Seminar Details
2008-01-08 (14.00) : An Introduction to Dynamic Encoding
At Euler building
Organized by Mathematical Engineering
Speaker :
Ignasi COS-AGUILERA
(HWNI, UC Berkeley, USA)
Abstract :
The Brain Machine Interface paradigm relies on cortical adaptivity to
generate and control movement of an external device. In particular,
previous experiments have demonstrated the validity of motor brain areas
for controlling a cursor on a computer screen with the help of visual
feedback. However, these approaches lack control of every parameter
involved in the motion of a physical object, the parameters controlling
the dynamics of the movement: inertia, stiffness and viscosity.
In a complementary fashion to this main stream, we argue that decoding of those parameters from the cortex is the most natural
procedure to control a prosthetic device. Eventually, dynamic control should be the one requiring the least effort to adapt to.
From this perspective, we have been studying the procedures of control of movement within force-field conditions via psychophysical
experiments, aiming at understanding the adaptation process of the brain to situations requiring accountancy of the dynamics of motion.
The experiments demonstrate different strategies to cope with different force-field conditions, suggesting that once adaptation is complete,
movement is controlled via modulation of impedance. Stiffness, viscosity and intertia are optimized according to the position and type of reach.
We present some of these experiments together with a prospect of future research.