Language Flashcards
What is unique about human language?
What is the structure of language?
Syntax! Phonemes: sounds Morphemes: small units of words Lexicon: vocabulary Syntax: rules of grammar Semantics: meanings that correspond to vocabulary Prosody: rhythm and tone of voice Discourse: stringing sentences together to form a story
What has been sucessful in chimpanzee studies for learning?
Yerkish and ASL
Chimps can learn BASIC stuff
“banana give me”
Whos is Alex the Parrot?
Showed cognitive and comprehension (plate task, differentiate number and shape of objects.
The ‘banary” shows he is extrapolating knowledge!
What are areas associated with Aphasia?
Broca’s area: patient ‘Tan’ who could understand, but couldn’t produce
Wernickes: no comprehension, fluent speakers but ‘word salad’. Syntactially correct, but nonsensical.
Arcuate Fasiculus: connecting brocas and wernicke’s areas, white matter tract. If this is damaged, you see impairments.
Prefrontal (motor and planning motor)
Further back is for sensory.
The brain isn’t just ‘wernicke and broca’ its much more diverse.
Where is lexicon stored?
Vocabulary!
Often stored in the visual areas, end of the ‘visual’ stream, which is the VENTRAL STREAM.
the “what” pathway.
Area that stores imagery for an animal also stores the WORD for that animal.
Next to broca’s area.
Selecting COMPETING WORDS (teapot vs. kettle) is in prefrontal cortex.
Speech is in motor control also
who was wilder penfield and what did he do?
Identified and mapped neocortical language zones during surgery.
Was trying to find the focus of epilepsy but mapped brain while doing so.
Gently stimulated the cortex, and in pre-motor areas, this caused problem with speaking, confusion when counting.
- total arrest of speech
- hesitation or slurring
- distortion and repetition
- confusing counting
- difficulty naming things
- misnaming and perseveration
applies to modern stimulation too
What is the Wernicke Geschwind model?
What are it’s shortcomings?
Info comes through auditory cortex, moves ONE WAY through Wernickes area where comprehension is extracted, goes through arcuate fasiculus, and goes to brocas area to be articulated as speech.
Brocas areas sends into to motor cortex for speech.
(for reading, visual areas send into to angular gyrus)
Shortcomings:
- doesn’t take into account other brain regions
- simplistic view or regions and directionality of flow
- relies on loss of function studies
- the ‘areas’ aren’t even real areas, theyre many many subregions
How is brocas area organized?
Dorsal and ventral organization. There are mirror neurons, and martial mortor cortex sitting on top each other.
Dorsal/posterior: how you speak, phonological processsing and production of words
Ventral/anterior regions: meaninfulness of words, semantics
Same ventral/dorsal organization for wernikes too! (ventral semantics, dorsal production)
What is the Dual language pathway?
Where is flow of into targetted to usually?
Birectional! Ventral vs Dorsal not Wernicke vs Broca!
Ventral: top down, long term memory, semantics. Understanding/meaninfulness, separating homonyms
Dorsal: bottom up, short term memory, phonetics, speech production. When someone is asked to repeat nonsense words this is the only pathway used
Area 6: motor cortex
Area 47: sematnics are targets to flow of info
What are the types of aphasias?
Fluent: able to talk with impairments to comprehension . word salad. Proper words strung together randomly, cannont discern phonetic charictaristics.
damage to wernickes area or the ventral stream
- two types of fluent aphasia
i. conduction aphasia, can speak and understand but cannot repeat words (problem is disconnection between perceptual word image and motor systems to produce the word)
ii. anomic/amnesic aphasia. difficulty naming objects, can comprehend and produce meaningful speech and can repeat, but can’t use vocab well (get confused, even say the word in a sentence and can’t understand)
non-fluent. in tact comprehension and response, but production damaged. trouble speaking.
- broca’s aphasia (with comprehension) or global aphasias (poor comprehension too)
What is dyslexia and agraphia?
dyslex and alexia: problem reading
agraphia: problem writing
Whats transcortial aphasia?
isolation syndrome.
Can repeat isolate words but cannot speak spontantously and often have poor comprehension.
Why is studying neural basis of language complex?
Most of the brain takes part in language
Most patients who add info to studies have had strokes
Immediately after a stroke symptoms are severge but improve as time passes
Aphasia syndromes have many varied symptoms each with different causes.
What are the cortical language components of nonfluent aphasia?
Dorsal pathways. (studied in overlay plots)
- damage in insula (resulting in apraxia)
- damage to superior temporal gyrus (auditory cortex) which results in lack of comprehension.
- damage to arcuate fasiculus results in repetition of speech
- damage to broca’s area results in working memory and articulation impairment.
Automatic/immediate well learned info can still be in tact (alphabet, counting)
“tonno man”
What are cortical language components of fluent aphasia?
Ventral pathways
- Wernickes area
Lack of speech comprehension and other core difficulties with language due to damage to
- medial temporal cortex and white matter
temporal cortex results in holding sentences until they can be repeated.
Lack of speech comprehension- damage to deeper areas too not just auditory and wernickes (hippocampus, amydgala)
