ANAT3022-Language-Speech-2024 Flashcards
What is language comprehension?
Linguistic signals are decoded and combined with linguistic and non-linguistic signals (e.g., Linguistic encoding and decoding & Semantic and pragmatic embedding)
What is language production?
Meaning, abstract ideas or thoughts are being linguistically encoded and sensormotorically represented (e.g., Sensmotoric representation)
What are the components of linguistics? Provide examples of each.
Phonology
-smallest units of sound, phonemes
-speech /spiːtʃ/ - /s/ /p/ /iː/ /tʃ/
Morphology
-smallest units of meaning, morphemes
-hat, brain, language, etc
Syntax
-combination of meaningful units to sentences
-SUBJECT + VERB + OBJECT
- The cat climbs the tree.
Semantics
-ways in which a language conveys meaning
-“having cold feet”
Pragmatics
- how members of a speech community achieve goals using language
-political speech vs five friends
-Talking over lunch
What are some of the reasons why animals communicate?
- Mating
- Foraging
- Threat
- Territory
- Protection
- Affection
Do apes learn speech?
- Chimps generate 2-word utterances after extensive training
From what age do children begin to learn simple sentences?
- Children learn uttering 3-4 word sentences within the first 4 years
Over what period of development is childrens steepest vocabulary and grammatical growth?
- Steepest vocalbulary and grammatical growth between 18 months to 7 years
How do babies they learn speech?
- Without training, through social interaction (e.g., language shaped through social environment!
How do neo-nates react to language? And what does this suggest about humans language capacities genetically speaking?
- From birth the brain reacts more strongly to speech than other to auditory input which is represented by Echo-planar imaging (EPI) scans showing increased activity in the primary and secondary cortex of 2 day old babies
- → Biological advantage for acquiring language
Do neo-natals (1-28days old) cry in their mother tongue in terms of phonetic structure? What is this evidenced by and what are the implications for these findings?
- Yes, Cries of neonates are language-specific
- Evidenced by comparing the cries of 2-5 day old French and German babies. The French language stress the last syllable whereas German stresses the first and this structure is represented and reflected in the cries of the babies as according to their mother tongue (native language)
- The implications are that stress patterns are learned prior to birth
Do babies perceive phonetic rules? And what does this suggest about language development? And finally, what is the critical phase for language development?
- Yes, as according to EEG readings of brains of 4-5month infants a greater deflection (mismatch response) is shown when German babies are played deviant sounds, that is sounds that stress the last syllable (e.g., French language phonetic structure) compared to when they are played standard sounds according to the phonetic structure of their native language (e.g., German stressing the first syllable)
- Linguistic environment determines neuronal correlates
- → Processing advantage for mother tongue, with a critical phase in the first 12 months
Do babies know grammatical rules? How is this evidenced?
- Yes complex rules – insertion – are learned and violations are neurally represented.
- As according to EEG readings of brains of 4-5month infants a deflection (mismatch response) is shown when played audio recordings of sentences that had insertions which violated grammatical rules.
What is Broca’s aphasia in terms of functional impairment? What fibre connection was damaged between brocas area and other relevant language processing areas of the brain?
- Motor, verbale, grammatical speech disorder, with (mainly) intact comprehension
- Damaged fibre connections: Superior longitudinal fasciculus & arcuate fasiculus
In terms of syntactic language processing in the IFG (Broca’s area) how is neuronal signal represented according to EPI scans?
- Neuronal signal in the inferior frontal gyrus is modulated through grammatical complexity (e.g., higher complexity of syntax/ sentence structure = higher signal/ more activity)
What is fluent aphasia?
- A type of aphasia (language disorder after stroke) with poor comprehension, but speech is effortless and the meaning is impaired
What is wernickes aphasia? And how is it related to fluent aphasia?
- Wernicke aphasia: Relative fluent speech with anomia (unable to recall names of everyday objects) and poor comprehension.
