# Immersive Phobia Therapy through Adaptive Virtual Reality and Biofeedback
## 2 Phobia Statistics and Therapy Methods
### Virtual Reality Exposure Therapy Systems Developed in the Academic Context
The scene is enriched with buildings, moving cars, sky, and moving clouds, which increase presence. People suffering from glossophobia are more nervous than their non-phobic peers when speaking in an empty seminar room and in front of a virtual audience with neutral behavior, as suggested by the experiment presented in [25]. On the other hand, a hostile attitude from the audience generates powerful emotions in the speakers, both confident speakers and glossophobic [26]. The DIVE [27] virtual environment has been used for creating two scenarios: one in which the audience is friendly and the other with a hostile audience. After analyzing the data from physiological measurements and speaking performance, it was found that co-presence is associated with the attitude of the avatars from the virtual audience. In the game presented in [28], the player can modify the settings of the audience who can interact with the speaker through laughter, comments, encouragement, or clapping. The virtual reality therapy group comprising eight subjects achieved significant improvements after the 5-week therapy, whereas the performance of the control group remained the same. An increase in anxiety was observed at the beginning of the 10-20 min long session and a considerable decrease was noted in the middle of exposure. Some 360-degree virtual environments were used in [29], depicting three training scenarios: an empty classroom, a classroom with a small audience, and a classroom with a large audience. The results obtained from an experiment with 35 subjects showed that anxiety levels decreased, especially for subjects who recorded high baseline anxiety levels. Young software engineers were required to give a speech on one of several controversial subjects in front of a virtual audience in another study [30]. The psychotherapist had the possibility to orchestrate the scenario and manipulate the audience's reactions. The authors reached the conclusion that consistent therapy is effective in reducing anxiety levels. The AwareMe system [31] incorporates a module that monitors voice factors: pitch, filler words, and number of spoken words. A wristband offers visual and haptic feedback during presentations. In a large experiment, the data from 66 subjects were recorded (self-reported anxiety, heart rate, heart rate variability, and saliva cortisol secretions) in three different settings: a real audience in a real-world lecture hall, a full lecture hall in VR, and an empty lecture hall in VR with disturbing sounds. The results showed similar stress patterns under both real-world and VR conditions, and no significant differences between male and female participants. An evaluation of the PubVR system as a therapy tool for fear of public speaking [32] focused on patients' perception and experience concerning live-controlled avatar interactions compared with standard prerecorded animations. Notably, 24 healthy subjects were divided into two groups: The experimental group received voice and upper-body movement input from the orchestrator using a motion-tracking camera, while the control group received predefined animations and prerecorded statements. The results from the qualitative analysis indicated that the participants from the experimental group felt more comfortable when they received a spontaneous answer and when they could initiate a dialogue with follow-up questions during the therapy session. Other observations showedthat subjects tend to pause their presentation when there is no direct interaction, causing a break in presence.