The role of skill level and motor task characteristics on the effectiveness of robotic training: first results

There is an initial body of work that compared the effectiveness of robotic strategies that amplify or reduce movement errors on motor learning. However, these comparative studies still show inconclusive results, probably because they searched for the robotic strategy that enhances learning, independently of the subjects' skill level and the specific characteristics of the task to be learned. Some theories have suggested that optimal learning is achieved when the difficulty of the task is appropriate for the individual subject's level of expertise. Additionally, the specific characteristics of the task to be learned (e.g. the task's timing component) might play an important role on the effectiveness of different training strategies. In this paper, we overview the research performed in the Sensory-Motor System laboratory at ETH Zurich that aims to find the robotic strategies that could enhance motor learning based on the participants' skill level and specific characteristics of the task to be learned. We performed several motor learning experiments and found that haptic guidance seems to be particularly helpful for initially less skilled subjects, while error amplification is more beneficial for skilled subjects. The rhythmicity and duration of the movement also seem to be key factors to consider when selecting the robotic training strategies that enhance motor learning. The impacts of these training strategies on neurological patients need further investigations.