Seminar
Title: |
Standing in balance: translating motor intentions into motor commands in animals, humans, and robots |
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Speaker: |
Dr. Lena Ting |
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Affiliation: |
Georgia Tech, Biomedical Engineering |
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When: |
Wednesday, September 23, 2009 at 11:00:00 AM |
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Where: |
MARC Building, Room Auditorium |
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Host: |
Andres Garcia | |
Abstract How do humans and animals move so elegantly through unpredictable and dynamic environments? And why does this question continue to pose such a challenge? We have a wealth of data on the action of neurons, muscles, and limbs during a wide variety of motor behaviors, yet these data are difficult to interpret, as there is no one-to-one correspondence between a desired movement goal, limb motions, or muscle activity. Using combined experimental and computational approaches, we are teasing apart the neural and biomechanical influences on muscle coordination of during standing balance control in cats and humans. Our work demonstrates that variability in motor patterns both within and across subjects during balance control in humans and animals can be characterized by a low-dimensional set of parameters related to abstract, task-level variables. Temporal patterns of muscle activation across the body can be characterized by a 4-parameter, delayed-feedback model on center-of-mass kinematic variables. Moreover, over a period of learning, subject improve their response to resemble that predicted by an optimal tradeoff between mechanical stability and energetic expenditure. Spatial patterns of muscle activation can also be characterized by a small set of muscle synergies (identified using non-negative matrix factorization) that are like motor building blocks, defining characteristic patterns of activation across multiple muscles. We demonstrate that each muscle synergy performs a task-level function, thereby providing a mechanism by which task-level motor intentions are translated into detailed, low-level muscle activation patterns. Using musculoskeletal simulations and robotic approaches, we demonstrate how biomechanical properties of the limb and body constrain our patterns of movement, but at the same time also for flexibility and robustness that may lead to individual differences in how we move. |
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Biography Dr. Ting is an Associate Professor in the W.H. Coulter Department of Biomedical Engineering at Emory University and Georgia Institute of Technology. Her area of research is in neuromechanics, focusing on the sensorimotor interactions between brain, body, and environment at the level of muscular coordination during balance and gait in humans and animals. She received a B.S. in Mechanical Engineering at the University of California at Berkeley, an M.S.E. in Biomechanical Engineering and Ph.D. in Mechanical Engineering from Stanford University. She received postdoctoral training in neurophysiology at the University of Paris V, and Oregon Health and Sciences University. She currently serves as regular member on the NIH review panel on Sensorimotor Integration (SMI). She received a Junior Faculty Teaching Award from Georgia Tech Center for the Enhancement of Teaching and Learning in 2006. In 2007 she received the Arthur C. Guyton Award for Excellence in Integrative Physiology from the American Physiological Society, recognizing an individual demonstrating outstanding promise based on his/her research program in feedback control systems, quantitative modeling, and integrative physiology. In 2008, she was a Miller Visiting Professor at the University of California at Berkeley. |
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Notes |
Refreshments will be served. |
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