Concepts of Motor Organization

INTRODUCTION 328 Part 1. CENTRALLY PROGRAMMED MOVEMENT 328 Proprioception and Active Movement 330 Alpha-Gamma Coactivation 331 Central Driving of Sensory Relay Neurons 333 Feedback to Motor Cortex 335 Part 2. CONTROL SYSTEM MODELS AND ADAPTIY.E GAIN CONTROL 337 Open-Loop Control 337 Adaptive Gain Control 338 Closed-Loop Control 342 Steady-state errors 344 Dynamic errors ond stability 345 Use of damping to improve stability 345 Use of feedforward to improve dynamic responses 345 Use of postive feedback to reduce steady-state errors 347 The stabilization of retinal images: A preliminary model 349 Ocular pursuit of small moving targets (head stationary) 350 Head turns while fixating stationary targets 350 Combined eye-head tracking 351 Part 3. EFFERENCE COPY AND COROLLARY DISCHARGE 352 Visuomotor Coordination 352 Perceptual Stability 354 Perceptual versus Motor Localization 356 Sensations Attributable to Impulses Arising in Muscle Stretch Receptors 356 Gamma Motoneuron Discharge Viewed as EJference Copy 357