Class 20 - Language Flashcards
Broca’s Aphasia
Speech production issue
Paul Broca
Non- fluent aphasia
words there wrong order missing prepositions/articles typically characterized with smooth/fluent speech
• Patients know what they want to say but have trouble saying it out loud
(Broca’s Aphasia) Poor speech quality:
- Limited amount of output
- Missing function words, word endings – telegraphic speech
- Has a hard time naming objects, repeating words
(Broca’s Aphasia) Not because the motor system is
impaired overall
• No problems with moving face or mouth muscles
• Can still produce non-linguistic sounds without difficulty
(Broca’s Aphasia) Comprehension is
(mostly) spared
(Broca’s Aphasia) Deficit of
programming speech output
Wernicke’s Area
- Speech comprehension
- Carl Wernicke
Wernicke’s aphasia
• fluent aphasia
Disrupted comprehension along with fluent production that doesn’t make sense
Broca’s Area
Speech production
Paul Broca
(Wernicke’s aphasia) Impaired
comprehension
• Sometimes have difficulty following simple commands
(Wernicke’s aphasia) Poor quality of
speech: lack of meaning
• No difficulty making speech sounds – motor functions intact • All parts of speech are present but together don’t make sense
(Wernicke’s aphasia) Paraphasia is __
errors in producing specific words
Semantic paraphasia: ‘barn’ for ‘house’ - main in WA
Phonemic paraphasia: ‘fable’ for ‘table’
Neologisms (plausible words not in lexicon): ‘paffle’
Phonemic paraphasia:
‘fable’ for ‘table’
Neologisms
(plausible words not in lexicon): ‘paffle’
(Wernicke’s aphasia) Deficit of
linking the sound image to meaning
Double dissociation
Determine whether two functions are independent
- Patient 1 has damage to area A, impaired function X, function Y is fine
- Patient 2 has damage to area B, impaired function Y, function X is fine
Double dissociation in Broca’s area
Damage to Broca’s area impairs speech production (X) but not comprehension (Y)
Double dissociation in Wernicke’s area
Damage to Wernicke’s area impairs speech comprehension (Y) but not production (X)
Syntactic and phonological processing in Broca’s aphasia
- Insensitive to grammatical markers (in this case, ‘by’)
- Uses basic subject-verb-object ordering instead
- Impaired at matching action with a picture
Syntactic and phonological deficits likely co-occur in Broca’s aphasics due to
large lesions that disturb neighbouring areas
Arcuate fasciculus
Connection between areas
Conduction aphasia, ___ is intact
Speech production and comprehension intact
Conduction aphasia, difficulty with ___
with repeating what was just heard
- Sound images (Wernicke’s) cannot be transmitted for production (Broca’s)
- Severed connection between the two areas – the arcuate fasciculus
- Often commits paraphasic errors (phonemic usually)
Disconnection syndrome:
no direct route between sound image and speech output areas
(In Conduction aphasia)
The posterior Language Areas in the L hemisphere
Typical of Wernkies apahasa - is posterer- and most people language is in the L hemisphere
Conduction aphasia, Often commits
paraphasic errors (phonemic usually)
Ventral stream (of Brain networks of speech)
link phonological and semantic information
Green - primary audory
yellow - phenotoghy prosessing
pink - ventral streem linking phnological to semantic
Blue - Semsimotor interface, articulation
Dorsal stream (of Brain networks of speech)
sensorimotor interface, articulation
Green - primary audory
yellow - phenotoghy prosessing
pink - ventral streem linking phnological to semantic
Blue - Semsimotor interface, articulation
Peole R handed language, speach represnted __
People L handed, language, speach represnted __
language on L hemisphere
also peope in left or mixed still majority L hemisphere
Split-brain patients have shown that the Right nemisphere can understand ___ but with deficits which are ___
spoken and written language
- Poor comprehension of complex syntax
- Cannot produce speech output
- Trouble processing abstract vocabulary
Right Hemisphere does contribute to processing in other ways
- Prosody (tone of speech)
- Narrative (following along with a story)
- Inference (filling in the blanks on something not explicitly said)
Prosody
tone of speech
N400 Seen with
violations of semantic expectancy (does that word match?)
Larger away from expected - larger response
negative response 400ms after “wrong” word
P600: Seen with
violations of syntactic expectancy - rules of language
- “The broker persuaded to sell the stock was…”: ‘persuaded’ is transitive
- “The broker hoped to sell the stock.”: ‘hoped’ is intransitive (expect sentence to end)
transitive
possability to continue sentence but does not continue
intransitive
sentece is complete/ended.
Semantic P600
seen in syntactically intact sentences with semantic anomalies
(expect to see N400 but is actully P600)
red - control sentence
blue - syntax is right (noun was verbing) but semanticly not make sence (meals do not do the devowering, they get devowered)
idea - mabey N400 actully has to do with tracing how words realted, concepts (so meals and devoring same concept
Lau & Namyst (2019)
Try to:
Used :
Comairason from two areas
Trying to locate where congruity and predictability (how much can we say what the second word is that is coming after the first word)
use FMR to localize where areas are (not as good with EEG)- might expect seprate anatomical areas for the two
Comaire FMRI and EEG data:
EEG- looking at difference in aplatude prectible ampltude large not predictable, small
fMRI - same with brain area
Lau & Namyst (2019)
We previously discussed semantic memory to be associated with anterior temporal gyrus. Given that semantics plays a role in predictability, why do we see more posterior middle temporal gyrus activity instead?
see MTG activity instead of because is the area focus on lexal processing (word level processing ) - thought to be where acessing indivdual words.
Lau & Namyst (2019)
Pradictability Manipulation and congruity manipulation
Lau & Namyst (2019)
The Wada test
‘Silencing’ one half of the brain: The procedure is called the Wada test and involves injection of a barbiturate into the bloodstream to temporarily inhibit activity from one hemisphere.
semantic vs syntactic
Syntax is the grammatical structure of the text,
whereas semantics is the meaning being conveyed
