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•
Dynamics
Dynamics
–
–
changes in behavior during a
changes in behavior during a
period of time
period of time
•
Dynamical systems
Dynamical systems
– a complex system
– a complex system
that produces changes in behavior patterns
that produces changes in behavior patterns
during a period of time – often in a
during a period of time – often in a
nonlinear way
nonlinear way
•
Dynamic Pattern Theory
Dynamic Pattern Theory
– a theory
– a theory
concerned with identifying the physical laws
concerned with identifying the physical laws
that govern the changes in behavior
that govern the changes in behavior
patterns produced by a complex system
patterns produced by a complex system
Ecological Theories:
Ecological Theories:
Dynamic Pattern
Dynamic Pattern
Theory
Theory

An Example of a Self-
An Example of a Self-
Organizing
Organizing
System
System
in Nature
in Nature

•
A coordinated movement pattern is:
A coordinated movement pattern is:

A preferred state
A preferred state
rather
rather
then a state
then a state
specified by a memory representation
specified by a memory representation

Specified by
Specified by
environmental and task
environmental and task
characteristics/conditions
characteristics/conditions

Self-organized
Self-organized
according to an
according to an
attractor
attractor
state
state
Dynamical Pattern Theory
Dynamical Pattern Theory
Terms
Terms

•
Characterized by
Characterized by
2 concepts
2 concepts
:
:

Stability
Stability
: a preferred state that exhibits
: a preferred state that exhibits
invariance; a stable system will return to it
invariance; a stable system will return to it
’
’
s
s
state of stability after it is disrupted or
state of stability after it is disrupted or
perturbed
perturbed

instability can occur between phase transitions
instability can occur between phase transitions

Attractor states
Attractor states
: a stable steady state of the
: a stable steady state of the
motor control system that leads to behavior
motor control system that leads to behavior
according to preferred coordination states
according to preferred coordination states

Change from one state to another is
Change from one state to another is
non-
non-
linear
linear

the change is abrupt the change is abrupt
Dynamic Pattern Theory Terms
Dynamic Pattern Theory Terms
(cont
(cont
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d)

•
Characteristics of an attractor state:
Characteristics of an attractor state:

Identified by
Identified by
order parameters
order parameters
•
e.g
e.g
., relative phase (finger exercise)
., relative phase (finger exercise)

Order parameters are influenced by
Order parameters are influenced by
contro
contro
parameters
parameters
•
e.g
e.g
., speed (stick shift)
., speed (stick shift)

Minimum trial-to-trial variability
Minimum trial-to-trial variability

Stability
Stability

Energy efficient
Energy efficient
Dynamic Pattern Theory Terms
Dynamic Pattern Theory Terms
(cont
(cont
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d)