Flashcards in Language Deck (18):
What is aphasia?
The partial or complete loss of language abilities following brain damage
What is Broca's area and Broca's aphasia?
Broca's area is often in the left hemisphere and responsible for producing language. Broca's aphasia results form damage to this area and leaves a person unable to produce speech
What is Wernicke's area and aphasia?
Wernicke's area is for language comprehension, often in left hemisphere. Damage leads to wording aphasia
Who is Wada? What'd he do?
Wada developed a method to study lateralization of language. He injects anesthesia into internal carotid artery of awake patient (sodium amytal) and patients would go mute. Can do this to left or right side of brain and work out which side is dominant in langauge, he found it was linked to handedness.
What are other names for Broca's aphasia?
- Anterior aphasia
- Non-fluid aphasia
What are the symptoms of Broca's aphasia?
anomia (difficulty finding words)
paraphasia (substituting sounds or creating wrong word)
Leaving out grammar, often grammar that they leave out is hard for them to understand which leads some people to think that Broca's aphasia may be a agrammatical disorder
What are symptoms of Wernicke's aphasia?
Trouble comprehending spoken and written language. Lots of paraphasia and anomia. Semantics effected.
What is the Wernicke-Geschwind model and its connectionist account of thinking?
Geschwind thought about Broca and Wernickie aphasias and produced this model in extension to Wernicke's own about language production. Auditory cortex recognizes sound and Wernicke's area then makes that sound a word by giving semantics. Axons sweep around the angular gyrus to Broca's area where code is made to motor cortex and word is repeated out loud.
What are the axons extending from Wernicke's area, around angular gyrus to Broca's area called?
What happens to words that are read and then spoken aloud?
The information travels from the visual cortex to the angular gyrus and THEN to Wernicke's area. Then around the angular gyrus to Broca's area and then to motor cortex etc.
What is conduction aphasia?
Where arcuate fasciculus is damaged. Unable to repeat spoken words because of disconnection between Wernicke's and Broca's area
What is a problem of the Wernicke-Geschwind model of language production?
It is often thought of as an oversimplification. For example subcortical paths may play a part, there are instances when reading that information travels straight from the primary visual cortex to Broca's area. Damage to speech depends on the extent of local damage around areas as well. Cortical areas will often compensate for lost language cortical areas and speech function can come back. Also it has been found that comprehension and language production isn't so clear cut as W-G proposed. If damage is done purely to Broca's area, there might be some comprehension loss as well as speech production loss.
Which structure of the brain is language most associated with? Are there any anatomical differences based on lateralization?
The Sylvian fissue. It is generally longer and shallower on the left hemisphere (Geschwind and Levitsky)
What is the planum temporale? How is it in dyslexic people?
Geschwind and Levitsky found regions in the superior temporal lobe that are asymmetric between the left and right hemisphere. It is 3x larger in the left hemisphere than the right. Found that people with dyslexia have a right planum temporale that is as large as the one on the left. Overabundance of language substrate on the left planum temporale.
What contribution to language did Penfield make?
Used awake patients and mild electric stimulus to get aphasic arrest and vocalization and speech arrest.
What did Ogemann do in language?
Used modern imaging techniques to expand on the Wada procedure. Stimulated fine points on the brain and observed different language disorder symptoms based on where he stimulated. These were in seemingly random and non-clustered locations.
What is the degree of involvement of both hemispheres in language processing?
Both hemispheres are involved heavily in language processing, except in split brain patients.