Kadiallah, A and Liaw, G and Kawato, M and Franklin, DW and Burdet, E (2011) Impedance control is selectively tuned to multiple directions of movement. Journal of Neurophysiology, 106. pp. 2737-2748. ISSN 0022-3077Full text not available from this repository.
Humans are able to learn tool-handling tasks, such as carving, demonstrating their competency to make movements in unstable environments with varied directions. When faced with a single direction of instability, humans learn to selectively co-contract their arm muscles tuning the mechanical stiffness of the limb end point to stabilize movements. This study examines, for the first time, subjects simultaneously adapting to two distinct directions of instability, a situation that may typically occur when using tools. Subjects learned to perform reaching movements in two directions, each of which had lateral instability requiring control of impedance. The subjects were able to adapt to these unstable interactions and switch between movements in the two directions; they did so by learning to selectively control the end-point stiffness counteracting the environmental instability without superfluous stiffness in other directions. This finding demonstrates that the central nervous system can simultaneously tune the mechanical impedance of the limbs to multiple movements by learning movement-specific solutions. Furthermore, it suggests that the impedance controller learns as a function of the state of the arm rather than a general strategy. © 2011 the American Physiological Society.
|Uncontrolled Keywords:||Adaptation Internal model Stiffness Unstable dynamics|
|Divisions:||Div F > Computational and Biological Learning|
|Depositing User:||Cron job|
|Date Deposited:||04 Feb 2015 22:35|
|Last Modified:||05 Feb 2015 07:57|