Agoraphobia Studies

The idea is to recreate a believable artificial environment that stimulates physical responses as a real one, but that can be individually controlled by the suffer to experience only the features that can be handled by the patient. As the techniques to cope with the anxiety are learned trough a number of virtual sessions, the richness of the environment is increased to transform the virtual into a real world bringing the patient to be able to cope with the anxieties in the everyday experience.

Phobia treatment via virtual reality exposure therapy (VRET) is one of the emerging and most effective applications of virtual environments. Patients are exposed to anxiety causing stimuli in a fully controllable environment. Furthermore using the responses of people suffering of a conditions such as phobia, who demonstrate clear and measurable behavioural alterations, allows to investigate the effectiveness of virtual environments in triggering the sense of presence, the feeling that one might be actually experiencing a real place rather than a synthetic representation.

Person in the UCL ReaCTor

Previous work at UCL focussed on fear of public speaking. We have worked closely with colleagues in the Institute of Psychiatry and Department of Psychology, collaborating on a number of experimental and pre-clinical trials on the utility of immersive virtual environments in treating these conditions. Our studies in computer science have not focussed on treatment itself, but have shown that virtual environments have appropriate effects on users and thus can be used in therapeutic situations.

Interacting with Another User in the ReaCTor

Aside from its intrinsic interest for our collaborators in psychiatry, our agoraphobia work is a mechanism for studying what makes virtual environments effective. By effective, we mean both generating a reported subjective sense of “being there”, but also generating appropriate objective responses. Our focus in the recent round of experiments has been in establishing physiological measures such as BVP, GSR, etc. that can be used to confirm that a person is suffering from stress. By using stress as a surrogate for presence, we can investigate appropriate responses. We are currently attempting to build models that integrate this with our previous “breaks in presence” studies.

Realism and Presence in Virtual Urban Environments

In our first study we have been trying to understand what characteristics the urban virtual environment and the avatars populating them should exhibit in order to maintain and achieve the response of presence responses from the humans navigating them. A group of 60 subjects have experienced one of six “case studies” – each is a virtual representation of a public space. These representations range from compact spaces, to crowded outdoor spaces. This study is used to generate hypotheses and what characteristics of a model generate a sense of presence of the model. This follows up previous work in Equator about mismatch between representation and behaviour. We have used subjective responses using a variant of Slater-Usoh-Steed, physiological measures and the breaks in presence method.

Case Study Worlds 1

Case Study Worlds 2

Case Study Worlds 3

Agoraphobic and Non Perceptions of Virtual Urban Environments

In this study we were interested in comparing the reaction to urban virtual environments between people suffering from agoraphobia in comparison with people without this condition. This is a smaller scale exploratory trial where each participant experiences all six “case study” worlds in order that we can investigate what aspects generate high levels of stress. Would the agoraphobia sufferers feel uncomfortable in the presence of virtual people as they do with real people? What makes virtual people and buildings effective? Comparing responses to virtual urban environments of phobic and people without this condition is necessary to understand ordinary and exalted perception of virtual urban environments.

Perceptions of Realism in a Virtual Urban Environment

One insight our work has provided is that pictorial realism is not sufficient nor necessary to create a sense of presence. What seems to be important is that the world is consistent and believable, and that the world behaves appropriately In the current experiment have picked up on two aspects of the first two studies that seemed very important, sense of space and avatars, and are looking at interactions between different levels of visual realism and behavioural reaslim. There is a single world that resembles a typical high street. A subsidiary goal is to drive platform work. This means integrating, the PIAVCA written in collaboration with BT Exact, DIVE, eye-tracking and physiological monitoring into a stable system.