Goal-oriented feedback on motor behavior in virtual reality based stroke therapy: A case study using the rehabilitation gaming system

Abstract

Aims: We address the role of short-term goals in virtual reality (VR) applications for motor relearning, which benefit stroke therapy. Methods: We let stroke patients as well as healthy participants perform reaching tasks in a VR environment for motor rehabilitation, the so-called rehabilitation gaming system (RGS). During the task, patients were provided with feedback about one´s own performance (mastery goal), healthy participants additionally received feedback of others performances (ego goal). Measurements include protocols for motor learning and different kinetic variables (both stroke patients and healthy participants) as well as subscales of the intrinsic motivation inventory (IMI) (only healthy participants). As healthy participants showed lower fatigue levels, we could apply additional measurements. Result: Both mastery goals and ego goals potentially enhance intrinsic motivation and adherence, as they show to foster task performance (e.g., response time in mastery goals decreased with p = 0.014 for healthy participants, for stroke patients with p = 0.011 in the first iteration) as well as perceived effort (p = 0.007 for mastery, p = 0.008 for ego goals). As a secondary outcome, by controlling task difficulty, motor learning does not change across conditions (p = 0.316 for stroke patients, p = 0.323 for healthy participants). This raises the question whether or not task difficulty alone fosters the effectivity of VR based therapy applications, i.e., motor learning, to which motivators such as short-term goals provide little trade-off. Conclusion: Firstly, we suggest the implementation of mastery and ego goals in VR based stroke therapy, as adherence benefits from the motivational context they provide. Secondly, we argue towards simplicity regarding heuristics in therapeutic game design, which apparently often does not differ from conventional game design apart from setting the right level of challenge.