Duality Approach to Minimum-variance End-point Error Model of Voluntary Movement

In this paper, a dual problem of the motor control model based on the signal-dependent noise hypothesis is addressed. First, the motor control model including signal-dependent noise is reduced to an optimal control problem whose cost function contains a time-varying weight. Then an estimation problem under the time-varying output noise model is introduced as the dual problem of the motor control model mentioned above, and it is proven that this time-varying noise can be interpreted as a signal-dependent output noise. Finally it is shown by experimental results that the model of the estimation based on the signal-dependent noise does not qualitatively contradict to the estimation performed by human beings on some situations.