The role of action observation in prosthesis learning

Abstract

When portions of upper limbs are lost, persons with new amputations must re-learn how to exist within the world. This involves training patients on prosthetic devices that aim to replace limb functionality; however, these prostheses are difficult to use and are often taught poorly. It has been established that the most effective method of teaching prostheses involves having patients observe a teacher who is also using a prosthetic device, but the reasons why are unclear. This work sought to explore the relationship between teacher status and learner outcome through the use of a fictive amputee modeling device (FAMS). Ten subjects attempted to learn use of the FAMS while watching a teacher using their intact limb, and ten subjects attempted the same FAMS task while observing a teacher also using the FAMS. During action observation, gaze positioning was recorded; during action execution, basic kinematic parameters were recorded. Then, kinematic and gaze parameters were examined for how they varied together using canonical correlation analysis. We discovered that those in the matched group had a more streamlined learning process with higher correlation between visual and kinematic variables; on the other hand, the mismatched group experienced a more chaotic learning process with lower correlation between visual and kinematic variables. This suggests that the route to prosthesis learning is more obvious in the presence of a matched teacher, which serves to further emphasize the importance of a matched protocol being the default in a rehabilitation setting.