SP 133: Module 2: Cortical And Subcortical Structures

Proprioception, Auditory Sensation

Sensory examples when saying P, D, and N

Proprioception, Auditory Sensation

Sensory examples when saying P, D, and N

Vibration

Sensory examples when saying D: Feel the ____ of vocal folds. There is a___ component in /d/

Nasal Vibration

Sensory examples when saying N: The ____ component is done inside the ___

Innervation, Complexity, Speed and Force Output, Precision and Type of Neural Control

Several Key Difference of Speech and Trunk/Limb Movement:

Cranial Nerves | Spinal Nerves & Cranial Nerves

Diff of Speech and Trunk/Limb Movement: innervation

More Complex (more movements) | Less Complex

Diff of Speech and Trunk/Limb Movement: Complexity

Speed Output | Force Output

Diff of Speech and Trunk/Limb Movement: Output

More Precise | Less Precise

Diff of Speech and Trunk/Limb Movement: Precision

Ipsilateral & Contralateral | Contralertal

Diff of Speech and Trunk/Limb Movement: Type of Neural Control

initiate, plan

MOTOR PLANNING FOR SPEECH: In order to speak, first, we need to ____ movement and ___ what the movement of the articulators will be.

PREMOTOR AREA / PREMOTOR CORTEX

MOTOR PLANNING FOR SPEECH: function: PREPARATION to do the movement: coordinating with the sensory area: active in motor routines involving visual or somatosensory input (uses info from sensation to guide,, like feedback)

SUPPLEMENTARY MOTOR AREA

MOTOR PLANNING FOR SPEECH:

function: motor planning activities: sequencing or mapping the sounds for production

phonetic

A ____ difference will entail that a phone has changed, but it has nothing to do with the meaning

phonemic

A ____ difference will entail that the phone change also changes the meaning of a word. Highly context-specific: in some context, there might be a phonemic difference; in some, there might not be a phonemic difference

phonetic

PHONETIC VS PHONEMIC: /buɛndʒɑ/ vs /buendɪɑ/

phonemic

PHONETIC VS PHONEMIC: /pɑlɔ/ vs /pɑtɔ/

BROCA’S AREA

Believed that it has a major function in articulation or in motor speech production.

phonology, phonetic encoding (no regard to meaning), motor planning and coordination of articulation

Initial thoughts of relevance (WRONG) of BROCA’S mediating link between phonemes and motor movements (not responsible of actual speech production)

Auditory Cortex -> Broca's Area -> Premotor Cortex -> Motor Cortex

Flinker et. al: sequence of activation of the areas: Broca's Area

PRIMARY MOTOR CORTEX

Responsible for making the muscles necessary for speaking move: Active in actual speech production

Nose, Tongue, Larynx, Face, Jaw, Lips, Oropharynx

PRIMARY MOTOR CORTEX: Handles the movement of articulators and respiratory organs for speech to occur

motor homunculus

The ______ includes the muscles of speech: articulators are very close to one another, responsible for making and coordinating the movements of the muscles required for speaking.

Somatosensory Cortices -> Broca's Area (linking phonemic seq and info to motor) --> Premotor Area (when you want to initiate) -> supplementary motor area (planning & sequencing) -> Primary Motor Cortex (movement of articulators)

Cortical Structures Pathway

CORTICOSPINAL TRACT

PYRAMIDAL SYSTEM (down to articulators): Major pathway for all movements of the trunk and limb (primary motor cortex -> corticospinal tract -> upper & lower motor neurons -> muscle (then contracts)): lungs are handled

CORTICONUCLEAR TRACT

PYRAMIDAL SYSTEM (down to articulators): muscles involving speech production, innervates all of CNs, ipsilateral & contralateral

UPPER AND LOWER MOTOR NEURONS

upper and lower motor neurons.

When the neuromotor signals is already in the tract, it goes to the

neuromotor impulse from the PMC -> corticonuclear tract -> upper motor neuron -> lower motor neuron -> muscle fiber of the tongue -> under contraction to move

Pathway: Muscle fiber of the tongue.

UPPER MOTOR NEURONS

Nerves that are contained within the CNS (direct activation pathway) (in the spinal cord still), Can transfer impulses through the LMNs

LOWER MOTOR NEURONS

Nerves that send motor axons outside the neuraxis (final common pathway), Ones connected to the actual muscle fibers for contraction

ipsilateral

The corticonuclear tract has more ____ fibers compared to the corticospinal tract

upper brainstem level

Corticonuclear and corticospinal tract separate (decussation) at the ____ ____ ____

bilaterally

Muscles for the upper face, jaw, diaphragm, larynx, and pharynx are more ____ innervated.

contralaterally

Muscles for the lower face (trunk and limb) are primarily ____ innervated

If one is damaged, the other side can still function

Function of Bilateral Input

most speech muscles move bilaterally (move both sides and at the same time)

Why are muscles of speech production bilaterally innervated

bilateral innervation

Corticonuclear Innervation in the Cranial Nerves for Speech: Trigeminal (V)

bilateral and contralateral innervation

Corticonuclear Innervation in the Cranial Nerves for Speech: Facial (VII)

bilateral innervation

Corticonuclear Innervation in the Cranial Nerves for Speech: Glossopharyngeal (IX)

bilateral innervation

Corticonuclear Innervation in the Cranial Nerves for Speech: Vagus (X)

contralateral innervation

Corticonuclear Innervation in the Cranial Nerves for Speech: Spinal accessory (XI)

bilateral innervation and contralateral innervation (only genioglossus)

Corticonuclear Innervation in the Cranial Nerves for Speech: Hypoglossal (XII)

