Minxin Cheng, Danielle Levac
Rehabilitation Games & Virtual Reality Lab, Department of Physical Therapy, Movement and Rehabilitation Sciences, Northeastern University, Boston, MA, USA
Introduction
Virtual reality (VR) is a popular pediatric rehabilitation intervention. However, much remains to be understood about the impact of child-specific (e.g., motivation, engagement, and cognitive workload) and task-specific (e.g. immersive vs non-immersive viewing medium) influences on motor learning and transfer in VR. Our objectives were to 1) Compare acquisition and retention of the same novel postural reaching task in an immersive VE, a non-immersive VE, and a physical environment; 2) Determine the impact of acquisition environment on transfer between contexts; and 3) Compare children’s motivation, engagement and cognitive workload across the 3 conditions.
Methods
A comparative design assessed performance during an acquisition phase (Session 1; 200 trials) via delayed retention and transfer tests (Session 2; 100 trials; 2-7 days post-acquisition) in 28 typically
developing children aged 8-14 years (mean 11.5, SD 2.1), recruited via social media. Children were randomized to practice the same novel postural reaching task in 3D immersive VR (HTC VIVE Pro), 2D non-immersive VR (Motek Medical Stability & Balance Learning Environment), or a custom-made physical environment (PE). Performance was quantified by mean score (speed and accuracy) per block of 5 trials. Participants completed the Intrinsic Motivation Inventory [IMI], User Engagement Scale [UES], and the NASA Task Load Index [NASA TLX] post-acquisition. Retention tests were performed in the acquisition environment. Children in both VR conditions performed the transfer test in the physical environment, while children who acquired the task in the physical environment were randomized to immersive or non-immersive VR. Mixed effects models compared performance between conditions
within and across sessions, with IMI, UES and NASA TLX score included as predictors in the model.
Results and discussion
Eleven participants acquired the skill in
3D immersive VR, 8 in 2D nonimmersive VR, and 9 in the PE (7 transferred to immersive, 2 transferred to non-immersive). Figure 1 illustrates the lack of significant differences in acquisition or retention performance between conditions. Task acquisition in the PE transferred best to the 3D immersive environment, with poorest
transfer in the opposite direction (3D to PE). There were no differences in motivation, engagement, or cognitive workload between conditions; however, higher self-reported motivation was associated with better acquisition performance, regardless of condition (t[df=27] = -3.06, p = 0.008). While implications are limited by small sample size, study findings suggest the need for more research to explore real-world task-specificity of practice in 3D immersive VR and to evaluate the relationship between motivation and learning in VR.
Conclusions
Rate and extent of novel motor skill acquisition and retention did not differ between immersive
virtual, non-immersive virtual, and a physical environment in typically developing children and youth.