TY - GEN
T1 - Negative viscosity can enhance learning of inertial dynamics
AU - Huang, Felix C.
AU - Patton, James L.
AU - Mussa-Ivaldil, Ferdinando A.
PY - 2009
Y1 - 2009
N2 - We investigated how learning of inertial load manipulation is influenced by movement amplification with negative viscosity. Using a force-feedback device, subjects trained on anisotropic loads (5 orientations) with free movements in one of three conditions (inertia only, negative viscosity only, or combined), prior to common evaluation conditions (prescribed circular pattern with inertia only). Training with Combined-Load resulted in lower error (6.89±3.25%) compared to Inertia-Only (8.40±4.32%) and Viscosity-Only (8.17±4.13%) according to radial deviation analysis (% of trial mean radius). Combined-Load and Inertia- Only groups exhibited similar unexpected no-load trials (8.38±4.31% versns 8.91±4.70% of trial mean radius), which suggests comparable low-impedance strategies. These findings are remarkable since negative viscosity, only available during training, evidently enhanced learning when combined with inertia. Modeling analysis suggests that a feedforward afte-reffect of negative viscosity cannot predict such performance gains. Instead, results from Combined-Load training are consistent with greater feedforward inertia compensation along with a small increase in impedance control. The capability of the nervous system to generalize learning from negative viscosity suggests an intriguing new method for enhancing sensorimotor adaptation.
AB - We investigated how learning of inertial load manipulation is influenced by movement amplification with negative viscosity. Using a force-feedback device, subjects trained on anisotropic loads (5 orientations) with free movements in one of three conditions (inertia only, negative viscosity only, or combined), prior to common evaluation conditions (prescribed circular pattern with inertia only). Training with Combined-Load resulted in lower error (6.89±3.25%) compared to Inertia-Only (8.40±4.32%) and Viscosity-Only (8.17±4.13%) according to radial deviation analysis (% of trial mean radius). Combined-Load and Inertia- Only groups exhibited similar unexpected no-load trials (8.38±4.31% versns 8.91±4.70% of trial mean radius), which suggests comparable low-impedance strategies. These findings are remarkable since negative viscosity, only available during training, evidently enhanced learning when combined with inertia. Modeling analysis suggests that a feedforward afte-reffect of negative viscosity cannot predict such performance gains. Instead, results from Combined-Load training are consistent with greater feedforward inertia compensation along with a small increase in impedance control. The capability of the nervous system to generalize learning from negative viscosity suggests an intriguing new method for enhancing sensorimotor adaptation.
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U2 - 10.1109/ICORR.2009.5209528
DO - 10.1109/ICORR.2009.5209528
M3 - Conference contribution
C2 - 26380041
AN - SCOPUS:70449347887
SN - 9781424437894
T3 - 2009 IEEE International Conference on Rehabilitation Robotics, ICORR 2009
SP - 474
EP - 479
BT - 2009 IEEE International Conference on Rehabilitation Robotics, ICORR 2009
T2 - 2009 IEEE International Conference on Rehabilitation Robotics, ICORR 2009
Y2 - 23 June 2009 through 26 June 2009
ER -