Texte intégral / Full text (pdf, 20 MiB) - Infoscience - EPFL

1.3. Contributions
in areas of daily life. The diagnosis can be of a specific disorder (when only some specific
situations are feared) or a generalized disorder. The main characteristic of social phobia is
the underlying fear of being negatively evaluated or judged by others [American Psychiatric
Association, 1994]. Patients suffering from social phobia fear of being embarrassed or humiliated.
Though these fears may be recognized by the patient as excessive or unreasonable,
it can be extremely difficult to overcome them. Phobic patients completely or partially avoid
certain situations by minimizing visual contact, verbal communication or physical presence.
They rely on avoidance behaviors to calm down their fears. Social phobia is an anxiety disorder
which concerns up to 13.3% of the population [Heimberg, 1995] and has an important
social impact on the way people live their lives. The aim of the tools and applications we
have developed is to assist therapists in the treatment of social phobia. Exposure to virtual
scenarios can replace in-vivo exposure in many contexts and can be much easier to use.
The second part of this thesis is focused on agoraphobia with crowds. Agoraphobia is
an abnormal and persistent fear of public places or open areas. It is an anxiety provoked by
being in places or situations from which escape is difficult. It can also be a fear of being
in a place where it is impossible to obtain help in case of panic attack. Different forms of
this anxiety translate in a fear of open spaces, traveling, or crowds [American Psychiatric
Association, 1994]. It is this last specific type of agoraphobia that we work on in this thesis.
Agoraphobia is an anxiety disorder which occurs twice as much in women than in men and
concerns 2% to 4% of the population. Here as well, the aim of the application we have
developed is to provide therapists with a tool which can be used in the treatment of social
phobia. The benefit which can be found in using VRET for the treatment of agoraphobia
with crowds is even more conspicuous since it is a situation very difficult to regulate in vivo.
Our application allows for gradual exposure to virtual crowds in a very immersive context.
Finally, in the last part of this thesis, we describe the various experiments we have conducted
in order to validate our various tools and applications in the context of social phobia
and agoraphobia with crowds.
1.3 Contributions
In the first part of this thesis, we desribe the various tools and applications we have developed
to be used in VRET to treat social phobia and more specifically, fear of public speaking.
Previous studies on social phobia together with our first experiments in the domain, have
raised our interest towards eye contact analysis and simulation. Eye contact is a crucial part
of our interactions with others, and it is a known to be often avoided by people suffering
from social phobia. In this context, we first describe our methods to create various VRET
scenarios and to endow our virtual characters with various behaviors. We then describe a
behavioral model we have developed for characters to seem aware of the presence of the
user or the phobic patient and to interact with him/her.
In the second part of this thesis, we focus on VRET of agoraphobia with crowds. In this
context, we describe a gaze attention model we have developed for virtual crowd characters.
In this model, we automatically detect where and when each character should look and adapt
their motion in order for them to perform the gaze motions in a smooth and natural way.
13