Information Processing in Motor Learning Chapter 17 Sport Books Publisher
Outline Structure and function of the nervous system Information processing and making decisions Feedback in movement control Factors affecting information processing Sport Books Publisher
Structure and Function of the Nervous System Sport Books Publisher
Connects CNS with the rest of the body Control center PNS Connects CNS with the rest of the body Sport Books Publisher
The Neuron and Its Function Sport Books Publisher
Neuron Nerve cell The fundamental functional and structural unit of the nervous system Allows information to travel throughout the body to various destinations Sport Books Publisher
Axon: transmits message to terminal ending Receptive Segment Cell Body Dendrites: receive message Myelin sheath Conductive Segment Axon: transmits message to terminal ending Nodes of Ranvier Terminal ending on muscle: sends off message to adjacent neuron Transmissive Segment Motor end plate Sport Books Publisher
Skipping of the impulse allowing faster conduction Myelin sheath: fatty covering or insulator Skipping of the impulse allowing faster conduction Sport Books Publisher
Types of Neurons Afferent neurons Interneurons Efferent 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 Sport Books Publisher
Types of Neurons cont. Sport Books Publisher
The Neuron’s Function 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) Transmissive segment (axon terminals) Converts electrical nerve impulse to chemical form (neurotransmitter) and sends it off to synapse Conductive Transmissive Sport Books Publisher
Stimulus: depolarization 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 Stimulus: depolarization Rest: polarization Membrane potential = -70 mV (mV) +50 -50 -100 Action Potential +40 mV Resting Potential Stimulus Sport Books Publisher
The Synapse and Synaptic Transmission . : :.. …. …… …..:: : . : .:.;. . . SYNAPTIC TRANSMISSION O O O O Differ in terms of : Neurotransmitter used (e.g., acetylcholine or Ach) General function (e.g., inhibitory vs.excitatory) NEUROTRANSMITTER Sport Books Publisher
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 Sport Books Publisher
Indication of Strength of stimulus Refractory Period Absolute Relative Sport Books Publisher
Information Processing and Making Decisions Sport Books Publisher
Input The Human Output Sport Books Publisher
Information-Processing Stages Sport Books Publisher
Stimulus-Identification Stage Sensing environmental information Exteroceptors Proprioceptors Representation of stimulus and its nature PERCEPTION SENSATION Sport Books Publisher
Response-Selection Stage Translation from perception to a response in the form of a motor program MP 13498 MP 00333 MP 04567 MP 09564 Sport Books Publisher
Response-Programming Stage Organizing the selected movement Retrieve motor program Command correct muscles Choose appropriate force Choose appropriate timing, etc. Efferent nerves Sport Books Publisher
Feedback in Movement Control Sport Books Publisher
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 Sport Books Publisher
Central Processing System Functions Perception Decision making Data storage and coding Transition to motor program Sensory Receptors Ears Eyes Proprioceptors Vestibular system Etc. Effector System Biceps Quadriceps Abdominals Latissimus dorsi Output Pivot Dribble Jump Shot Pass Coaching Instructions Watch the opponent Feel the ball Keep balanced Listen to teammates Exteroceptive Feedback Error information Motivate Reinforce Sport Books Publisher
Closed-Loop Control Sport Books Publisher
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 Sport Books Publisher
Response Execution Motor Program Muscles Output Environment Error Input Senses Correction Perception Stimulus Identification Comparator (Reference system) CNS Executive The stages of information processing Response Selection and Programming Response Execution PNS Effector The motor program and motor system Motor Program Proprioceptive Feedback Muscles Output Environment Exteroceptive Feedback Sport Books Publisher
Advantages of the Closed-Loop System New skills Activities requiring precision and accuracy Allows adjustment according to the situation Adds versatility to movements Sport Books Publisher
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 Sport Books Publisher
Open-Loop Control Sport Books Publisher
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 Sport Books Publisher
EXECUTIVE EFFECTOR No Feedback Chooses motor program STIMULUS EXECUTIVE EFFECTOR Chooses motor program Relays instruction Carries out specific instructions automatically No Feedback Sport Books Publisher
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 Sport Books Publisher
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 Sport Books Publisher
Factors Affecting Information Processing Sport Books Publisher
Information Processing Sensory Receptors Relay Sensory Input Quality Arousal and Psychological Readiness Information Processing Reaction Time Capacity to Concentrate Ability to Anticipate Sport Books Publisher