Ch 5 Motor Learning Theories

Only available on StudyMode
  • Download(s) : 177
  • Published : October 29, 2012
Open Document
Text Preview
Chapter 5 – Motor Control Theories
Concept: theories about how we control coordinated movement differ in terms of the roles of central and environmental features of a control system

Theory and Professional Practice
* What is a theory?
* Accurately describes a large class of observations
* Make definite predictions about results of future observations * Theories of motor learning and control focus on:
* Explaining human movement behavior
* Providing explanations about why people perform skills as they do * Does a theory have relevance to professional practice?
* Provides the “why” basis for what practitioners do (see fig 5.1) Motor Control Theory
* Describes and explains how the nervous system produces coordinated movement of motor skill in a variety of environments * Two important terms:
* Coordination
* Patterning of body and limb motions relative to the patterning of environmental objects and events * Two parts to consider:
* Movement pattern of a skill in relationship at a specific point in time * Context of the environment of the head, body, and/or limb movements so the actions can be accomplished * The degrees of freedom problem

* Degrees of freedom (df) = number of independent elements in a system and the ways each element can act * E.g. the control of a helicopter’s flight (described in the textbook) * Degree of freedom problem for the control of movement: * How does the nervous system control the many df of muscles, limbs, and joints to enable a person to perform an action as intended? Two General Types of Control Systems

* Open- and Closed-Loop Control Systems
* See fig 5.3
* Incorporated into all theories of motor control
* Models of basic descriptions to show different ways the CNS and PNS initiate and control action * Each has a central control center (executive)
* Function to generate and forward movement instructions to effectors (i.e., muscles) * Each includes movement instructions from control center to effectors * Content of the instructions differs between systems

Differences between the Systems
* Two differences
* Open-loop
* Does not use feedback
* Control center provides all the information for effectors to carry out movement * Does not use feedback to continue and terminate movement * Closed-Loop
* Uses feedback
* Control center issues information to effectors sufficient only to initiate movement * Relies on feedback to continue and terminate movement Two Theories of Motor Control
* Motor program-based theory:
* Memory-based mechanism that controls coordinated movement * Best example comes from “Schema Theory” by Schmidt (1988) * Generalized motor program (GMP):
* Hypothesized memory-based mechanism responsible for adaptive and flexible qualities of human movement * Proposed that each GMP controls a class of actions that have common invariant characteristics * GMP function

* To serve as the basis for generating movement instructions prior to and during the performance of an action * GMP Characteristics
* Two classes
* Invariant features
* Characteristics of the GMP that do not vary across performances of a skill within class of actions * The identifying action signature of a GMP * Example

* Relative time of the components of an action (i.e., % of total time each component uses during performance) * Parameters
* Specific movement features added to the invariant features to enable the performance of a skill in a specific situation * Characteristics can vary from one performance of a skill to...
tracking img