Closed Loop Control

Question 1

What is closed loop control and when

Answer 1

We have time for feedback

Happens after a period of time, not straight away

An ongoing task

Feedback into the loop

Have a reference of correctness

Question 2

Explain the expanded model of closed loop control

Answer 2

Still start with:
- stimulus identification
- response selection
- response programming

Then
- reference of correctness
- from muscles movement and environment
- use for comparison

Compare what actually happened with what we predicted to happen (predict sensory consequences)

If error, feedback into stages of information processing

Question 3

Define feedforwards

Answer 3

The modification or control of a process using its anticipated results or effects

Compare consequences to predicted sensory consequences

Question 4

Explain tickling and feedforward

Answer 4

Dosent work as you predict sensory consequences

Question 5

What is reflexive closed loop control

Answer 5

Dewhurst

Add unexpected weight making arm drop

Natural reaction to return arm to normal position

Question 6

Explain long loop reflex/triggered reaction

Answer 6

EMG

Three responses

M1: monosynaptic stretch reflex - as bicep stretches, muscle fibres and spindle stretch, signal to spinal cord, then back to muscle and it twitches (no stages of processing, closed loop, too quick)

M2: long loop/ triggered reflex
- signal to base of brain
Triggers pre programmed reflex to bring arm back up
(Closed loop, too quick for feedback still)

M3: voluntary

Question 7

What happens if pots told to let the arm drop

Answer 7

Still get M1 response, hard wired - still muscle twitch

Triggered long loop less seen on EMG

No voluntary bit