Chapter 11 Flashcards
Language?
-using syntax to communicate and convey meaning
Animals have complex communication system, but not language.
You need to use words and grammar syntax to have ability to create new meaning
Mental lexicon?
What does the mental lexicon store?
dictionary of words, their meanings, and grammar rules, in both hemisphere storing:
-semantic info (meaning of words)
-syntactic info (how words are combined to create new meaning)
-word forms: orthographic (visual: written word, what it looks like on paper) and phonological (how a word sounds like when spoken ex: aaron vs. erin) structure of words. We need mental lexicon for both speech and comprehension
semantic network mental model
The words in the mental lexicon are represented as conceptual nodes, which connect with each other. For example, the node that represents the word car will be close to and have a strong connection with the node that represents the word truck. Words that have strong associative or semantic relations are closer together in the network (e.g., car and truck) than are words that have no such relation (e.g., car and clouds).
How conceptual knowledge is represented in semantic network?
Some propose that words that co-occur in our language prime each other (e.g., cottage and cheese), and others suggest that concepts are represented by their semantic features or semantic properties. For example, the word dog has several semantic features, such as “is animate,” “has four legs,” and “barks,” and these features are represented in the conceptual network.
Semantic priming effect
People respond faster to an item presented if they saw an item before with similar meaning
(ex: seeing the word rose as a primer, then saying the target word: flower)
Semantic paraphasia
An error in speech in which one word is substituted for another word that is similar in meaning
- A person means to use one word, but they use another wrong word (say fork instead of spoon, when you meant spoon), the word is usually conceptually related in category
category-specific anomia?
person can describe the object within a category in detail, but has trouble to retrieve (recall) the name.
“I know this thing, but I can’t recall a name”
Physical vs. Functional Properties theory for category-specific anomia (Warrington)
theory states that it’s necessary to have the visual association with the word. For example, you associate the animal kangaroo with pouch (marsupial), the loss of which can be difficult to retrieve the word kangaroo (physical properties). But for the objects, such as comb, we have both: visual and sensory motor associations (functional properties). If you damage one area of the brain, the associations may still exist
Fundamental Categorical Organization theory for category-specific anomia (Caramazza)
His theory states that mental lexicon is thoroughly organized into categories, which correspond to specific areas of the brain. For example, people will have a trouble naming animals, when they get inferior temporal lobe damage, located anteriorly in the brain. If they will get a lesion further back: in posterior part of the brain, they will have difficulties naming tools. Whereas the damage to temporal pole will disrupt the ability to name people.
Complexity of Features theory for category-specific anomia (Tyler)
The theory is more focused on shared features of the word. It makes a distinction between the words at specific level (e.g., zebra or pencil), which requires additional features and the domain-general level (e.g., living or nonliving), which only needs a subset of features to name the picture. In addition, the living things are more difficult to recognize, because they share more features in comparison with nonliving things. As a result, if you have a damage to mental lexicon, you will still be able to activate the nonliving word (e.g., wood and lead for pencil). But you will not name a living word: zebra with damaged semantic network of mental lexicon, since you will have trouble to activate all association words, such as black and white stripes.
Top-down vs bottom-up processing (Language comprehension)?
Language comprehension model starts with input and ends up with conceptual representation (spoken or visual language)
-A mix of top-down (complex to simple) and bottom-up (simple to complex) processing.
Bottom-up - based on raw data: the idea that we perceive the word and then look for the word in our mental lexicon
Top-down - allow info in mental lexicon to influence the analysis of the incoming info: our knowledge of words and grammar can influence our visual and auditory perception
Segmentation Problem?
using knowledge in our mental lexicon to influence what we hear (our perception)
An issue of speech perception by sonograph
- how do you know that “do you mean” is 3 words and not one big word
Cap-tain – looks like 2 words;
testing – like 2 words on sonograph
Spreading activation
you mentally activate a word, when you think about it, which spreads to the connections, activating associative words. For example, you think about red and flower - you activate rose.
Language Comprehension, is it top-down or bottom-up processing?
Top-down influence, it affects auditory processing as well - you don’t know words of a doctor, but pharmacist can recognize them.
Top-down processing – perceives letters different, bottom-up perceive letters the same.
Brain areas and speech comprehension (Which part of brain?)
-some areas are very sensitive to phonological/acoustic properties (ex: high vs. low voices), but language sensitivity is very low (during early areas, red spot auditory cortex)
-high acoustic sensitivity in the primary auditory cortex (red spot); (sounds are treated the same as any sound)
-high language sensitivity in superior temporal sulcus ,
Speech comprehension – inferior left frontal lobe areas. Blue areas are the opposite of red
Brain areas and speech perception.
Where does the brain start treating language information differently?
The superior temporal sulcus - evidence that brain is responding differently to language sounds vs non-language sounds (sounds become treated like language); The Broca’s area (frontal lobe) is more sensitive to language rather than acoustics. Broca’s is involved in some aspects of comprehension, but it’s more about production of language.
N400 ERP response?
negative deflection if semantic content is wrong (semantic violations)
(ex: He spread the warm bread with socks - semantically wrong)
-someone with wernicke’s aphasia may find it difficult to comprehend
N400 (400 ms) - language comprehension, reflecting about semantic processing; it can be a surprise, unexpected response.
P600 ERP response?
a positive (P600) ERP shift following a syntactic violation in a sentence (grammatically incorrect)
Issue with grammar (syntax);
P600 it’s more about syntactic violations of language; you wouldn’t get P600 if you don’t know the grammar of language
ERP’s and language deficits
N400 response still occurs in people w/ language deficits (comprehension) but it is reduced and delay
*suggests that language disorders are an issue of timing (delayed)
How is the lexical, grammatical, and phonological model of speech production supported? Which phases?
ECoG recording – Broca’s area frontal lobe
ECoG recordings found that
1st phase: using less common words = larger response than common words
2nd phase: reading words on a screen = smaller response, but choosing correct morpheme version of word changes response = suggests grammatical change
3rd phase: words with more syllables= larger response
How is the lexical, grammatical, and phonological model of speech production supported?
ECoG recording – Broca’s area frontal lobe
Broca’s (Expressive) aphasia? Symptoms? Leborgne case? Which part of brain?
-non-fluent telegraphic speech (leaving out connecting words; ex: hands…tingling…stroke…reading)
-trouble making sounds/controlling muscles to make sound
-normal comprehension, but agrammatism (difficult comprehending more complicated sentences)
ex. Leborgne lost ability to speak, but he could make sounds; paralysis on right side; he was intellectually aware. Huge lesion in the left-inferior temporal lobe, localized in left-hemisphere.
We speak with the left hemisphere from French.
Which part of brain lesion? (Broca’s aphasia)
Left inferior temporal lobe – Broca’s area in left hemisphere (cortical area, outside);
Broca’s aphasia produce not only Broca’s area
AND deeper damage to underlying structures (insular cortex damage)
Wernicke’s (receptive) aphasia? What are symptoms?
person has fluent speech BUT makes many errors in speech and uses incorrect words (semantic paraphasia)
EX: I called my mother on the television”
-person is unaware of errors
***issue with self-monitoring and turning thoughts to words
No trouble with producing speech, but more comprehension;
