Motor Control Theories Part 2 Flashcards
Recall schema updates instructions based on
Recognition schema
Dynamic pattern theory (aka dynamical systems)
Instructions are influenced by environment and interaction of the body, limb and NS
What does dynamic pattern theory describe and explain
Control of coordinated movement emphasizing the role of environmental info and the dynamic properties of body and limbs
3 dynamic pattern theory concepts
- Behaviour changes are sudden and abrupt changes
- Behaviours are self organized
- Behaviours are specified by environmental and characteristics/conditions
Examples of movement based non-linear change
Walking - transition- running
- changes spontaneously as function of specific speed
- Behaviours are specified by environmental and task characteristics/conditions
Perception/action coupling
- performer-environment interaction is necessary
What does performance-environment interaction account for
Skilled performance of open skills
Perception and action
Perception
Detect critical info in environment (sensory input)
Action
Determine movement control features necessary to achieve goal (motor input)
What does behaviours are self organized mean
Specific pattern of limb movement emerges under certain conditions
Resistant to change, likes to be stable
How does pattern of movement self organize
Within the characteristic of environmental conditions and limb dynamics (based on what’s efficient)
4 terms of dynamic pattern theory
Stability
Attractor states
Order parameters
Control parameters
Stability
Behavioural state of a system
Stability of a behaviour
- diff from variability
- stable system will spontaneously return to stable state is perturbed
- doesnt like to be in between (ex. Either walk or run)
Attractor states
A stable state of the motor control system that leads to behaviour according to preferred coordination patterns (like to be in one attractors state or another)
What do stable attractor states include
- Identified by order parameters
- Minimum variability between trials
- Energy efficient
Order parameters
Functionally specific and abstract variables that define the overall behaviour of the system
What do order parameters enable
A coordinated pattern of movement that can be reproduced and distinguished from other patterns
Common examples of order parameters
- Relative phase
- Relative timing
Relative phase
- movement relationship between segments (joints)
0 degrees vs 180 degrees
In phase: same direction
Anti-phase: opposite direction
Relative timing
Represents amount of time for one movement component in proportion to time required to perform the entire movement
Control parameters
Variable that influences the stability and character of the order parameter
What is changing a control parameter used for
To assess the stability of the order parameter
- aspect can be controlled to change the performance
Wha does control parameters determine
Attractor states for patterns of limb movement
Ex. Increasing speed (control parameter) of walking helps determine how stable relative timing (order parameter) is for movement pattern
Examples of control parameters
Direction, force, speed, perceptual info
When using the same walking, running study what are the components when using dynamic pattern theory
Order parameter- relative timing of gait cycle components
Control parameter- speed
Attractor states- walking or running
Why are running and walking not same coordination phase
Different attractor states
As walking speed increased what happens
Walking pattern becomes less stable
Transition phase introduced and new coordination pattern (running) emerges that is more stable
Unit of control
Functional synergies of muscles and joints act together to produce an action
E.g. reaching for object
How do muscle synergies develop
Through practice, experience, or naturally
What happens if perturbation stops one set of muscles (synergy) from working
Another works in its place to compensate and complete the task
E.g. walking with cast then without
Coordination in dynamic pattern theory
- Order parameters set patterns of movement
- control parameters specify movement characteristics in context to be stable in an attractor state
Degrees of freedom in the dynamic pattern theory
Functional synergies used to perform task and compensate for any perturbations
