Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

2nd Year: Brain and Behaviour > Interacting with the world > Flashcards

Interacting with the world Flashcards

You may prefer our related Brainscape-certified flashcards:
The Brain flashcards
1
Q

Movements below the neck are executed by neurons whose cell bodies originate in the brainstem. True or false?

A

False - Movements below the neck are executed by neurons whose cell bodies are in the spinal cord.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Movements of the head and face are executed by neurons whose cell bodies originate in the brainstem. True or false?

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Both reflexes and rhythmic movements such as walking are generally controlled by simple circuits in the spine and brainstem. They require little/no input from the brain. True or false?

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What controls voluntary movements?

A

Motor areas in the cerebral cortex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The motor area of the cortex is divided into 2 sections. What are they?

A
  1. The primary motor cortex

2. The premotor cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is another name for the primary motor cortex?

A

M1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is another name for the premotor cortex?

A

The supplementary motor cortex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Both the primary and premotor cortices send signals to the brainstem and spinal cord. True or false?

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In the primary motor cortex, what do medial pathways control?

A

Posture, particularly when more precise movements need to be executed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Give 3 examples of M1 medial pathways.

A
  1. Reticulospinal
  2. Tectospinal
  3. Vestibulospinal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

In the primary motor cortex, what do lateral pathways control?

A

Precise, goal-directed movements of the distal limbs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Give 2 examples of M1 lateral pathways.

A
  1. Rubrospinal

2. Corticospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where does the rubrospinal pathway emerge from?

A

The brainstem.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the corticobulbar pathway control?

A

Movements of the head and face.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do the cerebellum and basal ganglia help to smooth movement?

A

They send outputs via the thalamus to the motor cortex and brainstem.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why is it that fast movements are not as smooth as slow ones?

A

There is not enough time for effective cerebellar feedback.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a motor map?

A

Much like the sensory map in the somatosensory cortex, in the motor cortex there is an ordered arrangement of neurons that reflect parts of the body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where is the motor map?

A

The precentral gyrus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How was evidence found for the motor map?

A

Stimulation via electrodes in the brains of humans and other primates found that movement was produced in contralateral limbs (those on the opposite side of the body).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why is movement affected by a stroke?

A

Because stroke can cause hypoxia and thus death of cells in various places in the motor map, meaning the patient can no longer move those regions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In the motor map, each region of the body has an equal area of brain space, unlike the SS cortex. True or false?

A

False - the motor cortex also gives a distorted representation of the body. Regions of the body that are involved in more complex, precise movement have more area in the motor cortex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Give examples of 3 body areas that would be overrepresented in the motor map.

A
  1. Face
  2. Hands
  3. Tongue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What was the earliest, simple idea of motor control?

A

Each small part of the motor cortex controlled a single muscle.

24
Q

In actuality motor activity is controlled by a) convergence and b) divergence. What do these terms mean?

A

a) Most muscles are controlled by several parts of the motor cortex
b) Most parts of the motor cortex exert control over several muscles

Essentially the same thing but backwards…‘done psychology (y)

25
Q

The signal that from the motor cortex to the brainstem and spinal cord encodes force. What does this mean?

A

That the signal encodes the direction and amplitude needed to produce a movement, not the actual displacement of a joint.

26
Q

What effect does increasing the firing rate of a motor cortical neuron have on movement?

A

It increases the amount of force exerted by a muscle.

27
Q

Thus what kind of relationship is there between motor cortical neuronal activity and force?

A

Linear.

28
Q

What is population code?

A

Movements are not encoded by individual neurons. Instead they are created by the distribution of activity over a population of neurons. Each neuron ‘votes’ for a movement in a particular direction, and the outcome is the tally of those votes.

Basically the movement goes in whichever direction the majority of neurons code for.

29
Q

What is a neuron’s ‘vote’?

A

A vector with a particular angle.

30
Q

What determines the length of each vector?

A

The number of APs that neuron fires.

31
Q

What happens if all the vectors in a population of neurons are active?

A

They cancel out and there is no movement.

32
Q

What happens if only some vectors in a population of neurons are active?

A

The resultant vector has a direction and length (distance). This can be used to predict movement.

33
Q

How has the principle of population code been used in biotechnology?

A

In the creation of brain-machine interfaces to help paralysed patients or amputees control computer interactions.

