Human Self-motion Perception During Vertical Linear Oscillation and Virtual Environment Exposure

Human Self-motion Perception During Vertical Linear Oscillation and Virtual Environment Exposure PDF Author: William Geoffrey Wright
Publisher:
ISBN:
Category : Cognitive neuroscience
Languages : en
Pages : 114

Get Book Here

Book Description

Human Self-motion Perception During Vertical Linear Oscillation and Virtual Environment Exposure

Human Self-motion Perception During Vertical Linear Oscillation and Virtual Environment Exposure PDF Author: William Geoffrey Wright
Publisher:
ISBN:
Category : Cognitive neuroscience
Languages : en
Pages : 114

Get Book Here

Book Description


Human Walking in Virtual Environments

Human Walking in Virtual Environments PDF Author: Frank Steinicke
Publisher: Springer Science & Business Media
ISBN: 1441984321
Category : Technology & Engineering
Languages : en
Pages : 405

Get Book Here

Book Description
This book presents a survey of past and recent developments on human walking in virtual environments with an emphasis on human self-motion perception, the multisensory nature of experiences of walking, conceptual design approaches, current technologies, and applications. The use of Virtual Reality and movement simulation systems is becoming increasingly popular and more accessible to a wide variety of research fields and applications. While, in the past, simulation technologies have focused on developing realistic, interactive visual environments, it is becoming increasingly obvious that our everyday interactions are highly multisensory. Therefore, investigators are beginning to understand the critical importance of developing and validating locomotor interfaces that can allow for realistic, natural behaviours. The book aims to present an overview of what is currently understood about human perception and performance when moving in virtual environments and to situate it relative to the broader scientific and engineering literature on human locomotion and locomotion interfaces. The contents include scientific background and recent empirical findings related to biomechanics, self-motion perception, and physical interactions. The book also discusses conceptual approaches to multimodal sensing, display systems, and interaction for walking in real and virtual environments. Finally, it will present current and emerging applications in areas such as gait and posture rehabilitation, gaming, sports, and architectural design.

Pilot Studies on Object Motion Perception During Linear Self-Motion After Long Duration Centrifugation of Human Subjects

Pilot Studies on Object Motion Perception During Linear Self-Motion After Long Duration Centrifugation of Human Subjects PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 34

Get Book Here

Book Description
Four experiments are reported. They were carried out with the purpose of investigating whether we could use and optimize a particular experimental paradigm to investigate the effects of long duration centrifugation of human subjects. The method involved the psychophysical measurement of visual thresholds for perceiving object motion during self-motion on a linear track sled (acquired by the TNO Institute for Perception from the European Space Agency). Since the experiments were of a preliminary nature-we cannot (yet) draw definite conclusions as to their theoretical interpretation. Nevertheless it can be concluded that we have indeed developed an optimal method. In addition, we have arrived at two hypotheses, which can be tested in further research. According to the first hypothesis, long duration centrifugation affects the way in which visual information interacts with otolith reactivity. According to the second hypothesis, subjects who rely largely on visual information for a correct percept of egomotion are more susceptible to centrifuge induced sickness than others.

A Cybernetic Approach to Self-Motion Perception

A Cybernetic Approach to Self-Motion Perception PDF Author: Florian Soyka
Publisher:
ISBN: 9783832533359
Category :
Languages : en
Pages : 0

Get Book Here

Book Description
Self-motion describes the motion of our body through the environment and is an essential part of our everyday life. The aim of this thesis is to improve our understanding of how humans perceive self-motion, mainly focusing on the role of the vestibular system. Following a cybernetic approach, this is achieved by systematically gathering psychophysical data and then describing it based on mathematical models of the vestibular sensors. Three studies were performed investigating perceptual thresholds for translational and rotational motions and reaction times to self-motion stimuli. Based on these studies, a model is introduced which is able to describe thresholds for arbitrary motion stimuli varying in duration and acceleration profile shape. This constitutes a significant addition to the existing literature since previous models only took into account the effect of stimulus duration, neglecting the actual time course of the acceleration profile. In the first and second study model parameters were identified based on measurements of direction discrimination thresholds for translational and rotational motions. These models were used in the third study to successfully predict differences in reaction times between varying motion stimuli proving the validity of the modeling approach. This work can allow for optimizing motion simulator control algorithms based on self-motion perception models and developing perception based diagnostics for patients suffering from vestibular disorders.

