Lecture 5 - Open-Loop Vs Closed-Loop Control

Question 1

What is a closed-loop system?

Answer 1

• Movement based on feedback
  • Flexible
  • Adaptable
  • Precise
  • Slow

Question 2

What are 2 sources of sensory information?

Answer 2

• exteroception
• proprioception

Question 3

What is exteroception?

Answer 3

• provides information to the processing system about the state of the environment in which one’s body exists

Question 4

What are the 2 types of exteroception?

Answer 4

• vision
• audition (hearing)

Question 5

What is vision in relation to exteroception?

Answer 5

• Provides information of the physical structure of the environment
• also provides information about the movement of objects in the environment in relations to your own movements; i.e., flight path of a ball while you run to catch it

Question 6

What is audition (hearing) in relation to exteroception?

Answer 6

• involves in hearing the things around you
• Activities depend on well-developed auditory skills

Question 7

What is proprioception?

Answer 7

• provides information about the state of the body itself
• a type of intrinsic feedback, provides sensations of body movement through an environment

Question 8

What are the 5 types of receptors in proprioception?

Answer 8

• vestibular apparatus
• joint receptors
• muscle spindles
• golgi tendon organs
• cutaneous receptors

Question 9

What is vestibular apparatus?

Answer 9

• provides information related to head movement & body orientation in the environment
• detects the heads orientation with respect to gravity
• located in the inner ear

Question 10

What are joint receptors ?

Answer 10

• Provides Information about extreme positions of the joints

Question 11

What are muscle spindles?

Answer 11

• Provide information on the stretch & positioning of the muscles
• oriented in parallel with the muscle fibers
• embedded in the belly of the skeletal muscle

Question 12

What are the Golgi tendon organs?

Answer 12

• Serve to regulate the levels of force produced to the attached muscle
• sensitive to muscle tension

Question 13

What are cutaneous receptors ?

Answer 13

• specialized detectors of pressure, temperature, touch, etc

Question 14

What is a basic closed-loop control system?

Answer 14

• when one inputs a desired state or system goal
• Executive System: Decision making
• Effector System: Carrying out the decisions
• Comparator: Reference of correctness against which feedback is compared to define an error
• Error Signal: Information acted on by the executive

Question 15

What is an open-loop system?

Answer 15

• Movement structured in advance, Movements are quick & powerful, Less efficient for unstable situations
• Advance instructions specify operations to be done, their sequencing, & their timing
• the system executes instruction without modification
• No capability to detect or correct errors, feedback not involved, Most effective in stable, predictable environments

Question 16

What is a reflexive mechanism?

Answer 16

• A reflex is a involuntary, stereotypical movement response to a specific stimulus

Question 17

What are the 3 types of reflexive mechanisms?

Answer 17

• M1 response (monosynaptic)
• M2 (multisynaptic)
• reaction time response

Question 18

What is a M1 (monosynaptic) response?

Answer 18

• a quick & direct reflex that provides direct communication between sensory and motor neurons innervating the muscle
• cannot be modified, 30-50 Ms response time
• i.e., tapping patella with an object

Question 19

What is a M2 (multisynaptic) response?

Answer 19

• Quick, but takes longer then M1
• Have more control
• 50-80 ms response time

Question 20

What is a response time response?

Answer 20

• Voluntary, large role of instruction
• Takes the longest
• 120-180 ms response time