- Wernicke’s aphasia is a specific type of fluent aphasia. It occurs due to damage to Wernicke’s area (posterior superior temporal gyrus).
- Fluent aphasia describes a broader category of language disorders where speech is fluid or well-formed, but the person’s ability to convey meaningful content is impaired
What brain areas are activated and responsible for semantic speech processing?
- Superior temporal gyrus (STG), angular gyrus (AG), medial temporal gyrus (MTG)
- When comparing EPI scans measuring brain activity when exposed to congruent vs incongruent (jabberwocky) sentences neuronal signal in the temporal and angular gyrus (Wernicke area) represents an area for semantic processing
- integration of visual, auditory, and linguistic information)
What brain regions make up the speech network? Is there a dominant hemisphere? Are these activation maps stable over time?
- Inferior Frontal Gyrus (IFG)
- Middle Frontal Gyrus (MFG)
- Posterior Temporal region
- Anterior Temporal region
- Inferior Front gyrus orbital
Is there a dominant hemisphere for language processes?
- Left hemisphere dominant however reviews suggest that on average there are still activations in the right hemisphere which illustrates individual differences.
What are important characteristics of the activation map in regards to the language network of the brain?
language network is:
- Selective
- individual (variable)
- temporally stable.
What are the three fibre tracts of the language network and what brain regions do they connect?
- Dorsal pathway: temporal cortex, STG (Wernicke’s area), via arcuate fasciculus and superior longitudinal fasciculus to IFG (Broca’s area)
- Dorsal Pathway temporal cortex via arcuate fasciculus and superior longitudinal fasciculus to the precentral gyrus, i.e., premotor cortex
- Ventral pathway: ventral inferior frontal gyrus via extreme capsule to temporal cortex
Is there a difference between adults and newborns in terms of language networks of the brain?
- Newborns do not have the 1st dorsal pathway connecting STG (Wernicke’s area), via arcuate fasciculus and superior longitudinal fasciculus to IFG (Broca’s area) which is functionally represented and understood by babies not being able to produce speech.
What do MEG-recordings of language processing suggest about syntactic and semantic processing?
- When comparing auditory and visual language processing it demonstrates a simultaneous activation of relevant brain regions which suggests simultaneous processing of syntactic and semantic information
- Neuronal signal in the inferior frontal gyrus and temporal gyrus represents syntactic and semantic processing similarly
And what brain regions are involved in syntactic and semantic language processes?
ATL: Anterior temporal lobe,
PTL: Posterior temporal lobe,
TPJ: Temporoparietal junction
Why is the language network of the brain important in terms of overall functionality?
- Although the different processing areas of the brain are fairly non-specific the overall network is highly specific and requires all regions in totality for normal language functions (parallel processes)
What is the left hemisphere and right hemisphere of the brain responsible for functionally (processing language)?
- Left hemisphere: Language dominance
- Right hemisphere: prosody, emotional tone, and understanding figurative language
What is the link between symptoms of schizophrenia and how they are related to language alterations?
Positive symptoms:
- Auditory verbal hallucinations
- Formation of delusions (related to language
Cognitive symptoms:
- Impairments in Language Processing
Negative symptoms:
- Alogia (poverty of speech)
- Social interaction
- Motivation
What is a formal thought disorder?
- Definition = severe language and speech disturbance specifically referring to disturbances in thought process rather than thought content.
What other psychiatric conditions are known to carry formal though disorder symptoms?
- 50-80% schizophrenia
- 60% Schizoaffective
- 53% Depression
- 6% general population
What are some of the examples of symptoms of a formal thought disorder?
- Derailment (loosening of associations)
(e.g., When asked about a symptom of breathlessness: I felt breathless, like running a marathon. Marathon, the ancient Greek town… Democracy today has gone wild, hasn’t it?’)
- Tangentiality (giving answers in an oblique fashion)
(e.g., When asked how they hurt their arm: ‘Well, I was riding my horse, and it was so sunny, but I suppose that is normal for this time of year. I prefer the summer months.’)
