplified a common pattern of physical anomalies. For example, RW (8-year old male) had \u27minimal brain damage\u27 and LD that co-occur with unstable feet and o-m control, postural muscle imbalance, poor balance, motor co-ordination and dyspraxia. After 18, two-hour therapy sessions over nine months, he is now reading well, his motor co-ordination, eye tracking and writing are within the ‘low normal range’, and he is interacting competently with his peers. Learning difficulties can be conceptualised as a profile of immaturities. The results of this three part study have shown that once the \u27hidden\u27 handicap of right eye suppression is overcome with balanced binocular fields of vision, learning difficulties arc ameliorated. This is affirmed by the positive gains achieved by these students, not only in literacy skills but also \u27outgrowing\u27 immaturity in motor-sensory-perceptual development

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

Engineering data compendium. Human perception and performance. User's guide

The concept underlying the Engineering Data Compendium was the product of a research and development program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design and military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from the existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by systems designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is the first volume, the User's Guide, containing a description of the program and instructions for its use

Eye movements in the wild : Oculomotor control, gaze behavior & frames of reference

Understanding the brain's capacity to encode complex visual information from a scene and to transform it into a coherent perception of 3D space and into well-coordinated motor commands are among the outstanding questions in the study of integrative brain function. Eye movement methodologies have allowed us to begin addressing these questions in increasingly naturalistic tasks, where eye and body movements are ubiquitous and, therefore, the applicability of most traditional neuroscience methods restricted. This review explores foundational issues in (1) how oculomotor and motor control in lab experiments extrapolates into more complex settings and (2) how real-world gaze behavior in turn decomposes into more elementary eye movement patterns. We review the received typology of oculomotor patterns in laboratory tasks, and how they map onto naturalistic gaze behavior (or not). We discuss the multiple coordinate systems needed to represent visual gaze strategies, how the choice of reference frame affects the description of eye movements, and the related but conceptually distinct issue of coordinate transformations between internal representations within the brain.Peer reviewe

A computational model of space-variant vision based on a self-organised artificial retina tessellation

Abstract available: p.i-iii

How to improve learning from video, using an eye tracker

The initial trigger of this research about learning from video was the availability of log files from users of video material. Video modality is seen as attractive as it is associated with the relaxed mood of watching TV. The experiments in this research have the goal to gain more insight in viewing patterns of students when viewing video. Students received an awareness instruction about the use of possible alternative viewing behaviors to see whether this would enhance their learning effects. We found that: - the learning effects of students with a narrow viewing repertoire were less than the learning effects of students with a broad viewing repertoire or strategic viewers. - students with some basic knowledge of the topics covered in the videos benefited most from the use of possible alternative viewing behaviors and students with low prior knowledge benefited the least. - the knowledge gain of students with low prior knowledge disappeared after a few weeks; knowledge construction seems worse when doing two things at the same time. - media players could offer more options to help students with their search for the content they want to view again. - there was no correlation between pervasive personality traits and viewing behavior of students. The right use of video in higher education will lead to students and teachers that are more aware of their learning and teaching behavior, to better videos, to enhanced media players, and, finally, to higher learning effects that let users improve their learning from video

Blickpunktabhängige Computergraphik

Contemporary digital displays feature multi-million pixels at ever-increasing refresh rates. Reality, on the other hand, provides us with a view of the world that is continuous in space and time. The discrepancy between viewing the physical world and its sampled depiction on digital displays gives rise to perceptual quality degradations. By measuring or estimating where we look, gaze-contingent algorithms aim at exploiting the way we visually perceive to remedy visible artifacts. This dissertation presents a variety of novel gaze-contingent algorithms and respective perceptual studies. Chapter 4 and 5 present methods to boost perceived visual quality of conventional video footage when viewed on commodity monitors or projectors. In Chapter 6 a novel head-mounted display with real-time gaze tracking is described. The device enables a large variety of applications in the context of Virtual Reality and Augmented Reality. Using the gaze-tracking VR headset, a novel gaze-contingent render method is described in Chapter 7. The gaze-aware approach greatly reduces computational efforts for shading virtual worlds. The described methods and studies show that gaze-contingent algorithms are able to improve the quality of displayed images and videos or reduce the computational effort for image generation, while display quality perceived by the user does not change.Moderne digitale Bildschirme ermöglichen immer höhere Auflösungen bei ebenfalls steigenden Bildwiederholraten. Die Realität hingegen ist in Raum und Zeit kontinuierlich. Diese Grundverschiedenheit führt beim Betrachter zu perzeptuellen Unterschieden. Die Verfolgung der Aug-Blickrichtung ermöglicht blickpunktabhängige Darstellungsmethoden, die sichtbare Artefakte verhindern können. Diese Dissertation trägt zu vier Bereichen blickpunktabhängiger und wahrnehmungstreuer Darstellungsmethoden bei. Die Verfahren in Kapitel 4 und 5 haben zum Ziel, die wahrgenommene visuelle Qualität von Videos für den Betrachter zu erhöhen, wobei die Videos auf gewöhnlicher Ausgabehardware wie z.B. einem Fernseher oder Projektor dargestellt werden. Kapitel 6 beschreibt die Entwicklung eines neuartigen Head-mounted Displays mit Unterstützung zur Erfassung der Blickrichtung in Echtzeit. Die Kombination der Funktionen ermöglicht eine Reihe interessanter Anwendungen in Bezug auf Virtuelle Realität (VR) und Erweiterte Realität (AR). Das vierte und abschließende Verfahren in Kapitel 7 dieser Dissertation beschreibt einen neuen Algorithmus, der das entwickelte Eye-Tracking Head-mounted Display zum blickpunktabhängigen Rendern nutzt. Die Qualität des Shadings wird hierbei auf Basis eines Wahrnehmungsmodells für jeden Bildpixel in Echtzeit analysiert und angepasst. Das Verfahren hat das Potenzial den Berechnungsaufwand für das Shading einer virtuellen Szene auf ein Bruchteil zu reduzieren. Die in dieser Dissertation beschriebenen Verfahren und Untersuchungen zeigen, dass blickpunktabhängige Algorithmen die Darstellungsqualität von Bildern und Videos wirksam verbessern können, beziehungsweise sich bei gleichbleibender Bildqualität der Berechnungsaufwand des bildgebenden Verfahrens erheblich verringern lässt