Lecture 8 and 9: Language Disorders Flashcards
What is Aphasia?
- Disorder affecting language and that is caused by damage to the brain
- Can involve problems with written and spoken language
- There are two types:
- Language
- Speech
What is Language Aphasia?
Language Aphasia refers to the disorder of language such that the output is linguistically incorrect.
What is Speech Aphasia?
Disorder of language where the muscles are weak or uncoordinated such that it impaires the language output.
Who was Paul Broca, and what did he do?
- Paul Broca was the first to demonstrate that aphasia was linked to specific lesions.
- Lesions primarily on the left hemisphere
- Broca’s Aphasia
What is another name to refer to Broca’s Aphasia?
Nonfluent Aphasia or Expressive aphasia
Broca’s Aphasia
- Affects the output:
- Reduced speech production
- slow, effort speech
- not fluent
- poor articulation
- No grammatical structure (aggrammation)
- Problems with syntac
- Similar deficits in writing
- Sometimes paralysis of the right side of the body
- Reduced speech production
- Keeps :
- Comprehension
- Musical capasities
- Word searching
Wernicke’s Apahasia
- Speech is empty
- converts no meaning
- Failure to understand language written or spoken
- Lost semantic meaning of words
- No paralysis
- The speech output unaffected
- Neologisms: made up words
- Paraphasia
What is another name to refer to Wernicke’s Aphasia?
Receptive Aphasia
What is Paraphasia?
Error in word usage.
What are two types do Paraphasia?
- Phonemic Paraphasia
- Verbal Paraphasia
What is a phonemic paraphasia?
When you change 1 sound of a word.
Examples. Spoot instead of spoon
What is a verbal paraphasia?
Change the whole word
ex) Spoon instead of fork
What was Wernicke Theory?
- According to Wernicke:
-
Broca’s Area Contains the rules and code for articulation
- Located in front of motor areas for face, tongue, lips, etc
-
Wernicke’s Area Involved in the recognition of the patterns of spoken language.
- Located next to the hearing area
- The two areas MUST be connectected.
-
Broca’s Area Contains the rules and code for articulation
What is Fluent Aphasia?
- No problem producing speech
- No problem comprehending language
- Sentences has no meaning
- Contrary of nonfluent aphasia (Broca’s Aphasia)
What is Conduction Aphasia?
- Fluent speech
- Have some paraphasia
- Writing is fluent
- Comprehension intact
- Deficits:
- Sentence repetition
- Cause:
- Disconnection between Wernicke and Broca’s (Posterior temporal areas and inferior frontal areas)
- Damage to the arcuate fasciculus
- Broca’s and Wernicke’s areas are intact
- Lesions:
- inferior parietal lobe near the supramarginal gyrus
What happens if you as a question to a patient with conductive aphasia?
- They will understand and will be able to answer
What happens if you ask a patient with Conductive Aphasia to repeat a sentence?
They will have problems to repeat it.
Describe the experiment by Weiler that tested the ability of aphasic patients to map articulation with sound.
- 100 aphasic patients
- Procedure:
- Tested mapping sound to articulation
- Results:
- 2 types (dorsal vs ventral):
- Parietal lesions (supramarginal gyrus):
- Speech is not perfect
- paraphasias
- comprehension was problematic
- Concluded that paraphasias resulted from disconnection
- Speech is not perfect
- Damage anterior and intermediate temporal areas:
- Sound to meaning problems
- Parietal lesions (supramarginal gyrus):
- 2 types (dorsal vs ventral):
Julia’s Case
- Had a stroke
- Can talk but there are things she can’t name
- Comprehension is good
- Problems with linking words and saying the words that she is thinking about
- Lesion:
- Parietal cortex
- Parietal lobe is the dorsal pathway for language (sound-to-meaning mapping)
- Arcuate and SLF
- Problem with repeating sentences
- Activation of ventral pathway, show they are intact
- She has problems with the motor aspect
What was something curious about Julia’s case?
- It was noticed that the anterior part of the temporal lobe was more activated
- this is the area associated with memory
- She was relying more on the meaning to be able to say it
What is Apraxia of speech?
- Impairment with articulation
- Impairments in the coordination and planning of speech movements
- Symptoms:
- Articulatory errors
- Lesion:
- Insula (left precentral gyrus of the insula)
- Intact:
- Ability to perceive sounds
What was the study that Donkers did to study Apraxia of speech?
- 25 stroke patients with apraxia of speech
- Procedure:
- Scanned brains to find the common lesion site
- Insula
- Scanned brains to find the common lesion site
- Conclusion:
- Role of the insula in articulatory planning
- More specifically the precentral gyrus of the insula
- Role of the insula in articulatory planning
True or False
The Insula is separated into many gyri?
True! It has its own precentral gyrus which is important for articulation planning
What happens if you isolate the speech area?
- Somewhat the contrary of the Conduction area
- Peri-Sylvian language areas were separated and disconnected from the rest of the brain.
- Components of Peri-Sylvian area were intact
- No language comprehension
- No spontaneous speech production
- Able to repeat perfectly what was said to them
- Able to complete sentences
- Able to learn new words (hippocampus)
-
Note:
- Rest of Temporal lobe is involved in comprehension of more complex language
- So in this case, the comprehension areas of the temporal lobe are not connected to the STG which transmit the auditory information to produce language in the frontal lobe via the FTexcF
- Inferior Parietal lobe:
- Role in syntactic and phonological processing
- Connections between Parietal and Frontal lobes allows word retrieval
- Rest of Temporal lobe is involved in comprehension of more complex language
How can you isolate the speech area?
