Effects of body visualization on performance in head-mounted display virtual reality

Abstract

Although there are many virtual reality (VR) applications in sports, only a handful of studies visualized the whole body. There is still a lack of understanding, how much of the own body must be visualized in the head-mounted display (HMD) based VR, to ensure fidelity and similar performance outcome as in the real-world. In the current study, 20 young and healthy participants completed three tasks in a real and virtual environment: balance task, grasping task, and throwing task with a ball. The aim was to find out the meaning of the visualization of different body parts for the quality of movement execution and to derive future guidelines for virtual body presentation. In addition, a comparison of human performance between reality and VR, with whole-body visualization was made. Focusing on the main goal of the current study, there were differences within the measured parameters due to the visualization of different body parts. In the balance task, the differences within the VR body visualization consisted mainly through nobody visualization (NB) compared to the other visualization types defined as whole-body (WB), WB except feet (NF), as well as WB except feet and legs (NLF). In the grasping task, the different body visualization seemed to have no impact on the participants' performances. In the throwing task, the whole-body visualization led to higher accuracy compared to the other visualization types. Regarding the comparison between the conditions, we found significant differences between reality and VR, which had a large effect on the parameters time for completion in the balance and grasping task, the number of foot strikes on the beam in the balance task, as well as the subjective estimation of the difficulty for all tasks. However, the number of errors and the quality of the performances did not differ significantly. The current study was the first study comparing sportsrelated tasks in VR and reality with further manipulations (occlusions of body parts) of the virtual body. For studies analyzing perception and sports performance or for VR sports interventions, we recommend the visualization of the whole body in real-time.

Influence of body visualization in VR during the execution of motoric tasks in different age groups

“…Concerning the importance of visual feedback of the own body during motor task completion, throwing in VR was analyzed with several body visualizations and better performance with full-user-body-visualization or visualization of the arms instead of no visualization was found [ 26 ]. That result is in line with the study of balancing [ 27 ], grasping and throwing performance [ 15 ]. Previous studies proved the feasibility of the tasks within VR environments, although [ 28 ] revealed the need of haptic feedback generating problem-free executing of grasping tasks in VR.…”

“…That could affect action characteristics in VR compared to RW and impair transfer in the real world. Otherwise, previously conducted studies showed minor differences between the visual perception in RW and VR, e.g., in eye-tracking [ 11 ], spatial orientation [ 12 – 14 ], as well as analyses of balance, grasping, and throwing performance accompanied with different body visualization types [ 15 ]. Those rare differences conclude that VR is suitable for training applications and sports science research.…”

“…Furthermore, only a small numbers used an HMD for VR-visualization, in which the whole body is visualized due to technological problems (for review, see [ 8 ]). In [ 15 ], the movement executions in VR of young and healthy adults within balancing, grasping, and throwing were quite like RW. To expand the target groups for possible older-aged VR users, it should be investigated whether there occur differences between the performances of younger and elderly adults within virtual environments to optimize VR applications.…”

“…Acting and perceiving within virtual environments by older-aged samples have been rarely made in the VR-research fields, which makes it hard to recommend this tool to its full extent. Besides, it should be clarified whether older-aged users also do not require the whole body visualization for task completion as previously determined [ 15 ].…”

Effects of first- and third-person perspectives created using a head-mounted display on dart-throwing accuracy

“…Although the VE was associated with underestimation of distances, and the 1PP condition with disrupted distance perception, the performance under the 3PP condition was close to that in the real world. A recent study reported higher accuracy in throwing tasks with whole-body visualization in a VE (Pastel et al 2020). Nevertheless, how 1PP and 3PP training affect motor performance in the real world, rather than in the VE, remains poorly understood.…”