Speech Production (1-3) Flashcards
What is a lemma
no form or pronunciation
you know the specific meaning of a word and maybe some grammatical features but not the word itself
Describe conceptual focusing
its the starting point of speech production
- thinking for speech (focusing on a concept)
- selection of perspective (talking about a chair to the right or left of you or the listener)
- theory of mind: ability to imagine the listeners knowledge
What’s a lemma model
its a feed forward system (one way)
it explains the process of thought to speech
lexical nodes bind together semantic features of concepts
What are the two parts of the lemma model
1) Lexical selection: focusing on a concept and picking a lemma (characteristics)
2) Form encoding: finding the phonological codes for the concept and mapping it onto a word for articulatory production
4 tasks involved in brain imaging studies for the lemma model
1) picture naming
2) associative word generation
3) word reading
4) pseudo word reading
all involve different processes and different parts of the lemma model
Conceptual focusing experiment
pic naming and word gen. in block condition vs. mix condition
anterior temporal region: nodes tying together features
high activation in left IFG (Broca) during block condition probably due to repetition priming (seeing the same stimulus in the mix condition)
Lemma Selection Experiment
Pic naming and word gen vs. word and pseudo word reading (driven by lemma selection vs. not)
left mid MTG activated (links phonological structure to semantic structure)
stimulation of MTG did not effect pic naming (output) but it did effect word comprehension (input)
Retrieval of morphemic phonological codes experiment
Pic naming and word gen, word reading vs. pseudo word reading- finding phonological codes
Left posterior STG/STS (Wernicke), MTG, left anterior insula and SMA activated
Prosodification and syllabification experiment
there’s syllabification in all 4 tasks
activated left post. IFG suggested to be involved in syllabification of a word
Phonetic encoding and articulation
see DIVA model
Self Monitoring
lemma model has 2 feedback loops
1) external: acoustic signal from own voice
2) internal: syllabification process
word production vs. word comprehension
-activation in posterior 2/3’s of bilateral temp. region for both loops
Is there really a lemma model for speech production
the model is not compatible to patients who have semantic errors in speech (but not in written speech)
SOLUTION: direct connection from semantics to phonological or orthographic representations = no lemmas
they remain controversial
Is there really a lemma model for speech production
the model is not compatible to patients who have semantic errors in speech (but not in written speech)
SOLUTION: direct connection from semantics to phonological or orthographic representations = no lemmas
they remain controversial
What’s the DIVA model
synthesized speech
model integrating speech science, computer science and cognitive science
tries to recreate human speech
What are the two components of DIVA
1) produces the sound (receives input and abstract word form is mapped to physical word form)
2) what we want to say (target) - checking to make sure what we said matches what we wanted to say
DIVA initiation maps
it kicks off the planned speech as it is being mapped out (how the commands can produce what you want to say)
Is DIVA a feedforward control system
yes
A speech sound map consists of
units of phonemes, syllables and chunked phrases
in Broca’s area
Apraxia of speech is cause from damage to the..
IFG (Broca’s aphasia or progressive non-fluent aphasia)
disorder of articulation planning
Units from the speech sound map inhibits or excites articulators?
excites (lips, tongue, palate etc.)
T/F, units in the speech map are organized somatotopically?
true, if they are physically beside each other, they are also represented beside each other in the motor cortex
spastic dysarthria
reduction of speech and range/accuracy of articulatory movements
damage to motor cortex bilaterally
Locked in condition and DIVA (implicated electrode in patients brain)
they can synthesize speech from a patient who could not speak… after an hour of training they could formulate vowels through DIVA
Ataxic dysarthria
slurred and poorly coordinated speech
Medial cerebellum damage (position map for articulators)
Ataxic dysarthria
slurred and poorly coordinated speech
Medial cerebellum damage (position map for articulators)
Initiation map (last component of DIVA)
module that sends the "go" signal to the prepared motor commands each unit of sound has a match on the initiation map, also on position map
Basal ganglia and SMA (supplementary motor area)
Damage to Basal ganglia
Parkinson’s disease
Damage to SMA
akinetic mutism (spontaneous speech and movement reduced)
Forward model of speech control
predicting how planned motor actions will feel
picking up something heavy vs. something light
Inverse model of speech control
prediction of the motor commands required to achieve a target state
hitting a bullseye with a dart
tends to be harder
Forward model in DIVA
speech sound map to auditory and somatosensory components of speech
expected and actual feedback from speech is compared in..
the auditory error map located in cerebellum
units of speech that correspond to expected feedback are…
inhibited by auditory target map
-units of sounds that should be there but are not
units of speech that correspond to actual feedback are…
excited by the auditory state map
-units of sounds that are there but shouldn’t be
describe the feedback control in DIVA
Auditory error map projects feedback which sends corrective commands to articulator velocity and position maps (aka. motor commands)
What happens to patients with schizophrenia when they have auditory hallucinations
there is a disconnection in the feedback system so they can’t distinguish the effects of self generated activation of sound and external context
during hallucinations the auditory cortex is most active and the frontal temporal network doesn’t seem to work properly