By Carbon monoxide poisoning, it affects myelin and could kill cells and cause permanent damage.
What are the components of the Peri-Sylvian language areas?
- Around the Sylvian fissure
- Broca
- Wernicke
- Arcuate Fasciculus
- Hippocampus
What do lesions on the right hemisphere causes?
- Patients understand what is said but not how it is said (intonation)
- Music perception
- Problems:
- Prosody or cadence and intonation of speech and pragmatics
- Flat intonation
- Fail to comprehend emotional nuances
- sarcasm
- irony
- humour in speech
True or False
Right-handed people can have the language function on the right hemisphere.
True, 4% of right-handed people. The other 96% have the language function on the left side.
True or False
Left handed people will never have language functionality in both hemispheres.
False, 15% of left handed have language functionality bilateral. The rest 15% and 70% are on the right side and left side respectively
True or False
In young children, you can already see the lateralization of language. In other words, if they damage their non-dominant hemisphere, they would not show language deficits.
False, damage in either hemisphere can cause language deficits in young children.
True or False
If a young child has great damage on their left hemisphere, they will never be able to develop their language functionality to that of a normal child.
False, even if they severely damage their left hemisphere, young patients can recover language functionality
Here is an image of the development of Sentence comprehension. Notice how the lateralization occurs…
What is Dyslexia?
- Difficulties in the acquisition of literacy
- Impairments:
- speech processiong on taks that require manipulation and memory of speech sounds
- low-level visual procession
- ex: fast moving objects
- Cause:
- Unknown for the moment
What is Developmental Dyslexia?
- Symptoms:
- unexpected difficulty with reading in children and adults
- Cause:
- Due to different reasons
What is the difference in brain activation between normal people and dyslexic people?
By taking PET scans of the reading related area of the brain, it was noticed that there was less activation of the area 44/6 (articulation) and in the ventral occipito-temporal areas
What happens when we read?
- The information comes from a visual stimuli
- The visual structures are then transformed and sent to a specialized area for reading: Visual Word Form area
- Temporal lobe:
- sentence comprehension (both for reading and hearing)
- Ventral occipitotemporal area (Visual Word Form area):
- Activates when written words are presented to adults
- Temporal lobe:
What is Alexia?
- Symptoms:
- the lost ability to read and write
- Good vision
- No aphasia
- Lesion:
- Angular Gyrus
What is Agraphia?
- Impairment to write
What is Pure Alexia?
- Symptoms:
- Can’t read
- Can write, can’t read what they wrote
- Right visual field defect
- Lesion:
- Left visual cortex + posterior portion of the CC
Who studies Pure Alexia?
- Dejerine
- Conclusion:
- written language can only reach the right hemisphere and there was no transfer to the language hemisphere.
Who studied Alexia?
- Dejerine
- Conclusion:
- Two paths for:
- “Seeing language”:
- Retina → Striate cortex →Secondary visual areas → Angular gyrus (where the visual information is presented in space)
- “Hearing language”:
- Ears → Primary Auditory Area → Wernicke’s Area
- “Seeing language”:
- Two paths for:
What is VWFA? And what happens when there is a lesion on the VWFA?
- Location:
- Occipito-temporal area
- Proximity and connections to spoken language areas
- Function:
- Activates when written words are presented to adults
- Why?
- This area has a preference for high-resolution shapes
- Sensitivity for line configurations
- Lesion:
- Pure Alexia
Who is Stanislas Dehaene? And what did they do?
- Studied kids that were non-readers
- When presented with words, the same object recognition areas would be activated
- 6-year-old kids who are readers:
- Start to see activation in the fusiform area which gets bigger and bigger as you get expertise in reading
- Gets specialized for words
- Start to see activation in the fusiform area which gets bigger and bigger as you get expertise in reading
- He had this recycling hypothesis which involves the fusiform area to become more active in reading as you gain expertise
Here is an image showing the modern vision of the cortical networks for readings:
What is Developmental Dysgraphia?
- Acquisition of writing skills
- Developped
- Symptoms:
- Handwriting impairments
- Can also affect spelling
- Lesions:
-
Supramarginal gyrus
- Phonological agraphia
- inability to write nonwords when dictated
- Phonological agraphia
-
Angular gyrus
- Lexical agraphia
- better spelling of nonwords and regular words compared to non-regular words
- Lexical agraphia
-
Superior parietal lobule
- Apraxic agraphia
- Movement plans of writing
- Apraxic agraphia
-
Supramarginal gyrus
What is agraphia?
- Acquired disorder: lesion
- Impairment in writing
- Lesion:
- Two sources:
- Don’t remember how to write
- Motor aspect
- Apraxic agraphia
- Two sources:
Lesions in certain areas and writing disorders:
- Superior Parietal Lobe:
-
Spatial agraphia or afferent agraphia
- Spatial disorganization of writing
-
Spatial agraphia or afferent agraphia
- Supramargina gyrus:
-
apractic agraphia
- shape of written characters
- recognizable
-
apractic agraphia
- Suplementary Motor Area
-
Motor agraphia
- hesitations, trembling, self-corrections
- shape of characters are often unrecognizable
-
Motor agraphia
- Insula:
- Complex planification
- linguistic errors and impairment in the motor aspects of writing
- Problems with planning of motion
