Neural basis of language Flashcards
Where is Broca’s area? Lobe and Hemisphere?
Left, prefrontal areas - part of inferior frontal gyrus
Who was Broca’s patient called and why?
Patient Tan: he could only say one word, “tan”
Where is Wernicke’s area?
left temporal lobe
Where did Ludwig Lichtheim (1880s) find lesions in his patients who had impairments repeating words?
lesion in the area that connects Broca’s and Wernicke’s area -articula fascius
Norman Geschwind (1960s) model said what about different brain areas?
The model described different areas playing different roles: Language network involving multiple areas
Comprehension extracted in Wernicke
Transferred to Broca’s
Broca translates it into speech
Importance of arcuate fasciculus for transfer of information from comprehension to production
Which hemisphere dominates for language in most right handed people?
Left
What is alexia?
Alexia is a term describing a partial or complete inability to read.
What is agraphia?
Agraphia is an impairment or loss of a previous ability to write.
The 3 types of fluent aphasia?
Fluent: speech production is fluent but there are problems in speech comprehension
Wernicke’s aphasia
Conduction aphasia
Transcortical sensory (isolation)
The 3 types of non-fluent aphasia?
Non-fluent: speech comprehension is spared, but speech production is non-fluent.
Broca’s aphasia
Global aphasia
Transcortical motor
Characteristics of Broca’s aphasia?
Difficulty in planning and organising spontaneous speech (effortful speech), motor planning of the articulation, associated with paralysis of the right upper limb and buccofacial apraxia, Telegraphic speech due to agrammatism, Patients show fewer difficulties when they are not required to spontaneously initiate speech (e.g., recognising correct vs incorrect sentences), Repetition might be less impaired than spontaneous speech, but still poor.
What is agrammatism?
difficulties in using syntax to determine the relationships between words (subject-object)
What is buccofacial apraxia?
difficulty in moving mouth and face
Characteristics of Wernicke’s Aphasia (fluent)?
Difficulty in auditory comprehension
Difficulty in repeating back
Patients hear sounds but are not able to attach meaning to them
Production of language is spared (fluent aphasia), however speech does not make sense -> Semantic impairment
Use of neologisms (newly coined words or expressions) – jargon aphasia
Patients can be oblivious to their errors
What is a neologism?
neologisms (newly coined words or expressions)
What is the arcuate fasciculus and which aphasia where there’s a lesion here?
arcuate fasciculus = white matter pathways that connect Broca’s and Wernicke’s areas Conduction Aphasia (fluent)
Characteristics of conduction aphasia (fluent)?
Problem with repetition
Some problems with production
Unlike some of Wernicke’s aphasic patients, they can monitor their speech (aware of their errors)
Conduit d’approche: after a few attempts, patients produce the right word -> reveals preserved knowledge of how the word should sound
Good comprehension
The 2 types of Transcortical aphasias?
Transcortical Sensory Aphasia (TCSA) (fluent)
Transcortical Motor Aphasia (TCMA) (non-fluent)
What are both types of transcortical aphasia characterised by?
intact repetition
3 characteristics of Transcortical Sensory Aphasia (TCSA) (fluent)?
Disorder of comprehension
Production is filled with neologisms
Lesions near junction of temporal, parietal and occipital lobes
3 characteristics of Transcortical Motor Aphasia (TCMA) (non-fluent)?
Difficulties in initiating speech
Good comprehension
Generally associated with dorsolateral prefrontal regions, often overlap with Broca’s area
The dorsal pathway in the language network is mostly associated with what?
production and articulation of speech
The ventral pathway in the language network is mostly associated with what?
comprehension and semantics
The language network is in ________ hemisphere and information flows from temporal to ______ cortex (dorsal) (then back again - ventral).
Left hemisphere
Information flow from temporal to frontal cortex
Dorsal pathway (arcuate fasciculus): \_\_\_\_ -to-motor mapping. Important for speech \_\_\_\_\_\_\_.
Auditory-to-motor mapping.
Important for speech repetition (arcuate fasciculus, remember conduction aphasia)
Which pathway is the superior temporal gyrus and what is it involved in?
Dorsal pathway
Involved in auditory processing, including language
What is syntactic structure?
The grammatical function or meaning of a sentence
Ventral Pathway: used for _______ processes at word-level.
Such as ______ , _______ at ______ level.
Simple syntactic processes.
Semantic processes at word-level such as semantic judgments and semantic plausibility at sentence-level.
EEG - negative is plotted upward or downward?
upward
Event related potential N400: involved in ______ processing
Kutas and Hilyard, 1980
N400: involved in semantic processing
What is an event related potential?
