Exam 1: Aphasia

Acquired

Developed or learned; not naturally occurring

Acquired language disorder

Language disorder that occurs after individual has already acquired language; disorder when you lose a cognitive-linguistic skill previously had in the past

Cause of acquired language disorder

Neurological damage to brain

Neuroplasticity

The ability within the brain to constantly change both the structure and function of many cells in response to experience or trauma; greater in children than adults

Neurplasticity in children vs. adults

Children recover differently than adults; prognosis must be better for children because they have greater levels of neuroplasticity

Aphasia

Acquired language disorder

Dementia

A slowly progressive neurogenic disorder; may lead to a language disorder; can cause cognitive-linguistic deficits like seen in Aphasia, but NOT SAME as aphasia

Traumatic Brain Injury

Can result in acquired language disorder for example, cognitive communication disorders; usually not Aphasia

Language

Shared code for representing concepts through use of symbols and rule-based combinations of symbols

Symbols

Sounds, letters, and words that convey varied meaning depending on way we combine and sequence them; e.g. "knew vs. new" and "bark on tree vs. dog bark"

5 components of language

Semantics, Syntax, Morphology, Phonology, and Pragmatics

Semantics

Conceptual knowledge (what you know) about the meaning of words

Syntax

Rules that govern word-order e.g. grammar e.g. understanding that an adjective comes before a noun

Morphology

Rules that govern words at smallest unit of words (morpheme)/basic level of meaning e.g. add -s to dog to make plural

Phonology

Rules for combining speech sounds (phonemes) e.g. "j" never followed by consonant

Pragmatics

Rules that govern how language is used in conversation (people with Aphasia know rules but struggle in this area)

Communication

Exchange of ideas and fundamental to behavior (does not require language)

Speech; language

Adult communication is usually _______ and _______

Even when a language is disordered,

communication is still possible; SLPs need to support that

SLPs can ______ to make it work

Design/change brain

Nervous system

System that transmits signals between brain and rest of body and is composed of the central nervous system and the peripheral nervous system

Central nervous system

Part of nervous system that contains brain and spinal cord

Peripheral nervous system

Part of nervous system that consists of all parts of nervous system except for the brain and spinal cord

Brain

Part of CNS; composed of brain stem, cerebellum, and cerebrum

Brainstem

Connects cerebrum to spinal cord and consists of a midbrain, pons, and medulla; important for swallowing and speech production (cranial nerves) and plays a role in consciousness (e.g. being awake and direct) and controls heart rate, breathing, and blood pressure; not important for language

Spinal cord

Important for speech production and respiration, not language use; part of CNS

Cerebellum

Located at rear of brain and is part of motor system; important for modulating/regulating movement for speech production; role in language is not understood fully, but it does contribute in some way

Cerebrum

Largest and uppermost portion of brain divided into two halves: left and right

Cerebral hemispheres

Left and right sides of brain

Longitudinal fissure

Splits left and right sides of brain

Hemispheric specialization

Idea that each side of brain has specific and specialized abilities

Left hemisphere

Side of brain responsible for movement on right side of body; responsible for speech and language

Right hemisphere

Side of brain responsible for movement on left side of body

Damage to either left or right hemisphere can lead to...

Paralysis

Hemiparesis

Often co-occurs with Aphasia; Weakness on one side of the body; mild to severe

Hemiplegia

Often co-occurs with Aphasia; paralysis on one side of the body; severe

Right-handed people are dominant in which hemisphere? What about left-handed people?

Right-handed people are left hemisphere dominant; but left-handed people it depends

Corpus callosum

Thick band of fibers that allows left and right hemispheres to communicate

Cortex

Outer layer of cerebrum (aka gray matter) and contains gyri and sulci; place where speech and language occur in left side including both production and comprehension

Gray matter

Composed of cell bodies of neurons that make cortex gray (unmyelinated)

White matter

Under gray matter/cortex; coated with myelin and fat to help messages get sent to other parts of the brain

Gyri

Ridges, bumps of brain

Sulci

Grooves, valleys of brain

Gyri and sulci

Allow us to store lots of cortical tissue and neurons; act as anatomical landmarks in the brain

Subcortical cortex

Brain below the cortex; consists of basal ganglia, thalamus, and other structures; connect portions of the brain allowing them to connect to each other; white matter allows these structures to work

Frontal, Parietal, Temporal, and Occipital

Four lobes of the brain

Anterior (Rostral)

Towards front of body

Posterior (Caudal)

Towards back of body

Superior (Dorsal)

Towards top of body

Inferior (Ventral)

Towards bottom of body

Lateral

Away from middle of body

Medial

Closer to middle of body

Proximal

Closer to center of body

Distal

Further from center of body

Central sulcus (rolandic fissure)

Sulcus that divides frontal lobe from parietal lobe

lateral sulcus (sylvian fissure)

Sulcus that separates frontal lobe from temporal lobe and separates temporal lobe from parietal lobe

The frontal lobe is _____ to temporal lobe

Anterior and superior

Parieto-occipital sulcus

Sulcus that separates occipital lobe and parietal lobe

Occipital lobe

Lobe mostly dedicated to vision; separated from parietal lobe through parieto-occipital sulcus

Frontal lobe

Lobe dedicated to cognition and movement

Anterior frontal lobe

Portion of frontal lobe dedicated to cognition

Posterior frontal lobe

Portion of frontal lobe dedicated to movement

Pre-frontal cortex

Part of frontal lobe vital for thinking, planning, decision-making, and other executive functions; many connections coming to and from here to control emotions and cognition

Primary motor cortex

Also known as motor strip/area; the gyrus right anterior to central sulcus; like a headband going from right to left; plans, controls, and executes voluntary movement from opposite side of body; works with sensory strip to create movements for speech production

Motor homonculus

Representation of body parts proportionally and contralaterally based on how much movement they have; e.g. areas in face have a lot of movement because they are more complex

Pre-motor cortex

Anterior to motor strip; in charge of voluntary movements; supports motor strip to help speech and language

Supplementary motor cortex

Anterior to motor strip; in charge of fine and complex motor movements; supports motor strip to help speech and language

Broca's area

Founded by Paul Broca; refers to area right above lateral sulcus in left hemisphere and anterior to motor strip; plays primary role in language expression, known for motor speech area because it is essential to speech production; it allows us to speak fluently/easily; contributes to melodic line/prosody of speech; converts phonological lexical information into motor commands (e.g. have word, know phonemes you need, need to produce --> contributes to syntax)

Parietal lobe

Lobe that is posterior to frontal lobe and home to sensory cortex/sensory strip; areas in this lobe important for language

Sensory strip/Somatosensory cortex

Posterior to motor cortex; receives and processes sensory information (e.g. touch, pain, temp, etc.); gets contralateral input and is also proportional

Sensory homunculus

Representation of body parts contralaterally and proportionally based on how much they are used in sensory; areas get more representation when used more

Supramarginal gyrus

Gyrus important for phonological provessing and speech perception and repetition

Angular gyrus

Gyrus posterior to supramarginal gyrus; important for reading comprehension, writing, and role in our ability to use numbers/arithmitic

Temporal lobe

Lobe in charge of receptive language; responsible for auditory perception and interpretation of speech; hearing sound and finding out what it means; understanding/comprehensnion of speech; processes semantic and syntactic information and nonverbal sounds

Superior temporal gyrus (STG)

Gyrus located above middle temporal gyrus; home of primary auditory cortex

Middle temporal gyrus

Gyrus located between the superior and inferior temporal gyri

Inferior temporal gyrus

Gyrus located just inferior to the middle temporal gyrus

Primary auditory cortex

the region of the superior temporal lobe whose primary input is from the auditory system; hearing, process of pitch, tone, and volume; localization of sound; distinguishes between speech and non-speech; in both hemispheres

Bigger because this side is language dominant

Primary auditory cortex in left hemipshere is ______ because

Wernicke's area

Posterior portion of STG; located in left temporal lobe and where temporal, parietal, and occipital lobes intersect; very close to primary auditory cortex; has big role in language comprehension, and processing of phonologic, semantic, morphosyntactic structures; monitors output from Broca's area and evaluates for accuracy; named after Carl Wernicke who founded area

Perisylvian area

Area around sylvian fissure; considered the zone of language; anterior part = broca's area and posterior part = wernicke's area

Fasciculus (Fasciculi)

Neurons bundled together to connect one region of cortex to another within a hemisphere; they are "subcortical" meaning that they are in white matter

Superior longitudinal fasciculus

Connects frontal, temporal, parietal, and occipital lobes; has big role in motor activity and language

Arcuate fasciculus

Subdivision of superior longitudinal fasciculus; connects temporal, frontal, and parietal lobes; essential for repetition and contributes to ability to listen to what someone says and repeat what was said; contributes to ability to recognize language and respond appropriately; connects broca's area and wernicke's area

Many causes of Aphasia consists of disruptions in

Cerebral blood supply

Vascular system

System consisting of arteries and veins

Arteries

Oxygenated blood that brings blood from heart to brain

Veins

Deoxygenated blood that brings blood to heart

Brain is very vulnerable to changes in blood levels and O2 because

Brain can't function without oxygenated blood

Left/Right Vertebral Arteries

Arteries that supply posterior portion of brain with blood (brainstem, cerebellum, occipital lobe)

Left/Right Internal Carotid Arteries

Blood pumped through aorta and branches into these arteries

Left/Right External carotid arteries

Pumps blood and goes to scalp and face (on each side)

Circle of Willis

Special loop of blood vessels at base of brain that connects all major arteries bringing blood up to the brain; blood is dumped here; think "traffic circle"

Internal carotid arteries

Considered the "on ramps" of circle of willis that carry blood to brain

Other arteries

Considered the "off ramps" of circle of willis; leave and transport blood to other parts of the brain

Anterior cerebral artery

Artery that takes blood to frontal lobe

Middle cerebral artery

Artery that is biggest branch of internal carotid arteries; provides blood to majority of brain (language)

Posterior cerebral artery

Artery that takes blood to back of brain (part of temporal lobe and occipital lobe)

Circle of willis

acts as a safety valve for brain; even if blocked in one carotid artery and there is a reduction in blood, it can still go around to other side

If blockage occurs after circle of willis..

Blood supply can't get past because there is no safety valve; tissue gets damaged