The Effects of Degrees of Freedom and Field of View on Motion Sickness in a Virtual Reality Context

Abstract

With a growing interest in head-mounted display (HMD)-based virtual reality (VR) environments,there have been lots of studies enhancing user experience (UX) in the context. In particular, thestudy of motion sickness (MS) symptoms, which are a major barrier to providing a positive UX, isof high importance. This study investigated the effects of degree of freedom (DOF) and field ofview (FOV) of HMD on MS symptoms. A user experiment was designed based on a 2 2 mixeddesign with DOF as a between-subject design variable (3-DOF and 6-DOF) and FOV as a within-subject design variable (Narrow and Wide). Participants experienced VR game content in four con-ditions in random order. MS symptoms were captured using heart rate variability (HRV) and virtualreality sickness questionnaire (VRSQ) at the pre- and post-task moment. The results showed thatMS symptoms occurred more in the 3-DOF condition than in the 6-DOF. Further, MS symptoms inDOF conditions were adjusted depending on the FOV. In the Wide condition, we found a signifi-cant difference in MS symptoms depending on the DOF, but in the Narrow condition, no signifi-cant differences were found. Through this finding, we were able to not only show theeffectiveness of HRV as MS measures but also provide meaningful design insights into HMD-basedVR practices.