Lecture 8 (motor function and language)

Question 1

What are reflexes?

Answer 1

Simple, unvarying, and unlearned responses to sensory stimuli such as touch, pressure and pain.

Question 2

What are motor plans?

Answer 2

A complex set of commands to muscles that is established before the behavior starts.

Question 3

The hierarchical neural organization of the motor control?

Answer 3

o Skeletal system and muscles
o The spinal cord
o The brainstem
o Primary motor cortex
o Nonprimary motor cortex
o Cerebellum and basal ganglia

Question 4

How does neural message result in muscle movement?

Answer 4

Movements around a joint requires one set of motor neurons to be excited while the antagonistic (the muscles that works opposite) set of motor neurons is inhibited.

Question 5

What does primary motor cortex primarily consist of?

Answer 5

The precentral gyrus, just anterior to the central sulcus.

Question 6

What happens after brain damage in primary motor cortex?

Answer 6

Partial paralysis on the side of the body opposite the brain lesion.

Question 7

In which movements is primary motor cortex used?

Answer 7

Used with body parts involved in the most elaborate and complex movements, for example hand movements.

Question 8

When does motor representations in M1 change?

Answer 8

As a result of training.

Question 9

What is nonprimary motor cortex’s function?

Answer 9

Provide an additional source of motor commands, acting indirectly via primary motor cortex and through direct connections to lower levels of the motor hierarchy such as the brainstem and spinal cord.

Question 10

What is nonprimary motor cortex divided into?

Answer 10

The supplementary motor area (SMA) and premotor cortex.

Question 11

The supplementary motor area (SMA)?

Answer 11

planning movements that are internally generated

Question 12

Premotor cortex?

Answer 12

directs movement in response to external cues.

Question 13

Where is enhanced blood flow seen when people simply mentally rehearse a complex movement sequence?

Answer 13

Only in the SMA, not the primary motor cortex.

Question 14

When are the basal ganglia especially important?

Answer 14

Are especially important in the performance of movements influenced by memories, in contrast to those guided by sensory control.
Also important in skill learning.

Question 15

The basal ganglia?

Answer 15

These structures receive input from wide areas of the cerebral cortex and sends much of its output back to the cortex via the thalamus, forming a loop from the cortex through the basal ganglia and thalamus and back to the cortex.

Question 16

When does the basal ganglia play a role?

Answer 16

when determining the amplitude and direction of movement and the initiation of movement.

Question 17

Why does the basal ganglia work with M1?

Answer 17

to initiate and terminate movements.

Question 18

What is the biggest difference between the pyramidal system and the basal ganglia?

Answer 18

The pyramidal system has a tract through medulla which the basal ganglia doesn’t. This means that pyramidal system innervates directly with the motor neurons which the basal ganglia does indirectly

Question 19

The pyramidal system?

Answer 19

Consists of neuronal cell bodies within the cerebral cortex and their axons, which pass through the brainstem, forming the pyramidal tract to the spinal cord. Is seen most clearly where it passes through the floor of the medulla.
They are responsible for the voluntary control of the musculature of the body and face.
In the medulla the pyramidal tract from the right hemisphere crosses the midline to innervate the left spinal cord, and vice versa.

Question 20

Cerebellum and movement?

Answer 20

It elaborates neural programs for the control of skilled movements, particularly rapid, repeated movements that become automatic.

Question 21

Cerebellum and SMA?

Answer 21

monitor ongoing activity to produce smooth movements.

Question 22

Ataxia?

Answer 22

Loss of coordination. Damage in the uppermost part of the cerebellum.

Question 23

Decomposition of movements come from?

Answer 23

damage to the lowermost part of the cerebellum.

Question 24

What does the uppermost part of the cerebellum normally do?

Answer 24

this part receives sensory information about the current spatial locations of the parts of the body and anticipates subsequent movements.

Question 25

What does the lowermost part of the cerebellum normally do?

Answer 25

it is implicated in planning complex movements, so damage here can cause diverse motor problems

Question 26

What happens if damage happens in between the uppermost and lowermost part of cerebellum?

Answer 26

Damage here can lead to errors in gaze and difficulty with tracking visual objects as the head moves.

Question 27

The language difficulties observed in split-brain patients?

Answer 27

The split corpus callosum prevents right-hemisphere visual areas from communicating with the language areas of the left hemisphere, so verbal responses to stimuli (shown to the left eye) are impossible. But they’re able to respond verbally to stimuli appearing in the right visual fields, because interhemispheric transfer isn’t required.

Question 28

Prosopagnosia?

Answer 28

unable to recognize faces.

Question 29

Astereognosis?

Answer 29

objects placed in the hand opposite the injured somatosensory cortex can be felt but cannot be identified by touch and active manipulation.

Question 30

Broca’s aphasia?

Answer 30

Difficulties producing speech. The ability to utter automatic speech is often preserved.

Question 31

Wernicke’s aphasia?

Answer 31

They produce plenty of verbal output, but their utterances tend to contain many paraphasia that make their speech unintelligible – it means that they make sound or word substitutions.