- Incoherence (‘word salad’, schizophasia)
(e.g., Glasses without a square battery mouse nor lacking table is the bottle and yes dancer’)
- Illogicality (drawing conclusions that do not follow basic logic)
(e.g., I was born on a Wednesday and today is a Wednesday so it will not rain today.’)
- Circumstantiality
(e.g., Excessive long-windedness in reaching a conclusion in answer to a question)
- Pressure of speech
(e.g., Increased production of spontaneous speech)
- Distractibility of speech
(e.g., The subject of conversation is changed in response to a stimulus: ‘I was
walking to the shops when… What is your favourite song?’)
- Clanging
(e.g., The sounds of words (such as their rhyming) dictates word choice: ‘I still live on the hill, and that’s quite a thrill, if you will.’)
What are differences in the connectivity of language networks of people with schizophrenia?
- specifically, the arcuate fasciculus and the superior longitudinal fasciculus which connect Wernicke’s and Broca’s area which are necessary for meaningful speech
- patients with schizophrenia show significantly reduced fasciculopathy (e.g., strength of which areas are connected). Reduced connectivity.
What does a predictive coding account suggest of patients with psychosis? And What brain regions are involved?
Brain uses prior knowledge to infer causes of incoming sensory data to construct a predictive model which is updated through prediction errors
- Psychosis patients demonstrate Impaired (reduced) prediction error processing through imbalanced weighting of the prior and the sensory likelihood
- VTA & PFC
How does the hierarchical level of confidence of prior beliefs influence the predictive coding account of language changes in psychosis?
In psychosis:
- Overweighting of sensory data at lower processing levels → delusions (e.g., can’t explain the sensory information and need a story to explain the phenomena)
- Overweighting of priors at higher processing levels → hallucinations
Language is intrinsically…..
- Predictive
What do the predictive language paradigm experiments suggest?
- Higher schizotypy is linked to a higher perceived clarity → Indirect sign of overweighting of the prior
- Higher schizotypy is linked to more task-based hallucinations (E.g., when a person perceives what they expect)
- With increasing schizotypy the prior weight moves away from the sensory evidence and towards the prior belief (e.g., Higher schizotypy is linked to overweighting of prior belief when context is unpredictable (with higher uncertainty))
What is the N400 effect?
- It is measured through EEG and it is the difference in amplitude take at 400ms between the control (low entropy) and other conditions (e.g., medium, high, low mismatch).
What do the N400 studies suggest?
- N400 amplitude is modulated by Entropy Condition → the more unpredictable the context the higher/more negative the amplitude → Prediction Error signal
- With increasing schizotypy, N400 amplitudes are smaller/more positive in High Entropy and Low Entropy Mismatch conditions
→ Smaller Prediction Error signal in unpredictable contexts in individuals with higher schizotypal traits
How are glutamate levels related to weighing priors in schizotypy? What brain region are they related to?
- Higher levels of glutamate in the ACC are associated with increased prior weight in those with higher schizotypy
Language: When comparing patients in different stages of psychosis (e.g., acute vs. remission) what are the differences in terms of perceived clarity and weighing of prior beliefs?
- In acute psychosis, higher positive symptoms linked to a higher perceived clarity (e.g., Similar with increased schizotypy) which is a Indirect sign of overweighting of the prior
- Effects seem to normalise during remission
Language: When comparing patients in different stages of psychosis (e.g., acute vs. remission) what are the differences in terms perceiving task based hallucinations (E.g., when a person perceives what they expect)?
- patients in acute psychosis perceive more task-based hallucinations than patients in remission (e.g., Similar with increased schizotypy)
Language - What does the quantified evidence for weighing of prior beliefs and levels of schizotypy suggest when comparing patients in different stages of psychosis (e.g., acute vs. remission)?
- Prior weight is shifted towards to prior beliefs with higher schizotypy, and during state of acute psychosis but normalised in state of remission
