College 7: Motor skills

Question 1

What 2 types of movements belong to automated movements?

Answer 1

Postural & Rhytmic movements

Question 2

What is the function of a muscle spindle?

Answer 2

Respond to the stretch of a muscle -> providing information from the muscle to the brain

Question 3

What is the function of a Golgi tendon organ?

Answer 3

Control the intensity/strength of a muscle -> provinding information from the muscle to the brain

Question 4

What 2 types of neurons are lower motor neurons?

And what is their function?

Answer 4

1. Alpha motor neuron = cause contractions of the skeletal muscles
2. Gamma motor neuron = adjust the tension in the muscle spindle fibers so they can detect a stretch

Question 5

What is the spinal motor circuit of a reflex?

Answer 5

Sensory signal via dorsal root in the spinal cord -> crossing interneuron -> to muscle via ventral root = to trigger a counterbalancing contraction to counteract the stretch of the reflex

Question 6

What are central pattern generators?

Answer 6

The neurons in the spinal cord, they influence rhytmic behaviors like walking

Question 7

How does the corticospinal tract travel?

Answer 7

M1 -> corona radiata -> internal capsule -> cerebral peduncle -> crossing over at medulla -> pyramidal decussation -> spinal cord

Question 8

What do influence/coordinate these non-corticospinal motor control pathways?

1. Rubrospinal tract
2. Vestibulospinal tract
3. Tectospinal tract
4. Reticulospinal tract

Answer 8

1. Rubrospinal tract = influences the limbs
2. Vestibulospinal tract = influences balance
3. Tectospinal tract = coordinates movements in order to capture/avoid targets
4. Reticulospinal tract = coordinates startle and escape reflexes

Question 9

What areas are mostly involved in motor control? (4x)

Answer 9

Primary motor cortex (M1)
Premotor cortex (PMC)
Supplementary motor cortex
Presupplementary motor cortex

Question 10

What is population coding?

Answer 10

A population of neurons will fire at higher rates when the direction is closer to their preferred direction

Question 11

Where are mirror neurons found?

Answer 11

In the PMC, connecting regions of the superior temporal sulcus

Question 12

What are the following areas responsible for?

1. M1
2. PMC
3. Lateral prefronal cortex
4. Frontopolar cortex

Answer 12

1. M1 = simple movements
2. PMC = complex actions
3. Lateral prefronal cortex = cognitive and planning contributions
4. Frontopolar cortex = higher-order learning goals (long-term/multi-tasking)

Question 13

Which system controls movements guided by external cues?

Answer 13

Lateral motor system

Question 14

Which system becomes active when internal signals are needed?

Answer 14

Medial motor system

Question 15

What is akinetic mutism?

And what can cause this?

Answer 15

No spontaneous behavior seems to occur anymore

Caused by lesions in the medial motor system (can also cause the opposite: over-automatically behavior)

Question 16

Of what 3 layers does the cerebellum consists?

Answer 16

Granule layer
Purkinje layer
Molecular layer (outer layer)

Question 17

What is forward modeling?

Answer 17

Combining sensory and motor information to predict where an object will be at some future point in time (for smooth coordination of the cerebellum)

Question 18

What are the following recursive loop circuits responsible for?

1. Oculomotor loop
2. Orbitofrontal loop

Answer 18

1. Oculomotor loop = eye movements

2. Orbitofrontal loop = evaluation of reward

Question 19

What definition is ‘knowing the location of your body in space’?

Answer 19

Proprioception

Question 20

What is manual dexterity?

Answer 20

The ability to use your hands in a killfull/coordinated way

Question 21

What is locomotion?

Answer 21

The ability to move from one place to another

Question 22

What is motor skill acquisition?

Answer 22

Practice/experience leading to a relatively permanent change in an individual’s capability for skilled motor performance

Question 23

What 3 phases does motor skill acquisition has?

Answer 23

1. Early/cognitive phase = declarative, verbal (self-talk) learning (explicit)
2. Associative phase = detect and eliminate errors, linking components for smoothness
3. Autonomous phase = more automatic performance/skill has developed, without the need for much conscious attention (implicit)

Question 24

What is sequence learning?

Answer 24

The acquisition of new movement patterns via long-term practice -> small actions combined to a sequence of movements

Question 25

What is the neural basis of sequence learning?

Answer 25

The involvement of frontal areas decreases as the skill is developing, while the motor areas increase in involvement

Question 26

What is motor adaptation?

Answer 26

The ability to adjust our movements to changing internal/environmental demands, like goggles that shift the visual field or split-belt traitmills

Question 27

What happens with Parkinson’s disease?

Answer 27

Loss of dopamine in substantia nigra -> the indirect inhibitory pathway becomes more active -> this decreases excitation to the thalamus and cortex

Leads to understimulation of movements

Question 28

What happens with Huntington’s disease?

Answer 28

Caused by a gene mutation producing a toxic form of Huntintin -> especially toxic to the caudate & putamen -> here the indirect inhibitory pathway is affected ->

Leading to non-voluntary rhytmic movements (chorea) + difficulties with self-control of thoughts/emotions/behavior

Question 29

What is apraxia?

Answer 29

The inability to perfrom purposeful movements/tasks despite intact sensory & motor functions -> so due to deficits in the higher control

Question 30

What is ideation apraxia?

Neuron level?

Answer 30

Having no idea of what to do -> inapproprioate use of objects or difficulty with multi-step tasks.

At neuron level it is mostly associated with diffuse damage troughout the brain

Question 31

What is ideomotor apraxia?

Neuron level?

Answer 31

Intact understanding/verbalization, but loss of access to kinetic memory = difficulty with producing movements on verbal command and to mimic gestures

At neuron level: damage left frontoparietal areas

Question 32

No spontaneous behavior seems to occur anymore

Answer 32

Akinetic mutism