Somatosensory Cortices → (Broca’s Area) → Premotor Area → Supplementary Motor Area → Primary Motor Cortex → Corticonuclear Tract/Corticospinal Tract → UMN → LMN → Muscle Contraction (speech/respiratory)

Full Neuromotor Pathway

sensation

NEUROSENSORY SYSTEMS FOR SPEECH: In order to do movements, first you must be able to have ___ that would be coming from outside and inside your body

Exteroreceptors

CHARLES SHERRINGTON'S SCHEME (Types of Sensation): Mediates sounds, sights, smell, and cutaneous sensations (basic senses); sounds to hear for communication, sight for communication

Proprioceptors

CHARLES SHERRINGTON'S SCHEME (Types of Sensation): Mediates deep somatic sensations from receptors that are beneath your skin; feeling movement of body

Interoceptors

CHARLES SHERRINGTON'S SCHEME (Types of Sensation): Responsible for sensation for visceral pain, pressure and distensions, responsible for organ senses

exteroceptors and proprioceptors

CHARLES SHERRINGTON'S SCHEME (Types of Sensation): among those, 2 are very important for speech production:

lateral and anterior spinothalamic tract

TRACTS FOR EXTERORECEPTORS: Somatic (body) sensations will travel through the ____ ___ ____ ____ ____

cranial nerves

TRACTS FOR EXTERORECEPTORS: Facial sensation will travel through the

cranial nerve V, VII, IX, X for sensations

TRACTS FOR EXTERORECEPTORS: Facial sensation: cranial nerves: what in particular?

V = Pain, temperature, touch to face, VII = Proprioception to face

Sensory Innervation of the Speech Mechanism: Facial

V = Touch to anterior two thirds, IX = Touch to posterior third

Sensory Innervation of the Speech Mechanism: Tongue

IX = Sensory to soft palate

Sensory Innervation of the Speech Mechanism: Palate

IX = Sensory to lateral and posterior pharyngeal walls, X = Sensory to lower two thirds of pharynx (forms pharyngeal plexus with cranial nerve IX)

Sensory Innervation of the Speech Mechanism: Pharynx

X = Sensory to most of the laryngeal muscles

Sensory Innervation of the Speech Mechanism: Larynx

Proprioception

Human Proprioceptive Pathways: Allows temporal and spatial comprehension among body parts = articulators must be relatively felt by one another

Two-point discrimination

Human Proprioceptive Pathways: Cognition of adjacent points on dermis: determine which is which or which is where?

Vibratory Sensation

Human Proprioceptive Pathways: Sensory pathway to detect vibrations by touch = some speech sounds use vibration

Form perception

Human Proprioceptive Pathways: Recognition of objects by touch

SPINOCEREBELLAR PATHWAY

PROPRIOCEPTIVE PATHWAYS: Lesser importance in human neurology because there is usually poor localizing information available about these tracts

DORSAL ROOT PATHWAY

PROPRIOCEPTIVE PATHWAYS: Conscious proprioception, two-point discrimination, and form perception have been called the sensory modality of the dorsal root pathway; more important pathway for sensory modalities, particularly proprioception

BASAL GANGLIA

SUBCORTICAL STRUCTURES: suppression of an unwanted movement (indirect pathway) and initiation of a desired movement (direct pathway)

dopamine

SUBCORTICAL STRUCTURES: BASAL GANGLIA: both pathways are regulated by

normal and regulated movement

SUBCORTICAL STRUCTURES: BASAL GANGLIA: “proper function of the basal ganglia is crucial for _________ of the speech musculature”

akinesia

EFFECTS OF BASAL GANGLIA ON SPEECH: decreased activity of the direct pathway will lead to: total lack of movement

bradykinesia

EFFECTS OF BASAL GANGLIA ON SPEECH: decreased activity of the direct pathway will lead to: very slow writhing movement

dyskinesia

EFFECTS OF BASAL GANGLIA ON SPEECH: decreased activity of the direct pathway will lead to: uncontrolled/spastic like unwanted movements

athetosis

EFFECTS OF BASAL GANGLIA ON SPEECH: decreased activity of the direct pathway will lead to: writhing movement

reduced ability to suppress unwanted movement

EFFECTS OF BASAL GANGLIA ON SPEECH: decreased activity of the indirect pathway will lead to: any unnecessary movements that the articulators might have can potentially occur

coordination of voluntary motor activity

SUBCORTICAL STRUCTURES: CEREBELLUM: FUNCTIONS FOR SPEECH: cerebellum controls the equilibrium and muscle tone (not too relaxed = lethargic, not too tense = difficulty initiating)

motor learning

SUBCORTICAL STRUCTURES: CEREBELLUM: FUNCTIONS FOR SPEECH: learn how to speak specific sounds, learned by repetition

motor memory mechanisms

SUBCORTICAL STRUCTURES: CEREBELLUM: FUNCTIONS FOR SPEECH: ataxia of extremities and asynergy are prominent if there are issues in the cerebellum; ataxia = drunk-like quality of speech, decomposition of movements (jerky/rough)

SERVOMECHANISM THEORY - SPEECH REGULATION

during speaking, we often correct the way that we produce speech sounds (feedback) = speech -> auditory system -> regulate correctness -> auditory mechanisms -> brain -> corrects

closed loop system

SERVOMECHANISM THEORY - SPEECH REGULATION: output is returned as input to control further output

open loop system

SERVOMECHANISM THEORY - SPEECH REGULATION: output is pre-programmed and is not matched back to the system: as we develop, we encounter errors, corrections become ingrained, outputs are regulated, less chances for those errors to occur

CLS and OLS

SERVOMECHANISM THEORY - SPEECH REGULATION: for speech, both ______ are used to serve as speech regulation mechanisms