BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Memento EPFL// BEGIN:VEVENT SUMMARY:Learning the environment as compatible forces and motions DTSTART:20161212T163000 DTEND:20161212T173000 DTSTAMP:20260407T084952Z UID:e917d11f2eb627424cac8a7102b4e16c266e1f3d455c1a13651a7934 CATEGORIES:Conferences - Seminars DESCRIPTION:Prof. F. A. Mussa-Ivaldi\, Rehabilitation Institute of Chicag o\, USA.\nThe goal of recovering the desired behavior against external per turbations can be achieved by feedback mechanisms. When the environment is unpredictable\, the maintenance of a desired motion or a desired contact force by feedback mechanisms can be accomplished by shifting the interface impedance toward two opposing limits. In motion control\, random forces a re counteracted by high position feedback gains\, resulting in high contac t impedance. In force control\, random motions are compensated by high for ce feedback gains\, resulting in low contact impedance. \n\nThe possibili ty to shift impedance toward high or low values is constrained by the pass ive mechanics of muscles and bones and by the long transmission delays of neural feedback.  However\, when the environment acts upon us in a predic table way\, our brain may form internal representations of the external me chanics and modify the feedforward commands accordingly.  This leads to a n adaptive response that has been extensively investigated in the generati on of movements against predictable force fields.\n\nI will consider this issue in a theoretical framework that extends the concept of internal mode ls and unifies the approach to the motor learning of forces and motions.   In this framework\, the brain generates a vast spectrum of interactive behaviors by combining two independent processes. One is competent to cont rol movements in free space and the other is competent to control contact forces against rigid constraints. Free space and rigid constraints are sin gularities at the boundaries of a continuum of mechanical impedance. Withi n this continuum\, forces and motions occur in "compatible pairs" connecte d by the equations of Newtonian dynamics.  The force applied to an object determines its motion. Conversely\, inverse dynamics determine a unique f orce trajectory from a movement trajectory. In this perspective\, motor le arning is a process that leads to representing the environment dynamics th rough the discovery of compatible force/motion pairs.\n\n\nBio: Ferdinando A. (Sandro) Mussa-Ivaldi was born in Torino\, Italy. He has a degree (Lau rea) in physics from the University of Torino\, Torino\, Italy\, in 1978\, and the Ph.D. degree in biomedical engineering from the Politecnico of Mi lano\, Milan\, Italy\, 1987. He is a Professor of Physiology\, Physical Me dicine and Rehabilitation and Biomedical Engineering at Northwestern Unive rsity. He is founder and Director of the Robotics Laboratory of the Rehabi litation Institute of Chicago. His areas of interest and expertise include robotics\, neurobiology of the sensory-motor system and computational neu roscience. Among his scientific achievements are the first measurement of human arm multi-joint impedance\, the development of a technique for inves tigating the mechanisms of motor learning through the application of deter ministic force fields\, the discovery of a family of integrable generalize d inverses for redundant kinematic chains\, the discovery of functional mo dules within the spinal cord that generate a discrete family of force-fiel ds\, the development of a theoretical framework for the representation\, g eneration and learning of arm movements and the development of the first n eurorobotic system in which a neural preparation in vitro—the brainstem of a lamprey—controls the behavior of a mobile-robot through a closed-lo op interaction.\n\nIn the last two decades\, he has worked toward understa nding the mechanisms of motor learning and how these mechanisms can be use d to help people recover from disability. He investigates motor learning\, not merely as a mechanism to improve particular skills\, but as a means f or the brain to adapt the control a body that changes in a variable enviro nment. Recently\, he has developed the concept of the body–machine inter face as an instrument to facilitate the reorganization of movement to cont rol devices such as wheelchairs and computers. He is the author of over 15 0 full-length publications. Dr. Mussa-Ivaldi is a member of the Society fo r Neuroscience and of the Society for the Neural Control of Movement.\n  LOCATION:Campus Biotech H4 1 232.082 https://www.google.com/maps?ll=46.222 294\,6.148447&z=16&t=m&hl=en-US&gl=GB&mapclient=embed&cid=1601697153472773 779 STATUS:CONFIRMED END:VEVENT END:VCALENDAR