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MODELING HUMAN REACHING AND GRASPING:
CORTEX, REHABILITATION AND LATERALIZATION
by
Cheol Han
________________________________________________________________________
A Dissertation Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(COMPUTER SCIENCE)
December 2009
Copyright 2009 Cheol Han
Object Description
| Title | Modeling human reaching and grasping: cortex, rehabilitation and lateralization |
| Author | Han, Cheol |
| Author email | cheolhan@gmail.com; cheolhan@usc.edu |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Computer Science |
| School | Viterbi School of Engineering |
| Date defended/completed | 2009-07-14 |
| Date submitted | 2009 |
| Restricted until | Restricted until 11 Mar. 2010. |
| Date published | 2010-03-11 |
| Advisor (committee chair) | Arbib, Michael A. |
| Advisor (committee member) |
Schweighofer, Nicolas Schaal, Stefan Gordon, James |
| Abstract | Reach-to-grasp action is a principal action in our daily lives; writing, eating, and using tools, first of all, start with a reach-to-grasp. Despite abundant experiments and models, underlying mechanism of reach-to-grasp action is still unclear. This study proposed three different models to identifying underlying mechanisms of reach-to-grasp in terms of how action selection facilitates skill learning, how an action is planned, and how a plan is executed.; The first model studied nonlinear interaction between action selection and motor execution. Constraint-induced therapy reverses unilateral effects of stroke in terms of arm use and motor function. If daily uses may form training, motor function may be regained without further expensive therapy (Winstein et al., 2004). Using a computational model, I showed that if affected arm use exceeds a threshold after a certain amount of therapy, effects of stroke may be reversed through daily activities.; The second model is about variability in reach-to-grasp coordination. Contrasting that previous models capture a typical behavior, a new experimental data (Tretriluxana et al.), which researched right-handers' reach-to-grasp directly or detouring to avoid an obstacle, showed that healthy adults do not exhibit this typical reach-to-grasp coordination. I quantized the data and showed existence of distinct coordination patterns. Then extending Hoff-Arbib model (Hoff & Arbib, 1993), I reproduced those different patterns.; The third one hypothesized the role of the motor cortex with its high level coding and low level coding in reaching. Despite abundance of experimental results on the motor cortex, underlying motor control mechanism with a map representation is still in debate, whether the motor cortex encodes reaching movements as movement directions or muscle synergies. Considering that motor control procedure may include coordinates transformation, I hypothesized that the motor cortex contains both coding, where muscle synergies are primary. A biologically plausible cortical model, first, learned a motor output map (projection from the motor cortex to the spinal cord), encoding muscle synergies, and learned a motor input map (projection from supra-motor cortices to the motor cortex) which activates the motor cortex appropriately, aligning a given movement direction to a muscle synergy direction. I called this structure `dual map'. |
| Keyword | individualization; motor control; motor cortex; neuronal coding; rehabilitation; stroke |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m2603 |
| Rights | Han, Cheol |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | http://www.usc.edu/isd/libraries/services/ask_a_librarian/email/ |
| Filename | etd-Han-3183 |
| Archival file | uscthesesreloadpub_Volume44/etd-Han-3183.pdf |
Description
| Title | Page 1 |
| Full text | MODELING HUMAN REACHING AND GRASPING: CORTEX, REHABILITATION AND LATERALIZATION by Cheol Han ________________________________________________________________________ A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (COMPUTER SCIENCE) December 2009 Copyright 2009 Cheol Han |
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