Analysis of locomotion techniques in EEG-supported virtual reality environment in terms of objective and subjective measurements

Virtual reality (VR) systems are technological systems where individuals experience a sense of presence in a computer-simulated three-dimensional space by utilizing computer capabilities within the physical environment. The technique that allows users to move in these virtual environments is called VR Locomotion. With the increasing popularity and expanding application areas of VR technology, understanding the effects of different locomotion techniques in virtual environments on user experience is becoming important. This thesis study aimed to analyze locomotion techniques in an EEG-supported virtual reality environment in terms of objective and subjective measurements. The physiological effects on users of ten different VR locomotion techniques (real-time walking, teleportation, shifting, continuous, continuous hand, climbing, hanging climbing, touching, walking, and running) were evaluated objectively using EEG signals, and the subjective workload perception was determined with the NASA-TLX scale. The readily available VREEG dataset was used within the scope of the research. EEG data were preprocessed and time and frequency-based features were extracted. RF, SVM, and kNN machine learning algorithms were used to classify locomotion techniques. According to the NASA-TLX results, locomotion techniques significantly affected physical demand, effort, and frustration levels (p <0.05). Climbing and hanging climbing techniques resulted in the highest workload (p<0.05). In EEG classification, RF and kNN algorithms showed successful performance with high accuracy. Correlation analyses found negative relationships between classification accuracy and mental demand and frustration, and positive relationships between physical demand and effort. This study showed that VR locomotion techniques create different loads on users and that EEG can be used for objective classification of this load. The results emphasize the importance of selecting locomotion techniques to improve user experience.