Chapter 3 Flashcards
a
Objectives:
neuromuscular system
Conceptual model
Motor performance
Principle of visual control and how to relates to movement
Closed-loop control
How sensory info is used
Roles of vision in movement
how sensory contributes to the conceptual model
Exteroceptive Information
Info from the environment
From outside the body
6th Sense / Proprioception
Sense of movement and state of the body
info through proprioceptors
Kinesthesis–
Conscious awareness of the body
Difference btw proprioceptors vs Kinesthesis
movement
awareness of the body
Muscle Spindles: Intrafusal Fibers
What type of muscle?
What information does it send?
Type: Skeletal Muscle
Muscle length and rate of stretch to CNS
Simulates reflexive contraction
Golgi Tendon Organs
Where are they located?
What are its functions?
Located btw muscle and tendon
Provides info about muscle force
Simulates reflexive muscular relaxation—Inhibit the force
Cutaneous Receptors
Located?
What are the functions?
Receptors of the skin
Detects pressure, temperature, touch etc.
Closed Loop Control
Functions
Adjustments to fix a task
slow, continuous movements
Using feedback to correct
Components of closed-loop control:
1. Comparator
2. Executive
3. Effector
4.Feedback
Comarator—Error Detection
Executive—”Brains” Determines actions to fix the ideal state
Effector—Carries out decisions.
Feedback—Provides info on the current state.
Closed-loop: Executive
Information processing
—Stimulus identification—Response selection—Response programming
Feet forward
What action do I need to take to fix error?
Closed Loop: Effector
Motor program nerves/Muscles.
Tells which muscles to contract and how to do it.
Closed Loop: Comparator
Since closed-loop systems are relatively slow, how do we conduct quick actions effectively?
Reflexive Modulations
Quick corrections
Open Control
Pre-packaged motor programs
Only makes corrections in the effector system.
Happens automatically.
Reflexive Modulations
- Reflexes can automatically adjust muscle force in response to sudden demands
- Quick corrections
- Happens in the effector stage
- automatic—Non-concious
Reflexive Modulations//Types of Compensations.
M-reposnes
What are latencies?
M-Responses—Relatively low-level, fast modultaions
Time=Latencies
M1 = 30-50ms
Muscle info
M2 = 50-80ms
Brain info/inital response
Triggered reaction 80-120ms
M3 = Rt (Reaction time response) 120-180ms
Intentionally responding
Types of Compensations: M1
how many synapse? Concious or unconcious? Characteristics?
30-50ms monosynaptic
stretchreflex; muscle spindle response to initial muscle stretch
only one synapse between muscle and spinal cord
Charcateristics:
* Fast
**Postural reflexes
Operates in Parallel *
unconscious,inflexible,littleenvironmental impact
Types of Compensations: M2
how many synapse? Concious or unconcious? Characteristics?
Functional stretch reflex—50-80 ms
Polysenaptic
“knee jerk” reflex
( higher EMG activity than M1 reflex
connections to cerebellum and motor cortex)
Characteristics
* unaffected by increasing number of S-R alternatives
* can be “tuned” beforehand – strong response or weak response
Types of Compensations: Triggered Reaction
Triggered response–Catch a wine glass // touch hot stove
* 80-120ms— Too fast to be voluntary
Series of movements——affects muscles related to, but not necessarily directly involved in, the movement
cutaneousreceptors
Types of Compensations: M3
Also called?
Voluntary Reaction Time ——120-180ms
Powerful and sustained
Modified by:
* Instructions
* Anticipation
* Number of S-R alternatives
Which of the stages of compesnastion are the actual response?
M3—Trigggered
The shorter the latencey the more ____ the moevment
the more flexibility is desired, more information needs to be processed and more —— is required
rigid; Time
What Dictates degree of Flexability of a movement?
Time
Is there always time for all M movements?
No
Boxing Jab—40 ms
which M reponses?
no time for M2 response or involvement of the comparator … therefore, can’t modify the punch once it has been started
Baseball swing—100 ms
which M reponses?
M1 response is fast enough to influence the swing … M2 response doesn’t have time to get to the muscles … information from the comparator cannot get to the executive in time
tennis serve - 300 ms
which M reponses?
enough time for outer loop information to get back to the muscles, therefore the movement can be controlled by a closed-loop system
anytime you can make an adjustment you are using closed loop control
why do we pay attention to focal vison?
Visual dominance.
domainatnt system
What is vidual capture?
How can it be bad?
too much focus on focal vision
because of time requirements to process focal information
What are your two visual systems?
Focal Vision
Ambient Vision
What does Focal Vision do?
What part of brain?
Identifies objects, in center of visual field
effected by light
occipatal
What is concious Vison? fast or slow?
(part of focal vision)
Whatever you direct your attention to, primarily in the center of the visual field
we see, decide what to do and then decide how to do it
Contributes to perception of objects
answers what is it
can’t use it if you’re trying to act quickly (200ms)
Ambient Vision
Detects or ientation of body in environment; specialized for movement control
PERIPHERAL and CENTRAL (WHOLE VISUAL FEILD)
Non-conscious—not effected by light
Places us in the environmnet
Works in the background
Dorsal lobe
Focal Vision
1. Visual Field location
2. Awareness
3. Effect of low illuminatoin
4. Gerneral question resolved
