9604555 Ashe Everyday limb movements can be described both in terms of the forces that the muscles produce and in terms of the more spatial, descriptive aspects of the movement such as trajectory, direction, position, and velocity. The brain controls all aspects of limb movement, but it is not known how the brain codes the different aspects of movement. The basis of this project is the hypothesis that the brain controls both muscle force generated during a movement and the spatial aspects of that movement together by regulating the stiffness (force/position), viscosity (force/velocity) and inertia (force/acceleration) of a moving limb. To test this, the project monitors the activity of cells in the motor control area of the brain during the execution of a trained arm movement performed under different conditions. Sophisticated statistical techniques developed by the experimenters are then used to extract the rules used by cells in this brain area to control arm movements. Potential long-term significance of this work includes the application of the understanding of brain codes for movement to the development of prosthetic devices, the treatment of movement disorders, and the development of robotic systems.
