8: The Speaking Brain 2 Flashcards
define: syntax
the arrangement of words and phrases to create well-formed sentences in a language.
what element of speech is used to formulate communicative intentions?
semantics
what component of speech is used to construct sentences?
syntax
what component of speech is used to select lexical semantics?
word retrieval
what component of speech is used to retrieve phonological code?
working memory
what is phonological code?
how we know how to make the sounds that we need for speech
a lesion in which area of the brain leads to problems with syntax?
broca’s area
broca’s aphasia is causes problems with what component of speech production?
syntax -loss of grammar
problems with articulation are as a result of which 2 conditions?
dysarthria & apraxia of speech
dysarthria & apraxia of speech are problems which with component of speech production?
articulation
logopenic aphasia is associated with problems in what component of speech production?
working memory
problems with working memory are associated with what condition in speech production?
logopenic aphasia
problems in wernike’s area lead to problems with which 2 components of speech production?
semantics & word retrieval
problems with semantics & word retrieval can be caused by damage to what area of the brain?
wernicke’s
what are the 3 stages of word retrieval
lexilisation
↓ = stage 1
lemma
↓ = stage 2
lexeme
define: lexilisation
Selecting a word based on the meaning one wants to convey
define: lemma
The word-level information that specifies the syntactic components of a word
define: lexeme
The phonological code that drives articulation
what happens during the lemma stage of speech production?
Retrieving and specifying the grammatical properties of the word
what happens during the lexeme stage of speech production?
Retrieving the phonological patterns needed to articulate the word
what is an example of a lexicalization issue
Freudian slip
what are 3 examples of issues with lexemes (phoneme-level errors)
tip of the tongue phenomenon
spoonerisms
malapropisms
define: spoonerism
the initial consonants are swapped between words (pells & bepsi)
define: malapropisms
saying a word with a similar phonological form to the intended word (eg for all intensive purposes vs for all intents and purposes)
how do homophone grammar mistakes provide evidence for levelt’s model of word retrieval?
we very rarely make mistakes where we use the homophone in the wrong grammatical setting - suggesting we retrieve the correct grammar (lemma) before we retrieve the lexeme
how does the tip-of-the-tongue phenomenon provide evidence for levelt’s model of word retrieval?
we know the lexicalization (meaning) & lemma (grammar), just can’t retrieve the lexeme
what are mixed errors of speech production?
Speech errors where the intended word and produced word are similar semantically and phonologically?
eg Saying “rat” when you meant “cat”? “Oyster” for “lobster”
how does the tip-of-the-tongue phenomenon provide criticisms of levelt’s model of speech production?
sometimes we know the first letter of a word we need, cannot explain the phonological retrieval of the word when we don’t know it in full yet
what is teh distinctive difference between levelt’s & dell’s models of lexilisation
levelt = only moves in 1 direction through the stages
dell = interactive between layers, all levels of processing active simultaneously with election
of the “winning” word retrieved arising via a competitive process
what does it mean to say dell’s model of speech production is competitive?
- stimuli triggers ‘activation’ of ‘nodes’ at different layers
- How ‘active’ nodes become is based on the ‘weighting’ of their connections
- ‘Activation’ spreads based on ‘weighting’ until a pattern of ‘nodes’ exceeds a threshold
- The word represented by the ‘winning’ pattern will be ‘retrieved’
how does dell’s model of speech production explain mixed speech errors?
- Activation simultaneously at the semantic and phonological layers - high activation = speech
- The produced word is both phonologically and semantically similar (“oyster” for “lobster”
how does dell’s model of speech production explain mixed speech errors?
- Activation at the phonological layer
but a word hasn’t ‘won’ the competition yet: - T-o-T phenomenon whilst knowing it starts with a certain phoneme
what characterises speech for someone with logopenic aphasia?
- Speech characterised by word-finding impairment and phonological speech
errors (phonemic paraphasias) - But semantic memory is normal
how does dell’s model of speech production explain logopenic aphasia
this pattern of impairment with issues with the phonological-lexical layer, with intact semantic-lexical layer
what are the 3 layers in dell’s model of speech production?
semantic, words, phonemes
what condition is logopenic aphasia associated with?
alzheimers
people with logopenic aphasia often have atrophy in what part of the brain?
left posterior temporal cortex
what are the levels of the SLAM mode of speech production?
semantic -> lexical -> auditory -> motor
what parts of the brain are associated with each stage of the SLAM model of speech production?
semantic = temporal lobes
lexical = auditory cortex
auditory = inferior parietal cortex
motor = frontal cortex
what neuroanatomical model is the SLAM model of speech production based on?
duel stream model of speech
what are the 2 streams in the dual stream model of speech?
dorsal & ventral
what does the dorsal stream in the dual stream model of speech do?
speech production (motor)
how is info passed through the brain in the dorsal stream for speech production?
Auditory information is passed through the parietal lobe to the inferior frontal gyrus and motor cortex
what does the ventral stream in the dual stream model of speech do?
speech comprehension (semantics)
how is info passed through the brain in the ventral stream for speech production?
Auditory information is passed through temporal cortex to temporal pole for comprehension (semantic knowledge)
when would just the dorsal stream of speech production be used?
when you’re repeating someone else (no need to decide what to say)
where is the dorsal stream of activity in the brain for speech repetition?
superior temporal gyrus -> broca’s area -> motor cortex
how does the order of brain areas for the ventral & dorsal streams of speech production compare to each other?
we first use the ventral stream in reverse followed by the dorsal stream
Temporal lobes → Auditory cortex → inferior parietal cortex → frontal cortex
define: parsing
assigning a syntactic structure to words
what moderates the activity in broca’s area?
syntactic complexity - the higher the complexity the greater the activity
what are the 2 competing explanations for parsing’s mechanisms?
structure driven vs discourse driven
what is the structure driven explanation for parsing?
based only on syntactic properties - syntax separate from semantics
what is the discourse driven explanation for parsing?
influenced by semantic properties of words
* semantics integrated with syntactic processing
define: garden path sentences
A sentence in which the early part biases a syntactic interpretation (that turns out to be incorrect)
what does the N400-P600 distinction tell us about syntax and semantics?
N400 only for semantic anomalies
P600 only for syntactic anomalies
- shows distinction of semantic from syntax in the brain
how does logopenic aphasia evidence the separation of syntax and working memory
their syntax is fine they just can’t repeat long sentences cause their working memory is bad
what are the different roles of the anterior and posterior parts of broca’s area?
posterior = processing hierarchical structures and sequencing
anterior = working memory and semantic control
define: articulation
The formation of clear and distinct sounds in speech
define: syllabification
The process of segmenting phonological information into syllables across adjacent morphemes and adjacent words
what parts of the brain are associated with phoneme level articulation?
motor area,
pallidum (basal ganglia),
posterior superior temporal gyrus
what parts of the brain are associated with syllable level articulation?
ventral premotor cortex
apraxia is associated with damage to what area of the brain?
insula
what characterises apraxia of speech?
Difficulty shaping the vocal tract
what characterises dysarthria?
Impairment in muscular contractions of articulators
dysarthria is associated with damage to which areas of the brain?
cerebellum & basal ganglia
what kind of models are seen as the future of cognitive neuroscience?
Neuroanatomically-constrained computational models
if you stimulate the left inferior parietal areas of the brain, how does this influence speech production?
led participants to believe they had moved their lips to talk
if you stimulate the premotor region of the brain, how does this influence speech production?
triggers mouth movements that participants were not conscious of
