Neural Substrates of Speech

Question 1

What is speech?

Answer 1

Verbal expression of thoughts and feelings using sound patterns decodable by listeners who share a common language

Question 2

Speech is ____motor

Answer 2

Sensori

Question 3

What are the 4 subsystems that comprise speech?

Answer 3

Respiration
Phonation
Articulation
Velopharyngeal (resonation)

Question 4

What is the purpose of the respiratory subsystem?

Answer 4

Provide airflow and pressure needed for sound generation

Question 5

How is breathing for speech/vocalization different from vegetative breathing?

Answer 5

Quick inspiration, long expiration

Question 6

Where are the cell bodies of the respiratory subsystem located?

Answer 6

Ventral (anterior) horn of the spinal cord

Question 7

Where are the cell bodies of the phonatory and velopharyngeal subsystem located?

Answer 7

Nucleus ambiguus CN X

Question 8

Where are the cell bodies of the oral articulators located?

Answer 8

Facial (CN VII)
Hypoglossal (CN XII)
Trigeminal nucleus (CN V)

Question 9

What muscles are the most important muscles for speech?

Answer 9

Muscles of inspiration (diaphragm and external intercostal muscles)

Question 10

What is the key structure of the phonatory subsystem?

Answer 10

Larynx

Question 11

What is the purpose of the phonatory subsystem for speech?

Answer 11

Creates vibration for acoustic buzz (voicing)
Vibration created by air pressure and flows driving the vocal folds into oscillation

Question 12

What muscles are involved in voicing of the phonatory subsystem?

Answer 12

Cricothyroid, lateral and posterior cricoarytenoid, thyroarytenoid, interarytenoid

Question 13

What nucleus is involved in phonation?

Answer 13

Nucleus ambiguus (CN X)

Question 14

What is the purpose of the oral articulatory subsystem?

Answer 14

Shape the oral and pharyngeal cavities to create a variable resonator
Generate a variety of sounds by constricting the airstream through the vocal tract

Question 15

The tongue muscles produce …

Answer 15

Most consonants and vowels

Question 16

The back consonants are produced by what muscles

Answer 16

Palatoglossus (tongue muscle)

Question 17

Bilabials (p,b,m), labiovelars (w), and labiodentals (f,v) are controlled by ___ nucleus and __ muscles

Answer 17

Facial nucleus, facial muscles

Question 18

What is the purpose of the velopharyngeal system?

Answer 18

Velopharyngeal port is rapidly opened and closed to meet phonetic needs during articulation

Question 19

Closing the velopharyngeal port is needed for production of

Answer 19

All vowels and most consonants

Question 20

Opening the velopharyngeal port is needed for production of

Answer 20

Nasals

Question 21

What velopharyngeal nerves are involved in speech?

Answer 21

Nucleus ambiguus (CN X)
Pharyngeal plexus (CN IX, X, XI)
Mandibular nerve (CN V) trigeminal motor nucleus`

Question 22

What motor speech disorder is associated with LMN damage?

Answer 22

Flaccid dysarthria

Question 23

Flaccid dysarthria is characterized by

Answer 23

Muscle weakness, hypotonia, reduced reflexes, atrophy, fascicualtions

Question 24

What deficits are common with flaccid dysarthria?

Answer 24

Hypernasality, imprecise consonants, breathiness, monopitch, harsh or hoarse voice quality, short phrases

Question 25

Flaccid dysarthria is typically caused by

Answer 25

CN damage (stroke, tumor, TBI), degenerative diseases like ALS

Question 26

What motor speech disorder is associated with upper motor neuron damage?

Answer 26

Spastic dysarthria

Question 27

Spastic dysarthria is characterized by .... most prevalent with .....

Answer 27

Increased muscle tone, hyperreflexia, spasticity Bilateral UMN damage

Question 28

What speech characteristics are common with spastic dysarthria?

Answer 28

Excess and equal stress, slow rate, imprecise consonants, distorted vowels, monopitch, monoloudness, impact on prosody, nasal, hoarse

Question 29

What subcortical structures are involved in speech?

Answer 29

Reticular formation Periaqueductal grey Thalmus Basal ganglia Cerebellum

Question 30

What subcortical structures are involved in vocalization?

Answer 30

Periaqueductal grey (modulatory role) and reticular formation (muscle activity), both in brainstem

Question 31

What are the subcortical structures involved in speech that are in the thalamus?

Answer 31

VPM: somatosensory info from head and neck to primary somatosensory cortex VPL: somatosensory info from chest wall to primary somatosensory cortex MGN: auditory information to primary auditory cortex of temporal lobe

Question 32

What subcortical structures involved in speech are in the basal nuclei?

Answer 32

Collection of interconnecting nuclei 1. Motor Circuit (important for movement sequences) 2. Executive/cognitive circuit (important for buffering and sequencing long utterances) 3. Emotional/motivation (providing urge to speak)

Question 33

What is hyperkinetic dysarthria?

Answer 33

Caused by damage to basal nuclei, issue with direct pathway

Question 34

Why does hyperkinetic dysarthria cause more movement?

Answer 34

Overactivity of the direct pathway provides strong input to the thalamus = strong thalamic drive to motor cortical areas for movement leading to excessive movement

Question 35

What is hypokinetic dysarthria?

Answer 35

Caused by damage to basal nuclei Issue with indirect pathway

Question 36

Why does hypokinetic dysarthria cause less movement?

Answer 36

Indirect pathway dominance leads to suppression in the movement

Question 37

Subcortical structures involved in speech: Cerebellum function

Answer 37

Important for control of skilled and precise movement Coordinates both covert and overt speech

Question 38

What happens to speech with damage to the cerebellum?

Answer 38

Ataxic dysarthria

Question 39

The key cortical structures associated with speech are housed in the ____ lobes

Answer 39

Temporal, frontal, parietal

Question 40

Neurons within the primary motor cortex send projections directly onto LMN located in the brainstem via the ___ tract and the spinal cord via the ___ tract

Answer 40

Corticonuclear Corticospinal

Question 41

Primary somatosensory cortex is located within ___ lobe immediately ____ to central sulcus

Answer 41

Parietal Posterior

Question 42

Primary somatosensory cortex receives proprioceptive and tactile information from the ___ side of the body via the VPL nucleus of the thalamus for structures below the ___ and VPM nucleus for ____ and ___ regions

Answer 42

Contralateral Neck Head, neck

Question 43

Broca's area is located in

Answer 43

Inferior frontal gyrus

Question 44

What is Broca's area responsible for?

Answer 44

Speech motor control, semantic and syntactic processing of language and reading

Question 45

Damage to Broca's area leads to

Answer 45

Apraxia of speech (difficulty programming speech motor movements in absence of motor weakness) Broca's aphasia (difficulties expressing oneself using language)

Question 46

What is the function of supplementary motor areas for speech?

Answer 46

Planning of speech and phonemes

Question 47

What happens with damage to supplementary motor areas of speech?

Answer 47

Apraxia with incorrect phonemes, impaired ability to say what they want to say (prepositional speech)

Question 48

What is the function of anterior cingulate cortex? What happens with damage?

Answer 48

Function: initiate speech, control of emotional components of speech Damage: temporary or permanent akinetic mutism (cannot initiate speech)

Question 49

What is the function of the supramarginal gyrus?

Answer 49

Language processing, speech motor control Sound to articulation mapping Compare expected sensory feedback with actual sensory feedback

Question 50

Where is the insula?

Answer 50

Deep within the lateral sulcus

Question 51

What is the function of the insula?

Answer 51

Motivational and affective influence over speech and language Programming and generation of speech movements