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Chapter 6. Experimental Validations - Social Phobia
6.3.2 Experimental Protocol
All subjects first started with a pre-treatment, individual, eye-tracking session. We first explained
them how the system worked and that we were going to analyze the way they used
their eyes in a public speaking situation. The phobic subjects were neither told which behaviors
were typical of social phobia nor that their results would be compared to those of
subjects from a control group. Similarly, the control group subjects were not aware that their
results would be compared to those of phobic subjects. Once the session was over, we informed
them all that they would be coming back for a second session, twelve weeks later.
This corresponded to the end of the therapy for the phobic subjects. The five people from
the social phobic group then underwent a 10 week group therapy following the Boston group
protocol. Three out of the five subjects then came back for the second eye-tracking session.
One of the two others started an individual therapy after two sessions with the group and
the other stopped the therapy after seven sessions. We therefore decided to exclude them
from the second eye-tracking session. Likewise, we only included the second set of results
of the three first subjects from the control group into the study in order for their number to
correspond to the phobic subjects’.
6.3.2.1 Pre-treatment Eye-tracking
We first equipped the subjects with the eye-tracker and seated them in front of the large
back-projection screen. They then went through the calibration process and a phase of accommodation
to the equipment. This accommodation phase was a kind of game, during
which we asked them to write their name on the screen with their tracked eye. This was done
also in order to make them feel more at ease and relaxed. We then asked them to do a public
speaking exercise in front of two different VR scenes, during which their eye movements
were recorded. The conditions and discussion topics were kept the same for each subject.
The first of these VEs, depicted on the middle left of Figure 3.1, was a single person in a bar.
The second, shown on the bottom left of Figure 3.1, reproduced an auditorium environment
with approximately 20 characters. As for the previous experiment, in order to avoid breaks in
presence and to enhance interaction, the discussions were not lead by the therapist. Instead,
they were lead by the main character in each of the two scenes. We did this by triggering
pre-recorded sentences and thus simulating the virtual character’s speech. For each of these
scenes, we asked the subjects to talk for a couple of minutes on a given theme. We tracked
the subjects’ eyes during these exercises in order to analyze their visual behaviors. In this
first phase, we analyzed the collected data in order to see if there was a noticeable difference
in behavior between the phobic subjects and the subjects from the control group.
6.3.2.2 Group Therapy
The phobic subjects then went through ten sessions of weekly therapy. These sessions were
based on the Boston group protocol [Stern et al., 1999]. The subjects were asked to do presentations
on given themes in front of the other members of the group. These sessions were
filmed and then analyzed by each patient with the psychiatrist. Each presentation comprised
a subject more personal and difficult to talk about than the previous. As an example, for the
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