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2.1. Virtual Reality Exposure Therapy
Figure 2.4: Left: An audience consisting of picture of eyes [Herbelin et al., 2002]. Right:
Disinterested characters in bar environment [James et al., 2003].
the virtual audience in an HMD. From their results, the authors concluded that VRET had a
high potential in replacing in-vivo situations.
Anderson et al. proposed a VR scenario consisting in a classroom with a virtual desk on
which text was written [Anderson et al., 2003]. This text could be used as notes for a public
speaking exercise. They used video inlay to insert an audience of 5 people in the virtual
classroom. The authors then tested their application on two social phobic patients exposed
to the scenario through an HMD. Their results proved this treatment to be efficient.
James et al. proposed a two-fold scenario to evaluate the potential of generating social
anxiety in VEs [James et al., 2003]. The first part consisted in an underground train in which
the characters expressed neutral behaviors. The second, depicted on the right of Figure 2.4
was a bar in which the characters seemed very disinterested. They simulated those behaviors
with gaze and pre-recorded sentences as in [Slater et al., 1999]. They then asked 10 subjects
to evaluate different scenarios. Their results showed that a socially demanding VE is more
anxiety provoking for a phobic subject than a non-socially demanding one.
Within the VEPSY Updated project [vepsy, 2009], Klinger et al. proposed a system to
tackle various factors of social phobia, namely, performance, scrutiny, intimacy and assertion
[Klinger et al., 2002; Roy et al., 2003]. To this end they created four different environments
depicting a meeting room, outside a coffee shop, an appartment, and a walkthrough
going from an appartment to a shop, including a lift. These were done in 3dsMax [Autodesk,
2009] and integrated into an interactive environment using Virtools Dev 2.0 [Dassault
Systèmes, 2009], providing the rendering engine as well as a behavioral engine to define the
various possible interactions between the user and the virtual characters or objects in the environment
(e.g. pull a chair with the mouse). For the characters, they used 3D sprites. They
used simple billboards on which were projected pictures of real people involved in daily situations.
Finally, they used background sound and pre-recorded sentences for the dialogues
with the patient. The authors then tested this in a defined evaluation protocol on 10 phobic
patients. Klinger et al. then further experimented this same protocol on 36 patients diagnosed
with social phobia [Klinger et al., 2005]. The results of both these studies showed that VRET
and traditional CBT both were clinically valid and that the difference in results between the
two was trivial. An example of their system is illustrated on the right of Figure 2.3.
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