Transcript Information Processing in Motor Learning

Information Processing
in Motor Learning
Chapter 17
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Outline

Structure and function of
the nervous system

Information processing
and making decisions

Feedback in movement
control

Factors affecting
information processing
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Structure and Function of the
Nervous System
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CNS
Control center
PNS
Connects CNS
with the rest of
the body
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The Neuron and Its Function
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Neuron

Nerve cell

The fundamental functional and structural unit
of the nervous system

Allows information to travel throughout the
body to various destinations
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Receptive
Segment
Cell Body
Dendrites:
receive message
Myelin sheath
Conductive
Segment
Axon:
Nodes of
Ranvier
Transmissive
Segment
transmits
message to
terminal
ending
Terminal ending on muscle:
sends off message to adjacent neuron
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Motor end plate
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Myelin sheath:
fatty covering or
insulator
Skipping of the impulse
allowing faster
conduction
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Types of Neurons
Afferent neurons
Sensory
Carry signals to the
brain
Interneurons
Originate and terminate
in CNS
Connect afferents and
efferents in CNS
CNS tissue cross-section
Efferent neurons
Motor
Carry signals from the
brain
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Types of Neurons cont.
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The Neuron’s Function
Receptive

Receptive segment (dendrites)
– Receives continuous synaptic input
(chemical) from other neurons

Conductive segment (axon)
– Conduction of neural information in
the form of nerve impulse (electrical)
Conductive

Transmissive segment (axon
terminals)
– Converts electrical nerve impulse to
chemical form (neurotransmitter)
and sends it off to synapse
Transmissive
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Neural Impulses



Transport the information necessary for all activities
we carry out
The language of the nervous system
Relay of impulse within neuron:
Rest:
polarization
Membrane potential =
-70 mV
Stimulus:
depolarization
Rest:
polarization
(mV)
+50
Action Potential
+40 mV
0
-50
Resting Potential
-100
Stimulus
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The Synapse and Synaptic Transmission
SYNAPSE
SYNAPTIC
TRANSMISSION
OO O
O O O
. : :.. …. ……
…..:: : .
: .:.;. . .
O O
O
O
•Differ in terms of :
•Neurotransmitter used
(e.g., acetylcholine or Ach)
•General function (e.g.,
inhibitory vs.excitatory)
NEUROTRANSMITTER
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The Synapse and Synaptic Transmission

“All-or-none” law
– Synaptic transmission causes action potential when
its strength is above a minimum threshold level
– Below threshold level = NO action potential
– Action potential is always the same intensity
regardless of the strength of synaptic transmission
above the threshold level
– Action potential intensity remains constant along
the nerve fibre
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STIMULUS
Indication of Strength of stimulus
Refractory Period
Absolute
Relative
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Information Processing and
Making Decisions
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Input
The Human
Output
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Information-Processing Stages
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Stimulus-Identification Stage
•Sensing environmental information
•Exteroceptors
•Proprioceptors
•Representation of stimulus and its nature
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Response-Selection Stage
•Translation from perception to a
response in the form of a motor program
MP
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Response-Programming Stage
•Organizing the selected movement
•Retrieve motor program
•Command correct muscles
•Choose appropriate force
•Choose appropriate timing, etc.
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Feedback in Movement
Control
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
As we execute movements, the
receptors in our bodies continually
update the CNS about the nature of our
actions

The efficiency of motor control by the
information-processing system depends
on feedback
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Central
Processing
System
Functions
Sensory
Receptors
•Ears
•Eyes
•Proprioceptors
Coaching
Instructions
•Watch the
opponent
•Feel the ball
•Keep
balanced
•Listen to
teammates
•Vestibular
system
•Etc.
•Perception
•Decision
making
Effector
System
•Data storage
and coding
•Biceps
•Transition to
motor program
•Abdominals
Exteroceptive
Feedback
•Quadriceps
•Latissimus
dorsi
Output
•Pivot
•Dribble
•Jump
•Error
information
•Shot
•Pass
•Motivate
•Reinforce
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Closed-Loop Control
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
Follows the idea that movements may be
planned and adjusted by feedback even
during a movement

This general closed-loop control process is
self-regulating and will continue to maintain
the desired movement of the performer

Key elements:
– Feedback
– Error detection
– Error correction

Analogy: thermostat
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Input
Error
Senses
CNS
Executive
The stages of
information
processing
PNS
Effector
The motor
program and
motor system
Perception Comparator
Stimulus
(Reference
Identification system)
Correction
Response Selection
and Programming
Response
Execution
Motor
Program
Proprioceptive Feedback
Muscles
Exteroceptive Feedback
Output
Environment
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Advantages of the Closed-Loop System
New skills
 Activities requiring
precision and accuracy
 Allows adjustment
according to the situation
 Adds versatility to
movements

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Disadvantages of the Closed-Loop
System

Rapid, discrete actions do not
properly fall under closed-loop
control

Demands attention and time
– Feedback must pass through the
processing stage
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Open-Loop Control
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
Describes control of automatic actions

Motor program defines the details of skilled
action before the movement begins and
without the influence of peripheral feedback

Movements may be structured in advance,
enabling them to run off automatically when
initiated

Two main components:
– The executive
– The effector
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STIMULUS
EXECUTIVE
•Chooses motor
program
•Relays instruction
EFFECTOR
•Carries out specific
instructions
automatically
No Feedback
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Advantages of the Open-Loop System

Fast and forceful
movements can be
produced without
extensive conscious
control

Attention can de diverted
to other responses

Does not demand as
much time because there
is no feedback
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Disadvantages of the Open-Loop System

Not as effective in unstable and less
predictable situations
– Movements may not be determined
effectively in advance

Not effective in precise and complex
actions
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Factors Affecting Information
Processing
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Sensory
Receptors
Relay
Sensory Input
Quality
Arousal and
Psychological
Readiness
Information
Processing
Capacity to
Concentrate
Reaction
Time
Ability to
Anticipate
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