Lecture 18- Language Flashcards
What is lateralization?
Verbal behaviour is lateralized in the brain.
Most language disturbances occur after damage to the left side of the brain, regardless if they are left-handed or right-handed.
Which hemisphere is speech dominant in 90% of the population?
Left hemisphere
True or false?
Right hemisphere speech dominance is seen in 4% of right-handed people and 27% of left-handed people.
True
What does prosody means when talking about language?
It’s the rhythm, tone and emphasis in speech.
Prosody is typically a function of the right hemisphere, so people who have damage to the left hemisphere who cannot understand language can still understand prosody.
Name the agnosia:
- Disorder where people have great difficulty recognizing voices. It results from localized brain damage to the right superior temporal cortex.
Phonagnosia
What are the functions of the right hemisphere in language?
1) prosody : tone, rhythm, emphasis in language
2) Recognizing someone by their voice.
3) the comprehension of metaphors
What is an aphasia?
It refers to a disturbance in understanding, repeating or producing meaningful speech.
- Must not simply be caused by sensory or motor deficits or by lack of motivation.
- Must be relatively isolated
- Patient must recognize that others are trying to communicate with them. Must be somewhat aware of what is happening around them
Damage to sensory association cortex causes deficits in understanding language. The aphasia may be described as?
- Posterior aphasia
- Sensory aphasia
- Receptive aphasia
- Wernicke’s aphasia
- Fluent aphasia
Damage to the frontal lobe causes deficits in speaking. The aphasia may be described as?
- Anterior aphasia
- Motor aphasia
- Expressive aphasia
- Broca’s aphasia
- Non-fluent aphasia
What is included in the comprehension of a word?
Vision -What do dogs look like?
Auditory - What do dogs sound like?
Touch - What do dogs feel like?
Olfaction - What do dogs smell like?
Gustatory - What do dogs taste like?
Motor - How do dogs act? What does petting a dog entail?
Which areas, in order, are activated in language?
1) Primary sensory areas (first process sensory input)
2) Association cortex to make sense of the sensory input
3) Wernicke’s area in the perception of the word (Auditory)
4) Speaking words is located in Broca’s area
5) language comprehension —> posterior language area
Which area is activated in the perception of a spoken word?
Wernicke’s area
Which area is activated when speaking a word?
Broca’s area
Which area of the brain is activated in language comprehension?
Posterior language area
What does damage to the posterior language area do?
People can’t seem to understand the meaning of words anymore.
Ex: the concept of a dog is still known to them but the written or spoken word DOG will not be recognized by them.
What does the posterior language area do?
- It is critical for language comprehension.
- Neurons there activate the ensemble of neurons throughout sensory association cortices that store the representation (meanings) of specific words.
Where is the posterior language area located?
At the junction of the temporal, occipital and parietal lobes, around the posterior end of the lateral fissure.
What is Transcortical Sensory Aphasia?
- Damage to and around the posterior language area
- Failure to comprehend the meaning of words and an inability to express thoughts with meaningful speech.
- Word perception and speaking might be fine (without any comprehension of what is spoken)
- Can repeat words, read out loud without understanding and write with no understanding.
They can speak fluently (frontal lobe is fine), but they can’t comprehend what is said. They can repeat after you.
What is conduction aphasia?
-Really small aphasia
- Characterized by an inability to repeat the exact words you hear.
- Other than that, language is totally fine.
- Caused by damage to and around the arcuate fasciculus
Which part of the brain results in conduction aphasia?
Damage to the connection between Wernicke’s area and Broca’s area known as the arcuate fasciculus.
What does Wernicke’s area do in regards to language?
It is involved in the analysis of speech sounds and in recognition of spoken words. It’s the region of auditory association cortex on the left temporal lobe of humans
What is pure word deafness?
- REsults from damage to a small part of Wernicke’s area.
- Disorder of auditory word recognition. Inability to comprehend or repeat spoken words.
“I can hear you, but I don’t recognize the words you are saying. I have trouble repeating what you’re saying” .
-They can hear and recognize other sounds like a doorbell. They could read lips and they can speak fluently. Over time, their speech becomes awkward like a deaf person speaking.
What is Wernicke’s aphasia?
Results from damage to both Wernicke’s area and the Posterior language area —> features of transcortical sensory aphasia and pure word deafness.
- Poor language comprehension. Fluent speech production, but no meaning to what they say.
- Will never repeat what you just said.
- They are not typically aware of this problem and do not show must frustration to their problem.
- Also called receptive aphasia and fluent aphasia.
What is the main difference between transcortical sensory aphasia and Wernicke’s aphasia?
Wernicke’s aphasia cannot repeat what people just said to them and cannot recognize proven words while people with transcortical sensory aphasia can do those things.
