Synergy

by Mark L. Latash

Overview

Synergy discusses a general problem in biology: The lack of an adequate language for formulating biologically specific problems. Written for an inquisitive reader who is not necessarily a professional in the area of movement studies, this book describes the recent progress in the control and coordination of human movement. The book begins with a brief history of movement studies and reviews the current central controversies in the area of control of movements with an emphasis on the equilibrium-point hypothesis. An operational definition of synergy is introduced and a method of analysis of synergies is described based on the uncontrolled manifold hypothesis. Further this method is used to characterize synergies in a variety of tasks including such common motor tasks as standing, pointing, reaching, standing-up, and manipulation of hand-held objects. Applications of this method to movements by persons with neurological disorders, persons with atypical development and healthy elderly persons are illustrated, as well as changes in motor synergies with practice. Possible neurophysiological mechanisms of synergies are also discussed with the focus on such conspicuous structures as the spinal cord, the cerebellum, the basal ganglia, and the cortex of the large hemispheres. A variety of models are discussed based on different computational and neurophysiological principles. Possible applications of the introduced definition of synergies to other areas such as perception and language are discussed.

Product Details

ISBN-13:	9780199715565
Publisher:	Oxford University Press
Publication date:	03/18/2008
Sold by:	Barnes & Noble
Format:	eBook
File size:	3 MB

Table of Contents

PrefacePart I: Building a Definition for Synergy1.1. Synergies and Non-synergies: A Few Examples1.2. Palama's Concept of Synergy1.3. Inanimate "synergies": The Table and the Rusty Bucket1.4. Examples of Biological Synergies1.5. The Definition: Three Components of a SynergyPart II: A Brief History of Movement Studies2.1. The Ancient Greece and Rome2.2Renaissance. 2.3. The Century of Frogs, Photography, and Amazing Guesses2.4. The XX-th Century: Wars of Ideas2.5. Nikolai Alexandrovich Bernstein and Movement Science in the Soviet Union2.6. History of Synergies and the Problem of Motor Redundancy2.7. Problems with Studying Biological MovementPart III: Motor Control and Coordination3.1. Israel Gelfand and Michael Tsetlin3.2. Structural Units and the Principle of Minimal Interaction3.3. Motor control: Programs and Internal ModelsDigression #1: The Muscle: Slow and Visco-elastic.Digression #2: Neural pathways: Long and Slow.Digression #3: Sensors: Confusing and Unreliable.Digression #4: Adaptation to Force Fields and after-effectsDigression #5: Brain Imaging Techniques: What do they Image?3.4. Motor Control: The Equilibrium-point hypothesis3.4.1 Experimental Foundations of the Equilibrium-point hypothesisDigression #6: Reflexes and non-reflexes3.4.3 Three basic trajectories within the equilibrium- point hypothesis3.4.4 Equilibrium-point control of multi-muscle systems3.4.5. The mass-spring analogy and other misconceptionsPart IV: Motor Variability - a Window into Synergies4.1. The Uncontrolled Manifold Hypothesis4.2. Modes as Elemental Variables4.2.1. Force ModesDigression #7: Digit Interaction and its Indives4.2.2. Muscle ModesDigression #8: Electromyography4.2.3. Experimental Identification of the Jacobian4.3. Stability, Variability, and within-a-trial Analysis of Synergies4.4. Other Computational Tools to Study Synergies4.4.1. PCA &UCM4.4.2. Analysis of Surrogate Data Sets4.5. Timing Synergies: Do they exist?Part V: Zoo of Motor Synergies 5.1. Kinematic synergies5.1.1. Postural Synergies in Standing5.1.2. Sit-to-Stand (STS) Task5.1.3. ReachingDigression #9: Optimization5.1.4. Reaching in a Changing Force Field5.1.5. Multi-Joint Pointing5.1.6. Quick-Draw Pistol Shooting5.2. Kinetic synergies5.3. Multi-Digit Synergies5.3.1. Force and Moment Stabilization during Multi-Finger Pressing5.3.2. The Role of Timing Errors5.3.3. Emergence and Disappearance of Synergies5.3.4. Anticipatory Synergy Adjustments and Purposeful Destabilization of Performance5.4. Prehensile Synergies5.4.1. Hierarchical Control of Prehension5.4.2. Principle of Superposition5.4.3. Adjustments of Synergies: Chain Effects5.4.4. Hierarchies of Synergies5.5. Multi-muscle Synergies5.5.1. Anticipatory Postural Adustments5.5.2. Making a StepPart VI: Atypical, Suboptimal, and Changing Synergies6.1. Is there a "normal synergy"? 6.2. Principle of Indeterminicity in Movement Studies6.3. Plasticity in the Central Nervous SystemDigression #10: Transcranial Magnetic Stimulation6.4. Changes in Synergies with Age6.4.1. Effects of Age on Muscles and Neurons6.4.2. Effects of Age on Motor Coordination6.5. Synergies in Persons with Down syndrome6.5.1. Movements in Persons with Down syndrome6.5.2. Multi-finger Coordination in Down syndrome6.5.3. Effects of Practice on Movement in Down syndrome6.5.4. Relation of Unusual Synergies to Changes in the Cerebellum6.6. Synergies after Stroke6.7. Learning Movement Synergies6.7.1. Traditional Views on Motor Learning6.7.2. What can happen with a Synergy with Practice?6.7.3. Practicing Kinematic Tasks6.7.4. Practicing Kinetic Tasks6.7.5. Plastic Changes with Learning a SynergyPart VII: Neurophysiological Mechanisms of Synergies7.1. Neurophysiological Structures and the Motor FunctionDigression #11: What is localized in Neural Structures?7.2. Synergies in the Spinal Cord7.3. Synergies and the Cerebellum7.4. Synergies and the Basal Ganglia7.5. Synergies and the Cortex of the Large Hemispheres7.5.1. TMS and the equilibrium-point hypothesis7.5.2. Studies of Neuronal PopulationsPart VIII: Models and Beyond Motor Synergies8.1. Synergies and the Control Theory8.1.1 Control: Basic Notions8.1.2. Open-loop and Closed-loop (feed-forward and feeback) Control8.1.3. A Simple Scheme of Synergic Control of a Multi-joint Movement8.1.4. Optimal Control and Synergies8.2. Synergies and Neural Networks8.3. Synergies Without Feedback8.3.1. Do Synergies Improve Accuracy?8.3.2. A Feed-forward Model with Separate Specification of Good and Bad Ariability8.4. Synergies and the Equilibrium-point Hypothesis8.5. Sensory Synergies8.5.1. Sensory synergies in Neurological DisordersDigression #12: Sensory and Motor Effects of Muscle Vibration8.5.2. Sensory-motor Interactions8.5.3. Sensory Synergies in Vertical Posture8.5.4. Multi-sensory Mechanisms8.6. Language as a Synergy8.7. Concluding Comments: What next?References