Question 32

Conduction aphasia (damage to part where info travels from Wernicke’s to Broca’s area)?

Answer 32

unable to repeat words or sentences. When these people attempt to repeat words they have heard, they are likely to produce incorrect phonemes substituting for correct sounds.

Question 33

Deep dyslexia?

Answer 33

errors in which people read a word as another word that is related in meaning.

Question 34

Surface dyslexia?

Answer 34

find it difficult recognize words in which the letter-to-sound rules are irregular.

Question 35

Where is Broca’s area?

Answer 35

Frontal lobe

Question 36

Where is Wernicke’s area?

Answer 36

Left posterior speech zone.

Question 37

Why can the muscles of the face be moved with greater precision than the biceps muscles?

Answer 37

Because the facial muscles have a lower ratio of muscle fibers to neurons.

Question 38

Mental rehearsal of a complex motor task in humans is associated with increased blood flow where?

Answer 38

Only in the supplementary motor area.

Question 39

Each structure of the basal ganglia contains?

Answer 39

a topographic representation of body musculature.

Question 40

Which part of the brain is responsible for our ability to track visual objects as the head moves?

Answer 40

The cerebellum

Question 41

The angular gyrus links…

Answer 41

the visual region and Wernicke’s area

Question 42

The dorsal roots of the spinal cord transmit which information?

Answer 42

Sensory.

Question 43

The ventral roots of the spinal cord contain?

Answer 43

Motor fibers.

Question 44

Spoonerism?

Answer 44

mixing up the order of sounds in one’s sentences.

Question 45

The motor plan?

Answer 45

a complex set of commands to muscles that is established before the behavior starts.

Question 46

Electromyography (EMG)?

Answer 46

fine-grained analysis of movements by recording the electrical activity of muscles. Muscles produce action potentials which explains why the electrodes can detect muscle activity.

Question 47

Closed-loop control mechanisms?

Answer 47

information from whatever is being controlled flows back to the device that controls it. This maximizes accuracy.

Question 48

Open-loop control mechanisms?

Answer 48

the activity is preprogrammed. No external forms of feedback. Maximizes speed. When there isn’t enough time to use feedback.

Question 49

What is the region where a motor neuron terminal and adjoining muscles fibers meet called?

Answer 49

The neuromuscular junction.

Question 50

What is the neurotransmitter at the neuromuscular junction?

Answer 50

Acetylcholine.

Question 51

Myasthenia?

Answer 51

disorder with a profound weakness of skeletal muscles. The disease first affects the muscles of the head, later paralysis of the muscles that control swallowing and respiration. The weakness happens because of the neuromuscular junctions are not working – the muscles aren’t getting the message to contract.

Question 52

Proprioception?

Answer 52

the perception of body movements and positions.

Question 53

Golgi tendon organs?

Answer 53

they detect overloads that threaten to tear muscles and tendons.

Question 54

ALS?

Answer 54

the motor neurons of the brainstem and spinal cord spontaneously start to die and their target muscles waste away. Gradually worsening paralysis until most skeletal muscles ceases to function. No treatment currently. About 10 % of ALS cases are hereditary.

Question 55

Apraxia?

Answer 55

the inability to carry out complex movements even though paralysis or weakness is not evident and language comprehension and motivation are intact. Can come from a stroke, Alzheimer’s, and developmental disorders of children.

Question 56

Parkinson’s disease?

Answer 56

a loss of facial muscle tone. Show few spontaneous actions and have great difficulty in all motor efforts. The hands may display tremors at rest. Show progressive degeneration of dopamine-containing cells. Symptoms can be reduced by operating electrodes into the brain (deep brain stimulation).

Question 57

Huntington’s disease?

Answer 57

the first symptoms are subtle behavior changes: clumsiness, and twitches in the fingers and face. Subtlety is rapidly lost as the illness progresses. Aimless movements of the eyes, jerky leg movements, and writhing of the body. As the disease progresses, intellectual deterioration, depression. Usually develops in a period of 15-20 years. Destruction of the basal ganglia. The disease is inherited – transmitted by a single dominant gene on chromosome 4. 50 % change of inheriting the gene.

Question 58

What is the right hemisphere specialized in?

Answer 58

Processing spatial information.
Also crucial for face perception, processing emotional aspects of language, and for controlling attention.

Question 59

Right-hemisphere lesions?

Answer 59

tend to produce a variety of striking impairments of spatial cognition

Question 60

Agnosia?

Answer 60

an inability to identify items, in the absence of specific sensory impairment.

Question 61

Left hemisphere specialization?

Answer 61

vocabulary and grammar.

Question 62

Left or right hemisphere damage lead to aphasia?

Answer 62

Left.

Question 63

Agraphia?

Answer 63

Trouble with writing.

Question 64

Alexia?

Answer 64

Trouble with reading.

Question 65

Connectionist model of aphasia?

Answer 65

views language deficits as resulting from disconnection between the brain regions in a language network.

Question 66

Motor theory of language?

Answer 66

propose that the left-hemisphere language zones are motor control systems that are concerned with both the precise production and the perception of the extremely complex movements that go into speech.