Lecture 1 Flashcards
Aphasia
acquired disorder of language caused by brain damage
Can affect comprehension (reception), expression of language or both aspects
All modalities can be affected (spoke, written, gestural- if someone is deaf they may lose the ability to sign
5 domains of speech sound production
Respiration (tier 1) Resonation (1) Phonation (2) Articulation (3) Prosody (3)
5 domains of language
Pragmatics Phonology Syntax Semantics Morphology
5 domains of cognition
Executive function Memory Attention Problem solving Sequencing
Considerations for Aphasia:
Clinical importance
Clinically important: can be a confusing disorder (historically) and it is often thought of demographically as a disorder of aging, but we know that it can occur in all ages. We also know that since this is an acquired disorder of language, language must be in place
Considerations for Aphasia:
Scientically important
- Scientifically important: there is a relationship between the brain and language, area affected and how language is impacted. Allows us to understand how the brain controls and modulates language functions
Early Perspectives on Aphasia
- Misunderstood intially (ventricles controlled cognition or caused by tongue paralysis)
- Gesner (1770) called it speech amnesia (language amnesia would be more accurate)
- Gesner claimed that lang. was controlled by the brain
Phrenology
associates mental and intellectual functions topographically on the skull
Aphasia and Dysarthria
Aphasia- Language aspect Dysarthria- Speech aspect Pt. can have both Cortical stroke= spastic dysarthria Brainstem stroke= flaccid dysarthria
Phrenological organs
does not hold up
Paul Broca
- French neurosurgeon that linked frontal lobe and left brain to lang. production
- Broca’s research focused on lower portion of frontal lobe, Broca’s area.
- Broca’s aphasia is caused by injury to that frontal area (area 44)
Communication
By itself, it is a total brain function
Broca’s Research
- Termed Aphasia as Aphemia
- Caused: Reduced speech fluency, agrammatic or telegraphic speech, many language production errors, and/or limited impairment to comprehension of spoken language (normal or almost normal)
Carl Wernicke
- German scientist who described Wernicke’s Aphasia, the form opposite of Broca’s
- Lesions or injury to the posterior portion of the left superior temporal gyrus cause Wernicke’s aphasia
Broca’s Aphasia
Affects anterior (pre-motor area), nonfluent aphasia Speech is very choppy, telegraphic, doesn't flow easily Cry a lot because they know they are wrong pseudobulbar affect- find it with broca's aphasia and spastic dysarthria
Wernicke’s Aphasia
Affects posterior portion of the brain (sensory motor strip)
Speech is fluent but not coherent
Wernicke patients are fluent but they do not make any sense- called cocktail party speech
comprehension is affected so they have no idea if their responses make sense
Wernicke’s Work
- Wernicke called his aphasia sensory aphasia
- Causes: fluent, but meaningless speech, grammatically correct speech, problems understanding language, difficulty comprehending spoken or read material
- Wernicke stated that other aphasias existed, TCM, conduction Aphasia, and TCS
- TCM
2. TCS
- Transcortical Motor Aphasia- anterior damage
- Transcortical Sensory Aphasia- posterior damage
both go through wernicke’s area
Handedness Theory
Joannes Nielson suggested that language was in the hemisphere opposite of the preferred hand.
Most people are left hemisphere dominate for language (very seldomly right)
Hypothesis has been discounted and handedness is not a reliable indicator of hemispheric language dominance
85% of the population is right handed and 15% of the population is left handed
~15% of the (15% left-handed persons) are right hemisphere dominate for language
Cerebrum (The Brain)
AKA- cerebral cortices or cortex
computer of your body
The cerebrum is the final integrative and executive structure of the nervous system
The cerebrum is responsible for all higher brain functions (most in the frontal lobe):
everyday thinking, speaking, judgment, logical reasoning, lang. production, emotional experience, abstract reasoning, artistry, attention, mathematical reasoning, scientific achievement, problem solving, memory, lang. comprehension, and executive functioning
Brain Facts
- brain contains billions of neurons w/ trillions of synapses
- Brain weighs 3-3.5lbs (1-2% of body mass)
- 6 layers (outside is gray matter)
- 2 hemispheres connected by corpus callosum (thick myelinated axons)
- Regions within the hemispheres are connected by shorter association fibers
- Surface of the brain is comprised of gyri and sulci
Landmarks on the brain
- Gyri
- Sulci
- LCF
- Meniniges
- hills, folds, and convolutions
- grooves, valleys, and fissures
- longitudinal cerebral fissure- separates the left/right hemispheres
- Covers the brain (dura keeps the brain together in its structure)
- Fissure of Rolando
- Lateral Cerebral Fissure
- Perisylvian Area
- Central Sulcus- divides anterior and posterior aphasias. It runs laterally downward, and forward dividing the anterior half of the brain from the posterior half.
- AKA- Sylvian Fissure which moves laterally and upward (along the superior temporal gyrus)
- Regions surrounding this area are especially involved in speech, language, and hearing. Area around the sylvian fissure (includes broca’s area)