Chapter 4

1. Chapter 4 Neural Mechanisms Contributions and Control

2. The Nervous System—Central Nervous System (CNS) • Brain and spinal cord • Processes: • Sensory information is integrated • Decisions are made • Signals are generated and sent to muscles and glands to carry out responses

3. The Nervous System—Peripheral Nervous System (PNS) • Nerves that extend from brain and spinal cord, linking body and CNS • Afferent division: • Detects changes in the environment and conducts nerve impulses from sensory receptors to CNS • Efferent division: • Transmits nerve impulses away from the CNS

4. Sensory Receptors • Exteroceptors: • Detect stimuli outside the body • Provide information about the external environment • Interoceptors: • Detect stimuli from internal viscera • Provide information about the internal environment • Proprioceptors: • Provide information regarding body position and movement • Detect changes in muscle tension, joint position, and equilibrium

5. Vision • Predominant sensory receptor: • 70% of all the body’s sensory receptors are located in the eyes • 40% of the cerebral cortex is thought to be involved in some aspect of processing visual information • Sport vision: • Focuses on investigating visual contributions to performance

6. Basic Structures of the Eye

7. Visual Fields of the Eyesand Associated Neural Pathways

8. Focal vs. Ambient Vision • Focal system: • Functions to identify objects located primarily in the center of the visual field • Linked to consciousness • Operates under voluntary control • Ambient system: • Thought to be responsible for spatial localization and orientation • Functions at a subconscious level • Serves both central and peripheral visual fields

9. Your Perspective • When you are out walking or bike riding in the woods, what do you pay attention to and what other things are you just vaguely aware of? • How does this differ when you are walking down a city street at night?

10. Visual Abilities in Performance • Eye dominance • Spotting • Fixating • Visual search

11. Eye Dominance • One eye processes information and transmits it to the brain more quickly than the other • Same-side dominant • Cross-dominant

12. Visual Search Strategies • Quiet eye • Targeting skills: • Archery, rifle shooting, putting, free throws in basketball, etc. • Interceptive skills: • Striking, catching, landing, avoiding a collision • Tactical skills: • Quick, accurate situational decision making • Attention to relevant environmental cues • Pattern recognition

13. VisionTips for Practitioners Develop effective visual search strategies: • Instruction and feedback should direct learners to areas where critical cues occur • Appropriate learning experiences should provide extensive practice opportunities • Video training—with challenges to anticipate an opponent’s actions • Context of learning situations should include a good deal of variability

14. Proprioception • The continuous flow of sensory information received from receptors in muscles, tendons, joints, and inner ear regarding movement and body position. • Types: • Golgi tendon organs • Muscle spindles • Joint kinesthetic receptors • Vestibular apparatus

15. Proprioception and Performance • Makes the motor control system more efficient and flexible • Provides information about initial body and limb position, which serves as the basis of programming of motor commands • Evaluates movement for correctness: • Compares proprioceptive feedback to the intended goal • Makes adjustments

16. Transmission of Information via the Spinal Cord

17. Sensory and Motor Pathways • Sensory (ascending) pathways: • Spinothalamic and posterior or dorsal column pathway • Conduct impulses related to pain, temperature, touch, pressure, and vibrations • Motor (descending) pathways: • Pyramidal and extrapyramidal pathways • Conduct impulses related to voluntary and subconscious movements

18. Spinal Reflexes • An automatic, involuntary response to stimuli • Reflex arc—simplest pathway by which a reflex occurs • Types: • Monosynaptic reflex • Polysynaptic reflex

19. Reflexes Monosynaptic reflex loop Withdrawal and crossed extensor reflex arc

20. Damage to the Spinal Cord • Types of injury: • Complete • Incomplete: Effects depend on the area of the spinal cord affected • Level of injury: • In general, the higher up the spinal cord that injury occurs, the greater the extent of the injury.

21. Parts of the Brain • Brain stem • Diencephalon • Cerebrum • Cerebellum

22. Areas of the Cerebral Cortex • Sensory areas • Motor areas • Association areas • Basal ganglia

23. Functional Areas of the Cerebral Cortex

24. Cerebellum • Monitors movement by comparing what was intended with what is actually taking place • Plays a key role in detecting and correcting errors • Works with motor cortex to produce smooth, coordinated movements • Plays a key role in maintaining posture and balance

25. Memory Systems

26. Subsystems of Long-Term Memory • Episodic memory: • Information about personal experiences and events • Semantic memory: • General, factual knowledge • Procedural memory: • Skills, operations, and actions

27. Your Perspective • Sometimes it is much easier to remember events from our childhood than to remember what we had for breakfast the day before yesterday. Why do you think that is? • Why do you think certain smells or songs have such a strong effect on our ability to remember people and events?

28. Forgetting • Decay theory • Interference theory: • Proactive interference • Retroactive interference

29. Proactive and Retroactive Interference

30. MemoryTips for Practitioners • Keep instructions and feedback short and simple • Provide ample opportunities for physical rehearsal • Relate a skill being learned to previously learned skills • Use meaningful labels and analogies to strengthen associations • Group several movements together