Influence of model parameters on the simulated optimal movements.

The model parameters that were varied are σi, qvar and β. Effort is the integral cost in the control variable u(t). EP std is the final standard deviation of the endpoint along the x-axis, and is the mean endpoint stiffness along the x-axis. Sensitivity of the results to increasing the magnitude of the force field, increasing noise or increasing qvar is tested. Note that the model predicts an increase of the lateral endpoint stiffness on average to perform the task accurately in open-loop (~2x factor in these simulations).