Rate of human motor adaptation under varying system dynamics

We explore the effects of parameters constituting a second order dynamic system on the rate of human motor adaptation while performing a rhythmic dynamic task. In our experiments, participants excite virtual second-order systems at resonance via a haptic interface. After overtraining subjects with a nominal system, we unexpectedly change the system parameters and study the resulting motor adaptation in catch trials. Through four experiment seatings, we demonstrate the effects of dynamic system parameters on human motor adaptation. Results indicate that gain and damping parameters significantly affect the rate of adaptation. In particular, as the effort required to complete the task increases, the rate of adaptation decreases, indicating a trade-off between task performance and the effort required to perform the task.