The Effects of Gravity on Self-Motion Perception

The Effects of Gravity on Self-Motion Perception PDF Author: Pearl Shaina Guterman
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

Get Book Here

Book Description
Gravity is the most pervasive force that we encounter. For instance, we observe a variety of objects being accelerated toward the Earth by gravity, but we also experience these forces when we are simply stationaryas gravity is a constant accelerationor when we are ourselves in motion, such as when we are locomoting on foot, driving a vehicle, jumping or skiing. It follows that our ability to successfully navigate our environment must somehow take into account the effects of gravity on our body's motion-detecting sensesa dynamic relationship which changes with self-motion and self-orientation. The goal of this dissertation was to investigate how body orientation relative to gravity influences visual-vestibular interactions in visually-induced perception of self-motion (i.e., vection). Specifically, I examined this relationship by placing observers in varied postures and presenting visual displays simulating forward/backward self-motion with vertical/horizontal viewpoint oscillation, that mimics components produced by head-movements in real self-motion. I found that tilting observers reduced vection and the two viewpoint oscillations similarly enhanced vection, suggesting that current postural and oscillation-based vection findings are best explained by ecology. I also examined the influence of scene structure and alignment of the body and visual motion relative to gravity on vection. Observers in different postures viewed simulated translational self-motion displays consisting of either a single rigid structure or dots. The experimental data showed that vection depended on both posture and the perceived interpretation of the visual scene, indicating that self-motion perception is modulated by high-order cognitive processes. I also found that observers reported illusory tilt of the stimulus when they were not upright. I investigated these observer reports of a posture-dependent perceived stimulus tilt by presenting upright and tilted observers with static and motion stimuli that were tilted from the graviational vertical. Postural-dependent tilt effects were found for both these stimuli and were greater for motion experienced as self-motion than external motion. Taken together, the results of this dissertation demonstrate that our perception of self-motion is influenced by gravity, and by prior experiences and internal mental representations of our visual world.

Adaptation to a Linear Vection Stimulus in a Virtual Reality Environment

Adaptation to a Linear Vection Stimulus in a Virtual Reality Environment PDF Author: Christine Anne Tovee
Publisher:
ISBN:
Category :
Languages : en
Pages : 111

Get Book Here

Book Description


Perception of True Linear Self-motion Using Vestibular Stimulation in Humans

Perception of True Linear Self-motion Using Vestibular Stimulation in Humans PDF Author: Hugh Nolan
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description


Motion Perception with Conflicting Or Congruent Visual and Vestibular Cues

Motion Perception with Conflicting Or Congruent Visual and Vestibular Cues PDF Author: Andrew Alan Rader
Publisher:
ISBN:
Category :
Languages : en
Pages : 145

