1. Behavioral Theories of Motor Control
Chapter 3

2. Overview
Now that we’ve looked at response preparation, what happens during the response programming stage?

3. Early Motor Program Theories
Proposed that for each movement to be made, a separate motor program existed and was stored in memory
Two problems:
Storage: Hard drive (brain) could run out of space
Novel responses: How do you respond to an action never done before?

4. Command Center
Decision> appropriate plan retrieved from memory> instructions to rest of body for action

5. Open Loop Systems Open loop
Action plans generated by command center then carried out by the limbs and muscles without modification
Command Center
Action
Mechanical Example:Sending

6. Closed Loop Systems Closed loop
Command center generates action plan that initiates the movement
Feedback is used to modify on-going action
Command
Center
Action
Feedback
Mechanical Example: Thermostat

7. Slow Vs. Rapid Movements
Motor control uses both open and closed loop systems
Movements are planned in advance, initiated & executed with little modification (remember the fake in PRP?)
If a rapid movement, feedback will be used for the next attempt
For slower movements, open loop begins the movement and closed loop will continue to completion

8. Problem: How does a person do a novel motor skill? Motor Program
Abstract representation of a movement plan
Stored in memory
Issues instructions that are carried out by the limbs and muscles

9. Generalized Motor Program (GMP)
Represents a class of actions or pattern of movement that can be modified to yield various response outcomes
Invariant features
Relatively fixed underlying features that define a GMP
Parameters
Flexible features that define how to execute a GMP

10. Fixed vs. Flexible Features
Write your name with the following:
Your dominant hand
Your non-dominant hand
Pen in your mouth
Pressing very hard
Pressing very soft
Write quickly, then slowly
Which aspects were fixed? Flexible?

11. Invariant Features Relatively fixed underlying features
Sequence of actions or components
Relative timing
Internal rhythm of the skill : the amount of time to write each letter of your name will stay the same whether writing fast or slow
Relative force
Internal force relationship: The amount of force given to write each letter stays proportionally the same whether pressing hard or soft

12. Parameters Adaptable features of program
Easily modified from one performance to another to produce variations of a motor response
Overall duration: Fast or slow
Overall force: Hard or soft
Muscle selection: Writing with hand or foot?

13. Review Question
When swimmers use hand paddles or when baseball hitters swing heavier bats, does this manipulate invariant features or parameter features?
When might such an action hinder the development of correct technique?
What signs would you look for to avoid this problem?

14. Schema
Rule or relationship that directs decision-making when a learner is faced with a movement problem
Developed by abstracting 4 sources of information for each performance attempt
Initial conditions present at start of movement
Response specifications: parameters used in the execution of the movement
Sensory consequences: what did the action feel like?
Response outcome: how successful was the response?

15. Schema Development
For each movement attempt the four sources of information are stored in memory briefly
Feedback from the attempt verifies
How successful was the performance?
Do I need to change the movement?
With each additional attempt, the strength of the schema increases when you compare one attempt to the next

16. Motor Response Schema Recall schema Recognition schema
Responsible for organizing the motor program
What do I need to do?>What conditions exist?>What parameters & invariant features are required?>Execute the response
Recognition schema
Responsible for the evaluation of a movement attempt : Was the movement correct?
Error signal updates the recall schema

17. Dynamic System Theory
Movement pattern is thought to emerge or self-organize as a function of the ever-changing constraints placed upon it

18. Constraints
Defined as the boundaries that limit the movement capabilities of an individual
Three types
Organismic: structural or functional
Body type, wt, ht
Psychological, cognitive, emotional
Environmental:wind, light, flat surface, grassy
Task

19. Task Constraints The goal of task: a certain movement
Rules that may limit the movement
One must serve the tennis ball within an area on the baseline
Implements or machines
Using a walker, using weight machines, using a ball

20. Attractor States Systems prefer states of stability
When a change in constraints is imposed on a system, its stability is endangered
Deep basins = stable systems = difficult to change
Shallow basins = less stable = more susceptible to change

21. Phase Shifts Changes in behavior are the result of a series of shifts
Control parameters
Variables that move the system into new attractor states: gaining leg strength to perform a skill better
Rate limiters
Constraints that function to hinder or hold back the ability of a system to change :Adult learner, fear

22. So what happens when a skill performance needs to change?
Practice strategies need to create instability in a deep attractor basin
As the skill moves through the phase shift, it will become a combination of the old and new ways
At some point it will be neither the old or new and performance effectiveness is reduced
Eventually through practice, a new attractor state is formed, and eventually a new deep basin

23. Key Point Movement patterns prefer state of stability
New movements self-organize and emerge with phase shifts where attractors stabilize and destabilize as a function of the control parameters

24. Practical Application
Explain how orthotics function from a dynamic system perspective

25. Exit Slip How do the recall and recognition schema work together?
How are phase shifts indicative of behavioral change?