L7A: Sensory Contribution I Flashcards
What Two primary sources produce
sensory feedback?
Exteroception
Proprioception
What is Exteroception?
Exteroception (External environment)
- Information about movement (you or objects) in the environment.
- Primarily vision, also audition (hearing), olfaction (smell)
What is Proprioception?
Proprioception (Within the body/internal)
- Information about our own movements
Eg*: length of muscles (muscle spindles), forces produced by muscles (golgi tendon organs/GTOs), orientation of head in space (vestibular apparatus)
What are the 2 Methods to Control Movement?
The Control of movement has been conceptualized
as ranging from Open-loop to Closed-loop
What is Open-loop control?
Movement is planned/programmed fully in advance and does not rely on feedback for successful execution
When is Open Loop Control beneficial?
This type of system is useful in Predictable environments when the movement is Short
Simple schematic of Open-loop control
What is Closed-loop control?
Online/moment-to-moment control of movement -
Involving constant processing of feedback
When is Closed Loop control beneficial?
This type of control system is useful when the environment is Unpredictable and the body needs to control itself for Longer periods of time
What is the primary difference between open and closed control loops?
O: Feedback is NOT necessary to achieve a desired goal
C: Feedback IS necessary to achieve a desired goal
Closed-loop control: Continuous
processing of feedback for action success
What process is this? How could we change it?
What are the Four key
closed-loop components?
- Executive
- Effector(s)
- Comparator
- Error Signal
closed-loop components
What is the Executive?
determines the actions to be taken to achieve the desired goal state (‘decisions’)
closed-loop components
What is the Effector?
carries out the desired action
closed-loop components
What is a Comparator?
compares the desired movement (reference) with the actual movement
closed-loop components
What is an Error Signal?
difference between the desired movement (reference) and the actual movement
Information acted on by the executive
What are the component of Open Loop Control Systems?
All closed-loop control systems have these 4 components
Open-loop control systems only have these first 2
Executive & Effector
Closed Loop Control of a Mechanical System
Example: Central Air Conditioning
Examples of open- and closed-loop
systems in sports & everyday actions
What 3 main factors affect whether CNS will act in a more open vs. closed-loop fashion?
- Time: How long will the action take?
- Precision: How much tolerance is there for error?
- Predictability: How constant/ familiar is the environment?
How does Time affect which
system will be used?
Time: How long will the action take to be completed?
- Closed-loop, longer, more continuous (swimming)
- Open-loop, shorter, ballistic, discrete (boxing)
How does Precision affect which
system will be used?
- Closed-loop, Fine / precise (sewing)
- Open-loop, Gross, less precise
How does Predictability affect which
system will be used?
Closed-loop:
- open skills, new skills (low in predictability)
- dribbling a basketball in game
Open-loop:
- closed skills, well practiced (predictable)
- Baseball Pitch
For conscious closed-loop control, all stages of
info. processing represent the _____________
For conscious closed-loop control, all stages of info. processing represent the executive
How long does this Process take?
SO SLOW PROCESS.
Subject to RT Delays (min of 100-150 ms)…
ReIdentify, Re-Select & Reprogram