The measured brain response that is the direct result of a specific sensory, cognitive, or motor event.
ERP - N400 is involved in _____ processing.
Kutas
N400 is involved in semantic processing.
Semantically unexpected words produce a _____ in the signal of N___ EEG around ____ ms after the word.
Semantically unexpected words produce a decrease in the signal of N400 EEG around 400ms after the word.
What does LAN stand for?
Left Anterior Negativity
What is LAN involved in detecting?
LAN (left anterior negativity): involved in detecting a syntactic irregularity.
E.g. she was writing ‘books’ instead of ‘book’
In LAN, (syntactic) violations produce a ____ in the EEG signal around ___ms after stimulus onset (note: negative is upward).
In LAN, (syntactic) violations produce a decrease in the EEG signal around 500ms after stimulus onset (note: negative is upward).
What does ELAN stand for?
Following stimulus presentation, how many ms is ELAN observed?
Early Left Anterior Negativity
150 - 250 ms
P600 is involved in ________ a word into ________.
Primarily thought of as the _____ component.
P600: involved in integrating a word into the preceding context, primarily thought of as a syntactic component.
Can P600 sometimes be found outside of language?
Yes
(_______) unexpected stimulus in a series of events produces an increase in the P600 EEG signal ____ms after stimulus onset.
(Syntactically) unexpected stimulus in a series of events produces an increase in the EEG signal 600-800ms after stimulus onset.
N400: primarily a _____ ERP
LAN/ELAN and P600: primarily _____ ERPs
N400: primarily a semantic ERP
LAN/ELAN: primarily a syntactic ERP
P600: primarily a syntactic ERP
P600 has also been found in ______. And in ______.
Patel
Music, and in the right hemisphere version: ERAN
Friederici set out 4 stages of language development:
Phonemes discrimination and prosody - ______ days
Inventory of phonemes and stress pattern - ____ months
First word production: _____ months
Syntactic Structure and acquisition: _____ years
Phonemes discrimination and prosody - a few days after birth
Inventory of phonemes and stress pattern - by 9 months
First word production: 11 - 13 months
Syntactic Structure and acquisition: 2 - 3 years
Pena et al. (2003) study: Does the brain respond specifically to language stimuli from birth?
12 newborn infants took part in the study (2-5 days old)
Level of ______ in the brain was used to measure extent of processing language stimuli.
Newborns can differentiate between speech and non-speech.
Found ______ activation for _____ speech vs. ______ or _____ speech.
Newborns showed increased activation in the _____-hemisphere
Level of haemoglobin in the brain was used to measure extent of processing language stimuli.
Newborns can differentiate between speech and non-speech
Specifically, they found increased activation for normal speech vs. silence or backwards speech
Newborns showed increased activation in the left-hemisphere
Gervain et al (2008) study - 22 newborns
NIRS (near - ___ spectroscopy) used to detect brain activation for repetition of syllables
Repeated syllables: ABB (e.g., “mubaba”, “penana”)
Random syllables: ABC (e.g., “mubage”, “penaku”)
Non-adjacent repeated syllables: ABA (e.g., “bamuba”, “napena”)
Left _____ and _____ areas respond more to adjacent repeated syllables (ABB) than to ABC and ABA
Neonatal brain is able to detect certain ____ in language input, which may support language development and learning
Near - infrared
Left temporal and frontal areas respond more to adjacent repeated syllables (ABB) than to ABC and ABA
Conclusion: Neonatal brain is able to detect certain regularities in language input, which may support language development and learning
By _____ months: babies can associate novel words to objects, but not remember the association the day after (Friedrich & Friederici, 2015)
3
By ______: babies are able to discriminate familiar and unfamiliar words (Thierry et al., 2003; Mills et al., 2004)
the end of first year
By _______:
_____-like effect observed when presented with incongruous picture-word pairs (Friedrich & Friederici, 2004)
Can detect ______ errors (e.g., “the cat drinks the ball/milk”), but they take longer compared to adults (600ms-1200ms compared to 300-800ms)
One year and a half
N400
Semantic errors
In children (__ - __ years old) the syntactic event-related components start to develop (e.g. ____, ____)
2 - 4 years
P600 & LAN
What is Developmental Dyslexia?
Developmental disorder that affects the domain of language processing, with unaffected intelligence, affective processes and auditory abilities.
According to Friederici, 2004, Children at (genetic) risk of developmental dyslexia show decreased responses in ______, ______, and ______ processing.
Phonological, semantic and syntactic processing