34
Q

Where does the primary motor cortex receive input from? List 3 brain areas.

A
  1. Premotor cortex
  2. Somatosensory cortex
  3. Parietal cortex
35
Q

Where does the premotor cortex receive inputs from? Give 2 brain regions.

A
  1. Parietal cortex

2. Prefrontal cortex

36
Q

What condition is associated with a damaged primary motor cortex? Is this the same in the premotor cortex?

A

Paralysis.

Damage to the premotor cortex causes more complex motor impairments - little is understood.

37
Q

Define the readiness potential.

A

A measure of neuronal activity in the premotor area before a movement is initiated. Essentially a build up of neuronal activity in preparation for movement.

38
Q

Define the SMA and where is it?

A

The ‘supplementary motor area’ in the premotor cortex.

39
Q

In the SMA of monkeys, when were readiness potentials observed? Give 2 examples.

A
  1. After a self-initiated action

2. After an instruction to make/withhold a movement

40
Q

Lesions to the SMA in humans causes what?

A

Alien limb syndrome.

41
Q

Define alien limb syndrome.

A

The patient feels as though their limb does not belong to them and is controlled by an external force.

42
Q

What does the SMA appear to heavily involved in?

A

The acquisition of complex sequences of actions.

43
Q

What do neurons in the parietal cortex do in terms of visuomotor integration?

A

Transform visual sensations into motor action.

44
Q

The AIP is involved in grasping objects. Grasping an object a combination of neurons. What are they and when are they active/inactive?

A
  1. Visual: responsible for sensing the object. These neurons appear to be inactive if a grasp is made in the dark.
  2. Motor: responsible for the motor component. These are inactive when the object is viewed but not grasped.
  3. Visuomotor: active when viewing, grasping or viewing and grasping the object.
45
Q

Are the visuomotor neurons always active? Give an example.

A

No - they are active, or more active, only when viewing a subset of objects that may afford the desired action. In humans the visuomotor neurons display elevated activity when looking at tools, objects that afford actions. This was shown by an increased level of activity in the ventral premotor and parietal cortices.

46
Q

What does the activity of visuomotor neurons tell us about perception and motor control?

A

They are separate areas of cognition, and the parietal and premotor areas are intimately involved.

47
Q

Define apraxia.

A

The impairment of ability to execute complex movements in the absence of pure motor or sensory deficits.

48
Q

What brain areas can apraxia be associated with?

A

Lesions to the parietal or premotor areas. The subject cannot accurately perceive the stimuli and bring about an appropriate motor response.

49
Q

What is the ‘mirror neuron’ theory?

A

Areas of the brain involved in coordinating our own responses are also involved in understanding the responses of others. This explains imitation and empathy.

50
Q

What animal were mirror neurons discovered in?

A

Macaque monkeys.

51
Q

Why is there dispute over this theory?

A

Monkeys do not imitate.

52
Q

What is the more traditional view of coordinating own response/understanding the responses of others?

A

Neurons in the ventral visual cortex ‘understand’ a visual scene, including the people within it. Then a separate area in the dorsal section (including the parietal cortex) facilitates visuomotor coordination of an own response.

53
Q

What is the ventral premotor area F5?

A

A region strongly connected to the parietal cortex, the ventral prefrontal cortex and the SMAs.

54
Q

Where did the evidence for motor neurons in monkeys come from?

A

Neurons in F5 were active when a monkey was reaching out and grasping a food reward. A subset of these neurons were also active when watching an experimenter do the same thing.

55
Q

In experiments with monkeys a) strictly congruent and b) broadly congruent neurons were identified. What does this mean?

A

a) Mirror neurons active when an experimenter did the exact same action.
b) Mirror neurons active when an experimenter did a similar action.

56
Q

When were motor neurons inactive? Give 2 examples.

A
  1. When watching an experimenter perform the same action with no reward, i.e. food
  2. When the object, food, was presented without the accompanying action.
57
Q

Mirror neuron theory is highly contested. It is hypothesised that mirror neuron activity is actually a covert movement, one that is not activated. Why would this be?

A

Because of population code: the overall population activity of neurons is not consistent with the movement, i.e. not enough of them vote to make it.

2nd Year: Brain and Behaviour (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions