Table 2.
Task | Input | Parameter measured | Analysis method | |
---|---|---|---|---|
Spiral tracing | Line tracing | f t , M t | Tremor frequency and magnitude | Power spectrum analysis |
Task 1 | Low frequency visual perturbation | Tv | Visual response delay | Cross correlation of subject response with input |
Tv* | Predictive response delay | |||
Task 2 | Low-frequency torque perturbation | Tp | Proprioceptive response delay | Cross correlation of subject response with input |
Tp* | Predictive proprioceptive response delay | |||
Task 3 | Fixed levels of isometric torque | α | Multiplicative motor noise | Linear fit of variance vs. average torque |
Task 4 | High-frequency visual perturbation | J, B, K | Inertia, viscosity, stiffness of arm | Bootstrapped model fit to the subject’s measured frequency response function (FRF) |
J*, B*, K* | Predictive inertia, viscosity, stiffness of arm | |||
Kv, Kp, Kv*, Kp*, Kd, Kpr, Ki | Sensory and Controller gains | |||
Task 5 | Visual offset | RMSE | Movement error | Kinematic analysis |
* indicates predictive values.