Virtual reality exposure therapy for social phobia

This thesis presents researches and experiments performed in collaboration with a psychiatrist in order to validate and improve the use of virtual reality in social phobia psychotherapy. Cognitive and behavioral therapies are strongly based on the exposure to anxiety provoking stimuli. Virtual reality seems to be appropriate for such exposures as it allows for on-demand reproduction of reality. The idea has been validated for the treatment of various phobias but is more delicate in the case of social phobia; whereas the sense of presence provoked by the immersion in a virtual environment supports the emergence of fears linked to a location, we had to verify that we can reproduce social phobia related anxiety-provoking stimuli by simulating virtual humans. Therefore, and in order to provide therapists with an efficient virtual reality system dedicated to the exposure to social situations, we have developed software solutions supporting different immersion setups and enabling realistic simulations of inhabited virtual environments. We have experimented with public speaking scenarios within a preliminary study, three clinical case studies and a validation study on 200 subjects. We have been able to confirm that our virtual reality platform fulfilled therapeutic exposure requirements for social phobia. Moreover, we have been able to show that virtual reality exposure has additional advantages such as the possibility to improve clinical assessment with embedded monitoring tools. Our experiments with physiological measurements and eye tracking technology during immersion leaded to the validation of systems for objective and reliable assessment of patients' safety behaviors. The observation of such phobic reactions has confirmed the simulation impact and may provide therapists with enhanced pathological progression monitoring. During our experiments, we have also been able to observe that subjects' reactions during immersion were so much influenced by their sensitivity to fearful stimuli that their cognitive reactions were 'overloaded' by the arousal of anxiety and emotions. This has allowed us to consider that the sense of presence was more importantly related to the subjective impact of the content than to the technological process

Customising games for non-formal rehabilitation

The field of rehabilitation has increasingly adopted commercially available games using perceptual interfaces as a means for physically training patients. The adaptability of such systems to match each person’s need and rehabilitation goal remains problematic. This paper presents a rapid prototyping approach for customising gaming technology using various affordable commercial devices and open source software. We first demonstrate how a freely available game is adapted for training disabled people through different sensors and control modes. We then show how an open online virtual world such as Second Life® offers sufficient conditions for quickly building custom content for testing with interactive devices. When presented with these prototyping possibilities, people from the target groups (healthcare professionals, patients, people with disabilities, older people, families) related such systems to their needs and further elaborated on the use of such systems. Our research indicates how availability of simple prototyping platforms expands upon the possibilities for developers and practitioners

Turning body and self inside out: visualized heartbeats alter bodily self-consciousness and tactile perception

Prominent theories highlight the importance of bodily perception for self-consciousness, but it is currently not known whether bodily perception is based on interoceptive or exteroceptive signals or on integrated signals from these anatomically distinct systems. In the research reported here, we combined both types of signals by surreptitiously providing participants with visual exteroceptive information about their heartbeat: A real-time video image of a periodically illuminated silhouette outlined participants' (projected, "virtual") bodies and flashed in synchrony with their heartbeats. We investigated whether these "cardio-visual" signals could modulate bodily self-consciousness and tactile perception. We report two main findings. First, synchronous cardio-visual signals increased self-identification with and self-location toward the virtual body, and second, they altered the perception of tactile stimuli applied to participants' backs so that touch was mislocalized toward the virtual body. We argue that the integration of signals from the inside and the outside of the human body is a fundamental neurobiological process underlying self-consciousness

Neural Mechanisms of Bodily Self-Consciousness and the Experience of Presence in Virtual Reality

Recent neuroscience research emphasizes the embodied origins of the experience of the self. This chapter shows that further advances in the understanding of the phenomenon of VR-induced presence might be achieved in connection with advances in the understanding of the brain mechanisms of bodily self-consciousness. By reviewing the neural mechanisms that make the virtual reality experience possible and the neurocognitive models of bodily self-consciousness, we highlight how the development of applied human computer confluence technologies and the fundamental scientific investigation of bodily self-consciousness benefit from each other in a symbiotic manner

Characterizing Embodied Interaction in First and Third Person Perspective Viewpoints

Third Person Perspective (3PP) viewpoints have the potential to expand how one perceives and acts in a virtual environment. They offer increased awareness of the posture and of the surrounding of the virtual body as compared to First Person Perspective (1PP). But from another standpoint, 3PP can be considered as less effective for inducing a strong sense of embodiment into a virtual body. Following an experimental paradigm based on full body motion capture and immersive interaction, this study investigates the effect of perspective and of visuomotor synchrony on the sense of embodiment. It provides evidence supporting a high sense of embodiment in both 1PP and 3PP during engaging motor tasks, as well as guidelines for choosing the optimal perspective depending on location of targets

Posing for awareness: Proprioception modulates access to visual consciousness in a continuous flash suppression task

The rules governing the selection of which sensory information reaches consciousness are yet unknown. Of our senses, vision is often considered to be the dominant sense, and the effects of bodily senses, such as proprioception, on visual consciousness are frequently overlooked. Here, we demonstrate that the position of the body influences visual consciousness. We induced perceptual suppression by using continuous flash suppression. Participants had to judge the orientation a target stimulus embedded in a task-irrelevant picture of a hand. The picture of the hand could either be congruent or incongruent with the participants' actual hand position. When the viewed and the real hand positions were congruent, perceptual suppression was broken more rapidly than during incongruent trials. Our findings provide the first evidence of a proprioceptive bias in visual consciousness, suggesting that proprioception not only influences the perception of one's own body and self-consciousness, but also visual consciousness