MC 1 (foundations, feedback and movement control)

Question 1

What is a motor behaviour?

Answer 1

a motor activity (action) carried out through muscle contraction

Question 2

What is a motor task?

Answer 2

the objective to be achieved through a motor behaviour

Question 3

What’s the difference between an action and a movement?

Answer 3

action = aim
movement = way of achieving aim

Question 4

What is motor equivalence?

Answer 4

the same action carried out by execution of different (sequences of) movements

e.g. different ways to pick up a bag

Question 5

What is motor adaptability?

Answer 5

the ability to accomplish the same motor task by adjusting the motor behaviour to different conditions

Question 6

What is motor control?

Answer 6

the ability to maintain and change posture and movement in a variety of contexts

Question 7

What’s the difference between an open and closed loop system?

Answer 7

open loop doesn’t monitor the environment, closed loop does.
closed loop is therefore able to alter the input based on the output

Question 8

What is feedback control?

Answer 8

correction based on the difference between the observed and desired measure

Question 9

How does the proportional feedback control law differ from feedback control?

Answer 9

the control variable is proportional to the error

Question 10

What are the two branches of the NERVOUS SYSTEM and their components?

Answer 10

CNS: brain + spinal cord (all contain grey and white matter)
-protected by bones

PNS: nerves (axons) and ganglia (neurons)
- not protected by bones

Question 11

Two main components of the Cerebrum?

Answer 11

> cerebral cortex

> basal ganglia

Question 12

What are the 4 lobes of the cerebral cortex and their functions?

Answer 12

> frontal
temporal
parietal
occipital

sub-division isn’t functional but each lobe receives input from different sensory systems and is involved in different types of processes

Question 13

Where is the motor cortex and what are its functions?

Answer 13

an area in the frontal lobe of the cerebral cortex.

fundamental for voluntary motor control and the planning/deciding of actions

Question 14

What are the 3 sub-divisions of the motor cortex?

Answer 14

> PRE-MOTOR CORTEX: organisation of movements before initiation
PRIMARY MOTOR CORTEX: initiation and coordination of voluntary movements
SUPPLEMENTARY MOTOR AREA: prep and control of sequential movements

Question 15

The role of the basal ganglia?

Answer 15

controlling voluntary movement

Question 16

What makes up the basal ganglia?

Answer 16

set of subcortical neural nuclei

• striatum (caudate nucleus + putamen)
• globus pallidus
• substantia nigra
• subthalamic nucleus

Question 17

Give a short overview of the direct pathway through the basal ganglia and the output the the thalamus and cerebral cortex

Answer 17

substantia nigra
                (stimulates)
putamen 
                  (inhibits)
globus pallidus int
                  (less inhibition of)
thalamus
                (more stimulation of)
cerebral cortex

Question 18

What is the resultant effect of the direct pathway on the cerebral cortex activity?

Answer 18

Activation of cerebral cortex

more movement

Question 19

Give a short overview of the indirect pathway through the basal ganglia and the output the the thalamus and cerebral cortex

Answer 19

substantia nigra
                  (inhibits)
putamen 
                 (less inhibition of)
globus pallidus ext
                 (less inhibition of)
subthalamic nucleus
                (more excitation of)
globus pallidus int
                (more inhibition of)
thalamus
                (less stimulation of)
cerebral cortex

Question 20

What is the resultant effect of the indirect pathway on the cerebral cortex activity?

Answer 20

Inhibits cerebral cortex

less movement

Question 21

What is Parkinson’s disease?

Answer 21

death of neurons in the substantia nigra

Question 22

What effect does Parkinson’s have on the cerebral cortex and movement?

Answer 22

Reduced cerebral cortex activation.

• difficulty initiating movement
• slowness of voluntary contractions
• shuffling gait
• tremor at rest

Question 23

What is Huntington’s disease?

Answer 23

lessions in the subthalamic nucleus

Question 24

What effect does Huntington’s have on the cerebral cortex and movement?

Answer 24

increased cerebral cortex activation.

- excess of involuntary movement

Question 25

Where is the cerebellum located and what is its role?

Answer 25

located at the back of the pons (brainstem)
- fundamental role in execution 
  of smooth and accurate 
  movement
- concerned w/ motor 
  coordination, posture and 
  balance

Question 26

How is the cerebellum involved in the correction of movement?

Answer 26

it receives input from the motor cortex (movement plan) and sensory systems (movement performance) and compares in order to correct and adjust movements

Question 27

Aim of the direct pathway?

Answer 27

‘loosen the leash on the thalamus’

Greater activity of thalamus, and in turn, cerebral cortex.

Question 28

Aim of the indirect pathway?

Answer 28

‘tighten the leash on the thalamus’
less activity of thalamus, and in turn, cerebral cortex

Think of changing from running to walking.