Lecture 4: Neural Mechanisms (MD) Flashcards

• Responsible for processes that underlie
  • Movement preparation
  • execution
  • controll

• Brain and spinal cord
  • sensory information integration, decision making

• Links the body and the CNS
  • Afferent (sensory) // ARRIVES
  • Efferent (motor) // EXIT

1. Exteroceptors
2. interceptors
3. proprioceptors

• External environment
  • pressure, pain, temperature, VIBRATION, 5 senses

• Internal environment
  • hunger, nausea, fatigue

• Provide information on muscles tension, joint position, equilibrium (inner ear)

70% are in the eyes (most)

• 40% processes visual information
• EX. Being able to see in the dark
• Fovea: directly behind the eyes

1. Light rays enters eye
2. light rays are manipulated + focused on the retina
3. an image is formed + converted into nerve impulses
   1. photoreceptors: light sensitive cells that converts light rays into nerve impulses

1. Rods
2. Cones

• Vision in dim light, enables us to see shapes + movements, and discriminate

• Operates best in BRIGHT LIGHT (in fovea)
• specilize for color vision and vision acuity (sharpness)

• Involves the fovea
• used to focus on objects directly in central region of the visual field
• operatates under voluntary control // EX. Driving to not rear end a car
• ”WHAT IS IT?”
• not good in low light conditions

• Subconsious
• used for spracial localization and orientation (surroundings)
• not effected by light, serves the peripheral and central visual fields

• Information is processed through both systems simultaneously
• EX. Walk around the room and text someone

1. eye dominance
2. spotting
3. visual search
4. quiet eye

• Eye that processes information FASTRER
• Cross-dominant = advantage

• keeps proper orientation
• reduces dizziness
• used in rotational skill
  • EX. dancing, figure-skating

• scan of environment for regularory cues
  • familiarity
  • Ex. where's waldo activity

• final fixation on target before movement
  • EX. watching the hoop rim before a free throw

1. targeting skills
2. interceptive skills
3. tactical skills

• propessling an object towards a target
• specific fixation on target is key

• tracking of stimulus // timing of stimulus // limb movement to intercept stimulus
• time to contact
  • Tau: size of retina image/rate of change of image
• Typically objects are NOT TRACK to CONNECT

• require quick, accurate decision making

1. optic flow
2. feedflow

• perceived relative motion between objects + observers
• allows for discernment of how QUICKLY objects approach / move away

• allows info to be sent AHEAD of movement (for preparation)
• details of terrain, object dimensions, etc.
• used to contact and avoid objects`

1. search strategies
2. pattern recognition
3. anticipation
4. decision-making skills

• instructions => FEEDBACK should direct learners' attention to areas where critical cues occur
  • EX. release point of a pitched ball
• design appropriate learning experiences that provides PRACTICE for task-relevant cues

• d

• video training where oppoennts actions are studied (TAPE)

• w

1. Golgi tendon organs
2. muscle spindles
3. joint kinesthetic receptors
4. vestibular apparatus

• located at junction of tendon (with muscle)
• detects => muscle tension
• protects => form heavy/great load
  • relaxes muscles if load is too great

• located @ muscle fibers in muscle belly
• detects => muscle stretch
• protects => from excessive stretching
• responsible for STRETCH REFLEXES

• located in + around synovial joints
• detects => pressure, acceleration. deceleration strain
• determines if => movements too slow, fast, wrong direction

• group of receptor organs in INNER EAR
• detects => changes in posture + balance
• provides sensory information on EQUILIBRIUM

• makes motor control more efficient + flexible
• Goal = movement effects error detection

• promote development of proper frame of reference
• provide a variety of positions + movements + multiple environments
• stress kinesthetic feedback for optimal learning

• info provided by
  • vetsibular apparatus, touch, proprioception in feet+ankles
• reestablishing proprioception is key in rehab programs

• Compensatory adjustments
  • Movement w/ perturbation or loss of balance
• Anticipatory adjustments
  • voluntary movement to prevent loss of balance

• carries sensory information to the brain, motor information to effectors
• ascending pathways
• descending pathways

• spinothalamic
  • pain, temperature, crude touch, deep pressure
• dorsal column
  • proprioception, discriminative touch, light pressure, vibrations

• pyramidal
  • skilled VOLUNTARY movements
• extrapyramidal
  • SUBCONSCIOUS movements

1. reflex arc
2. monosynaptic reflex
3. polysynaptic reflex

• receptor,
  • sensory neauron,
    • integration center,
      • motor neuron,
        • effector

• 1 synapse => 1 motor neuron
• stretch reflex
• very fast b/c 1 synapse connection

• multiple synapses
  • sensory => interneurons =. motor neuron
• slower = multiple synapses

1. brainstem
2. diencephalon
3. cerebrum
4. cerebellum

• reflex and relay center

• most motor functions
• 2 hemispheres = control opposite sides of body
• higher brain functions

• receives input from proprioceptors + visual receptors
• detecting/correcting errors
• coordination center
• maintains posture + balance

1. sensory areas
2. motor areas
3. association areas

• Primary: cutaneous receptors, proprioceptors
• Secondary: integrates + interprets signals

• coordinate, initiate voluntary movement
• Primary motor cortex: precise muscle control
• Premotor cortex: organizes learned coordinated movements (w/ complex muscle sequencing)

• Prefrontal cortex: emotional + cognitive function, judgements, planning, motivation

• can only hole 7+- 2 information at once
• info gathered for only 20-30seconds
• active processing = longer to transfer to long-term memory

• Procedural: how to perform skills, actions
  • Ex. Riding a bike
• Declarative: facts or events
  • Episodic: personal experiences associated with time (Ex. year you graduated HS)
  • Semantic: general knowledge, conceptual knowledge (Ex. how to know what motor is)

• forgetting = over time memory disappears

• old skills=> can retain new memory skills
• new memory => can't remember old skills

• Keep instructions, verbal cues, feedback short and simple
• Repeat key learning points
• Provide ample opportunities for physical rehearsal
• Relate skill being learned to previous skills
• Use meaningful verbal labels and analogies to strengthen associations
• “Chunk” several moments together