Lecture 20 - Principles of motor control

Question 1

what are marr’s 3 levels of analysis of the brain?

Answer 1

implementational (what is system made from), algorithmic (what does system do), computational (what problem does it solve)

Question 2

which one of marr’s 3 levels of analysis does the motor system carry out?

Answer 2

computational

Question 3

give an example of simple feedback (servo) control and what happens to the feedback control in the example

Answer 3

multi joint movements e.g picking up object to your right with your left arm (as you get closer to object target on right, feedback control decreases)

Question 4

feedback control with time delays is either…..

Answer 4

very slow or unstable

Question 5

the motor system uses knowledge about the body and environment to make fast feedforwards movements even when feedback is slow, this is known as an……. model mapping consequence to …….

Answer 5

internal /inverse, cause

Question 6

what does the forward model predict? what can it distinguish between?

Answer 6

sensory consequences of actions, can distinguish between self-generated and external sensory feedback - can’t tickle yourself

Question 7

in signal dependent noise in force production, the higher the muscle force being generated, the higher the …….

Answer 7

inaccuracy

Question 8

to calculate the inaccuracy of force hen 2 agonist muscles are used, what would you do?

Answer 8

add the inaccuracies

Question 9

give the equation for signal dependent noise

Answer 9

sigma (variance) = k x F (force)

Question 10

describe the uncontrolled manifold hypothesis

Answer 10

skilled movements are characterised by repetition without repetition - slightly different movements achieve the same goal

Question 11

what is the name of the best current model of how the brain controls complex, skillful movement?

Answer 11

optimal feedback control theory