Priors Engaged in Long-Latency Responses to Mechanical Perturbations Suggest a Rapid Update in State Estimation
Figure 3
A: Overhead representation of the initial joint configuration and of a typical perturbation related movement. The initial joint configuration is shown in black. Hand path from perturbation onset until the first hand-speed minimum (TH) is represented in solid trace. The remaining portion of the corrective movement is shown in dashed trace. B: Illustration of the different torque profiles: black traces illustrate the step perturbations (1 Nm and 3 Nm are displayed with thin traces), ramp-down perturbations in red and ramp-up perturbations in blue. C: Schematic representation of the effect of a ramp-down perturbation profile on the state estimation: the overestimation (gray region) result from the difference between the expected perturbation profile (step-function, dashed) and the actual perturbation (solid). The ramp-down profile was designed to produce an overestimation as illustrated in Figure 1 C. The opposite reasoning applies to ramp up-perturbation that produces an underestimation of the present state of the joint.