COGNITIVE STATE CLASSIFICATION IN VR: THE RELATION BETWEEN SUBJECTIVE QUALITY OF EXPERIENCE, MOVEMENT AND VIDEO QUALITY IN VIRTUAL REALITY

We conducted a within-subject study in which every participant used the HTC Vive Pro Eye head-mounted display (HMD) to view four versions of a five-minute-long animated movie. The movie INVASION! Each participant viewed the following versions of INVASION!: (1) high-quality (Q1) - 2469 × 2743 pixels; (2) medium quality 1 (Q2) - 1808 × 2009 pixels; (3) medium quality 2 (Q3) - 1169 ×1298 pixels; (4) low quality (Q4) - 512 × 549 pixels. To establish the quality versions, we first determined the highest resolution version to play the movie without video jitter (Q1). Next, we linearly degraded the resolution to create the three lower video-quality versions (Q2, Q3, Q4). The order of viewing was counterbalanced using balanced Latin squares. This created four viewing orders in which each video quality preceded and followed every other video quality an equal number of times. During the session, participants were fitted in an EEG cap with 64 electrodes. We used electrode gel to improve the connectivity of the electrodes and reach impedance values below 20. Then, The ANT NEURO 224 amplifier and recording Microsoft Surface Pro tablet were put in an ANT NEURO backpack and placed on the back of the participant. Afterward, the researcher placed the HMD on top of the EEG cap while making sure that the HMD was not disturbing the EEG signal. Once the full setup was completed, the participant viewed the first version of INVASION! Participants were instructed to explore the VE by walking and looking around. After the end of the video, the researcher took off the HMD and the participant completed a five-minute-long questionnaire.