0000000000338052
AUTHOR
Marie Barbiero
Improving operational performance in altered gravity
Human motor adaptation is crucial to remain efficient when exposed to unfamiliar environments. In these contexts, the efficient strategies developed by the brain to optimise movement can prove deficient. Dexterous manual movement execution in space therefore require the learning of new coordinated motor actions. Traditionally, adaptation mechanisms are tested in laboratory using robotic devices that disturb the limb specifically involved in the task while the dynamics of the rest of the body remain unchanged. Although participants build a more accurate representation of the task over repetitions, these approaches are limiting as they do not reflect the ecological adjustment to globally modi…
Smart switching in feedforward control of grip force during manipulation of elastic objects
AbstractSwitching systems are common in artificial control systems. Here, we suggest that the brain adopts a switched feedforward control of grip forces during manipulation of objects. We measured how participants modulated grip force when interacting with soft and rigid virtual springs when stiffness varied nearly continuously between trials. We identified a sudden phase transition between two forms of feedforward control that differed in the timing of the synchronization between the anticipated load force and the applied grip force. The switch occurred several trials after a threshold stiffness level. These results suggest that in the control of grip force, the brain acts as a switching c…