Dynamic Difficulty Adjustment Through Real-Time Physiological Feedback for a More Adapted Virtual Reality Exposure Therapy.

Like many researchers, we think that the use of dynamic difficulty adjustment (DDA) to offer an appropriate balance between the skills of the player and the difficulty of the gameplay is an appropriate avenue to maintain the flow of a user. We analyze this approach in a virtual reality serious game dedicated to people suffering from post-traumatic stress disorder (PTSD). Knowing that heart rate is a good indicator of the emotional state of people with PTSD, we collect this variable in real-time to propose a virtual reality dynamic adjusted system based on the emotional state of the subject. The proposed adaptation system can be approached in three modes: the offline mode which consists on therapist selections before launching the game, the manual online mode during which the therapist can adapt the virtual environment while the subject is exposed, and the computational online mode that runs a DDA algorithm to automatically adjust the game.