Sensorimotor experience in virtual environments

The goal of rehabilitation is to reduce impairment and provide functional improvements resulting in quality participation in activities of life, Plasticity and motor learning principles provide inspiration for therapeutic interventions including movement repetition in a virtual reality environment, The objective of this research work was to investigate functional specific measurements (kinematic, behavioral) and neural correlates of motor experience of hand gesture activities in virtual environments stimulating sensory experience (VE) using a hand agent model. The fMRI compatible Virtual Environment Sign Language Instruction (VESLI) System was designed and developed to provide a number of rehabilitation and measurement features, to identify optimal learning conditions for individuals and to track changes in performance over time. Therapies and measurements incorporated into VESLI target and track specific impairments underlying dysfunction. The goal of improved measurement is to develop targeted interventions embedded in higher level tasks and to accurately track specific gains to understand the responses to treatment, and the impact the response may have upon higher level function such as participation in life. To further clarify the biological model of motor experiences and to understand the added value and role of virtual sensory stimulation and feedback which includes seeing one\u27s own hand movement, functional brain mapping was conducted with simultaneous kinematic analysis in healthy controls and in stroke subjects. It is believed that through the understanding of these neural activations, rehabilitation strategies advantaging the principles of plasticity and motor learning will become possible. The present research assessed successful practice conditions promoting gesture learning behavior in the individual. For the first time, functional imaging experiments mapped neural correlates of human interactions with complex virtual reality hands avatars moving synchronously with the subject\u27s own hands, Findings indicate that healthy control subjects learned intransitive gestures in virtual environments using the first and third person avatars, picture and text definitions, and while viewing visual feedback of their own hands, virtual hands avatars, and in the control condition, hidden hands. Moreover, exercise in a virtual environment with a first person avatar of hands recruited insular cortex activation over time, which might indicate that this activation has been associated with a sense of agency. Sensory augmentation in virtual environments modulated activations of important brain regions associated with action observation and action execution. Quality of the visual feedback was modulated and brain areas were identified where the amount of brain activation was positively or negatively correlated with the visual feedback, When subjects moved the right hand and saw unexpected response, the left virtual avatar hand moved, neural activation increased in the motor cortex ipsilateral to the moving hand This visual modulation might provide a helpful rehabilitation therapy for people with paralysis of the limb through visual augmentation of skills. A model was developed to study the effects of sensorimotor experience in virtual environments, and findings of the effect of sensorimotor experience in virtual environments upon brain activity and related behavioral measures. The research model represents a significant contribution to neuroscience research, and translational engineering practice, A model of neural activations correlated with kinematics and behavior can profoundly influence the delivery of rehabilitative services in the coming years by giving clinicians a framework for engaging patients in a sensorimotor environment that can optimally facilitate neural reorganization

Development of a model based on virtual reality for the evaluation of behavioral compliance with warnings and wayfinding contexts

Virtual Reality (VR) when framed in adequate methodologies, has an ample field of application for Ergonomics and for Design, since it allows to analyze and understand how people interaction with simulated situations in Virtual Environments (VEs). As such, it is of extreme importance for research and the practice of Ergonomics, to understand how it is possible to optimize, create, implement and evaluate solutions based in VEs in different contexts, including dangerous one, in particular those that can place in risk the physical integrity of people. These VEs can be used to study the Human behavior in critical situations, which is important when projecting products and systems that involve dangers to the users that would be difficult to study otherwise. In this context, this project has as its general objective the study of the factors that influence the development of VEs for VR and in the implementation of solutions (with a focus on the software and hardware) that better can correspond to the development of this type of studies, namely in studies of behavioral compliance with warnings and in studies of wayfinding. The methodological proposal described in this document focuses in a User-Centered Design (UCD) perspective, which involved the participation of the users, in the different phases of development of the project. As a result, it was developed and evaluated software and hardware solutions for the understanding and evaluation of the factors associated to the study of Human behavior, namely in behavioral compliance with warnings and in wayfinding contexts. It was also studied the best solutions for interaction and navigation in VEs, that correspond to high levels of presence, which is a fundamental aspect in behavioral compliance with warnings and wayfinding studies that use VR as a support tool. With this purpose, two navigational interfaces were developed (i.e., Balance Board and Walk-in-Place), also in a UCD perspective, to guarantee a constant cycle of tests and improvement of the implementations among the users. A comparative study was made between these two navigational interfaces and another that is commonly used in studies with VR (i.e., a Joystick). This comparative study was conducted in a context of evaluation of behavioral compliance with warnings and performance variables were analyzed, as well as the levels of presence in the different navigational interfaces. There were no statistically significant differences in the levels of presence or in the behavioral compliance between the three navigational interfaces. However, statistically significant differences were found in several performance variables (e.g., average speed, total distance). Future directions for the research are also discussed.A Realidade Virtual (RV) quando enquadrada em metodologias adequadas, tem um campo de aplicação alargado para a Ergonomia e o Design, visto permitir analisar e compreender como as pessoas interagem com situações simuladas em Ambientes Virtuais (AVs). Desta forma, é de extrema importância para a investigação ou prática da Ergonomia, perceber como se pode optimizar, construir, implementar e avaliar soluções baseadas em AVs em diferentes contextos, incluindo contextos perigosos, particularmente aqueles que podem colocar em risco a integridade física das pessoas. Estes AVs podem ser usados para estudar o comportamento Humano em situações críticas, o que é importante quando se projecta produtos e sistemas que envolvam perigos para os utilizadores que de outra forma seria muito difícil avaliar. Neste contexto, este projecto tem como objectivo geral o estudo dos factores que influenciam o desenvolvimento de ambientes para Realidade Virtual e na implementação de soluções (com um foco maior no software e hardware) que melhor possam corresponder ao desenvolvimento deste tipo de estudos, nomeadamente em estudos de consonância comportamental com avisos de segurança e estudos de wayfinding. A proposta metodológica descrita neste documento foca-se numa perspectiva de Design Centrado no Utilizador (DCU), que envolveu a participação dos utilizadores, nas várias fases de desenvolvimento do projecto. Como resultado, desenvolveu-se e avaliou-se soluções de software e hardware para a compreensão e avaliação dos factores associados ao estudo do comportamento Humano, nomeadamente para a consonância comportamental com avisos de segurança e para situações de wayfinding. Foram também estudadas as melhores soluções para interacção e navegação em AVs, que correspondam a níveis de presença elevados, aspecto fundamental em estudos de consonância comportamental com avisos de segurança e em estudos de wayfinding que usam RV. Com este intuito, foram desenvolvidas duas interfaces de navegação para Realidade Virtual (i.e., Balance Board e Walk-in-Place), também numa perspectiva de DCU, para garantir um constante ciclo de testes e aperfeiçoamento das implementações junto dos utilizadores. Foi realizado um estudo comparativo entre estas duas interfaces de navegação e uma outra que é utilizada mais frequentemente em estudos com RV (i.e., um Joystick). Este estudo comparativo realizou-se num contexto de avaliação da consonância comportamental com avisos de segurança e foram analisadas variáveis de desempenho, assim como os níveis de presença das diferentes interfaces de navegação. Não se observaram diferenças estatisticamente significativas em relação aos níveis de presença nem em relação à consonância comportamental entre as três interfaces de navegação. No entanto, foram encontradas diferenças estatisticamente significativas em várias variáveis de desempenho (e.g., velocidade média, distância percorrida). Também são discutidas as possíveis linhas de investigação de continuação ao trabalho