Get Book Here

Book Description
Introduction: We are required on a daily basis to estimate our position and motion in space by centrally combining noisy, incomplete, and potentially conflicting or ambiguous, information from both sensory sources (e.g. vestibular organs, visual, proprioceptive), and non-sensory sources (e.g. efferent copy, cognition)). This "spatial orientation" is normally subconscious, and information from multiple sense organs is automatically fused into perception. As late as the early nineteenth century, very little was known about the underlying mechanisms, and our understanding of some critical factors such as such as how the brain resolves the tilt-translation ambiguity is only now beginning to be understood. The otolith organs function like a three-axis linear accelerometer, responding to the vector difference between gravity and linear acceleration (GIF= g - a). How does the brain separate gravity from linear acceleration? How does the brain combine cues from disparate sensors to derive an overall perception of motion? What happens if these sensors provide conflicting information? Humans routinely perform balance tasks on a daily basis, sometimes in the absence of visual cues. The inherent complexity of the tasks is evidenced by the wide range of balance pathologies and locomotive difficulties experienced by people with vestibular disorders. Maintaining balance involves stabilizing the body's inverted pendulum dynamics where the center of rotation (at the ankles) is below the center of mass and the vestibular sensors are above the center of rotation (for example, swaying above the ground level or balancing during standing or walking). This type of swing motion is also encountered in most fixed-wing aircraft and flight simulators, where the pilot is above the center of roll. Swing motions where the center of mass and sensors are below the center of rotation are encountered on a child's swing, and in some high-wing aircraft and helicopters. Spatial orientation tasks requiring central integration of sensory information are ubiquitous in aerospace. Spatial disorientation, often triggered by unusual visual or flight conditions, is attributed to around 10% of aviation accidents, and many of these are fatal. Simulator training is a key factor in establishing the supremacy of instrument-driven flight information over vestibular and other human sensory cues in the absence of reliable visual information. It therefore becomes important to ensure that simulators re-create motion perceptions as accurately as possible. What cues can safely be ignored or replaced with analogous cues? How realistic and consistent must a visual scene be to maintain perceptual fidelity? Spatial orientation is also a critical human factor in spaceflight. Orientation and navigation are impaired by the lack of confirming gravitation cues in microgravity, as sensory cues are misinterpreted and generate the incorrect motion perceptions. These persist at least until the vestibular or central nervous system pathways adapt to the altered gravity environment, however human navigation never fully adapts to the three dimensional frame. There is a wealth of data describing the difficulties with balance, gait, gaze control, and spatial orientation on return to Earth. Post-flight ataxia (a neurological sign of gross incoordination of motor movements) is a serious concern for all returning space travelers for at least ten days. This would be an even more serious concern for newly arrived astronauts conducting operations extraterrestrial environments after a long space flight. What motion profiles in a lunar landing simulator on Earth will best prepare astronauts for the real task in an altered gravity environment? Far from being a problem restricted to a human operator, the aerospace systems themselves face the same challenge of integrating sensory information for navigation. Modeling how the brain performs multi-sensory integration has analogies to how aircraft and spacecraft perform this task, and in fact modelers have employed similar techniques. Thus, developments in modeling multi-sensory integration improve our understanding of both the operator and the vehicle. Specifically, this research is concerned with how human motion perception is affected during swing motion when vestibular information is incomplete or ambiguous, or when conflicting visual information is provided.

Augmentation of Brain Function: Facts, Fiction and Controversy

Augmentation of Brain Function: Facts, Fiction and Controversy PDF Author: Mikhail Lebedev
Publisher: Frontiers Media SA
ISBN: 2889456145
Category : Neurosciences. Biological psychiatry. Neuropsychiatry
Languages : en
Pages : 666

Get Book Here

Book Description
Volume I, entitled “Augmentation of Brain Functions: Brain-Machine Interfaces”, is a collection of articles on neuroprosthetic technologies that utilize brain-machine interfaces (BMIs). BMIs strive to augment the brain by linking neural activity, recorded invasively or noninvasively, to external devices, such as arm prostheses, exoskeletons that enable bipedal walking, means of communication and technologies that augment attention. In addition to many practical applications, BMIs provide useful research tools for basic science. Several articles cover challenges and controversies in this rapidly developing field, such as ways to improve information transfer rate. BMIs can be applied to the awake state of the brain and to the sleep state, as well. BMIs can augment action planning and decision making. Importantly, BMI operations evoke brain plasticity, which can have long-lasting effects. Advanced neural decoding algorithms that utilize optimal feedback controllers are key to the BMI performance. BMI approach can be combined with the other augmentation methods; such systems are called hybrid BMIs. Overall, it appears that BMI will lead to many powerful and practical brain-augmenting technologies in the future.

Dissertation Abstracts International

Dissertation Abstracts International PDF Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 756

Get Book Here

Book Description