Is children's motor learning of a postural reaching task enhanced by practice in a virtual environment?

To support the use of virtual environments (VEs) in pediatric rehabilitation, greater understanding of the extent and mechanisms by which practice in a VE might facilitate motor learning as compared to practice in a physical environment (PE) is required. One proposed mechanism is via enhanced user engagement and/or motivation, which may directly influence the quality of motor memory consolidation. The objectives of this study were to a) compare children's motor learning of the same novel postural reaching task in a VE versus a PE; b) evaluate differences in engagement and motivation between the two practice environments; and c) explore the relationships between practice environment, engagement, motivation, and motor learning. Thirty-six typically developing children aged 7-13 years were randomized to acquire a novel postural reaching skill in either a 2D flat-screen VE or a PE. Skin conductance level (SCL) was measured on the non-task hand during practice. Following acquisition, children completed a language-modified User Engagement Scale (UES) and the Pediatric Motivation Inventory (PMOT). Participants returned 1-7 days later for retention (same environment) and transfer (opposite environment) tests. Children who practiced in the VE demonstrated greater retention, as evidenced by higher mean scores on the retention test (t[30] = -3.72, p = 0.001, partial eta squared 0.28). Children who practiced in the PE demonstrated greater transfer to the opposite environment as compared to those who practiced in the VE (t[30] = 2.05, p = 0.001, partial eta squared = 0.238). There were no significant differences in UES total or subscale scores between the 2 groups. PMOT total motivation scores differed significantly between groups, favoring the VE (t[30]= 2.49, p = 0.018, partial eta squared = 0.154). There were no significant differences in SCL peak count or peaks per minute between groups. There was no relationship between engagement, motivation, and retention or transfer performance. Findings suggest that retention but not transfer of a new motor skill may be facilitated by practice in a VE. This may be due to unique task demands in each environment. Children were more motivated to succeed in the VE and were engaged in the task in both environments, suggesting that both constructs should be measured in subsequent studies and that VE aesthetics alone may not be a key `active ingredient' of children's engagement. Subsequent research will more objectively quantify neurophysiological correlates of engagement and motivation, explore additional tasks, include populations with neurological impairments and compare 3D vs 2D VE displays.