Analogous adaptations in speed, impulse and endpoint stiffness when learning a real and virtual insertion task with haptic feedback

Atsushi Takagi,Etienne Burdet,Jonathan Savin,Hiroyuki Kambara,Yasuharu Koike,Giovanni De Magistris,Geyun Xiong,Jacques Marsot,Alain Micaelli

doi:10.1038/s41598-020-79433-5

Abstract

Humans have the ability to use a diverse range of handheld tools. Owing to its versatility, a virtual environment with haptic feedback of the force is ideally suited to investigating motor learning during tool use. However, few simulators exist to recreate the dynamic interactions during real tool use, and no study has compared the correlates of motor learning between a real and virtual tooling task. To this end, we compared two groups of participants who either learned to insert a real or virtual tool into a fixture. The trial duration, the movement speed, the force impulse after insertion and the endpoint stiffness magnitude decreased as a function of trials, but they changed at comparable rates in both environments. A ballistic insertion strategy observed in both environments suggests some interdependence when controlling motion and controlling interaction, contradicting a prominent theory of these two control modalities being independent of one another. Our results suggest that the brain learns real and virtual insertion in a comparable manner, thereby supporting the use of a virtual tooling task with haptic feedback to investigate motor learning during tool use.

Highlights

Humans have the ability to use a diverse range of handheld tools
If the motor learning in a virtual environment is comparable to that in a real environment, this raises the possibility of accelerating the training of novices by having them practice in a virtual environment prior to the real task
The correlates of motor learning we focused on were the trial duration, the movement speed, the force impulse and the endpoint stiffness magnitude

Summary

Introduction

Humans have the ability to use a diverse range of handheld tools. Owing to its versatility, a virtual environment with haptic feedback of the force is ideally suited to investigating motor learning during tool use. Correlates of motor learning e.g., reduced force, are confounded by the changing dynamics of the task in a real environment These confounds can be avoided by investigating motor learning of an insertion task in a virtual environment where the dynamics of the tool and the materials are not subject to degradation after repeated use. A virtual environment poses other advantages, such as freedom in manipulating the dimensions of the tool[8], and the ability to control the dynamics of the interaction with precision and to observe the progress of motor learning It is unclear whether the behavior of participants learning a virtual insertion task is comparable to those learning real insertion. If the motor learning in a virtual environment is comparable to that in a real environment, this raises the possibility of accelerating the training of novices by having them practice in a virtual environment prior to the real task

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Conclusion