Language II

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Language II

• October 25, 2007

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Speech/Language Production I

• Common Features of Models
• extensive pre-planning
• distinct stages of processing
• general (intended meaning)-to-specific
  (utterance) organization
• most models use of speech errors as data

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Spreading Activation Theory (Dell)

• four levels of activity
• Semantic (meaning)
• Syntactic (grammatical structure of words in the
  planned sentence)
• Morphological (basic units of meaning or word
  forms)
• Phonological (sounds)
• representation formed at each level
• processing occurs simultaneously at all levels
• uses speech errors as primary data

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Spreading Activation (contd)

• Lexicon connectionist network containing nodes
  for concepts, words, morphemes, and phonemes
• Insertion rules (which is highest activated?)
  determine items selected for insertion into
  sentences
• Errors predicted by model
• Errors more likely when speaker has not formed c
  coherent speech plan
• Errors should be from same category
• Anticipation errors (because of multiple
  activations The sky is in the sky)
• Exchange errors (because once selected, items
  activation turns to zero (I hit the bat with my
  ball)

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Speech Production II

• Levelt/Bock approach
• four stages message, functional processing,
  positional processing, and phonological encoding
• information about syntax (lemma) available before
  sound (lexeme)
• consistent with TOT phenomenon

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Bock Levelt (1984)
ERRORS
Intended meaning
Semantic substitution (tennis bat), blending
(sky is shining), word-exchange errors (let
the house out of the cat)
Selection of word concepts, grammatical
construction
Ordering parts of sentence, adding inflection
Morpheme exchange errors (trunked two packs),
spoonerisms (hissed my mystery lectures) within
same clause
Phonological and prosodic elements worked out
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WEAVER (Word-Form Encoding by Activation and
Verification)
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Neuropsychological evidence of staged selection

• Content-word retrieval vs. syntactic processing
• Distinction between anomia (e.g., word selection
  difficulties) vs. agrammatism (inability to
  construct grammatically correct sentences)
• Jargon aphasia can construct grammatically
  correct sentences but not find correct words

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Processes in Writing (Hayes Flower, 1980)

• Planning generating info from LTM, organizing
• Translating producing language conforming in
  meaning to that retrieved in the planning stage
• Reviewing editing what is written

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Deep Dysgraphia
Phonological Dysgraphia
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Language Disorders
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Types of Disorders

• Aphasia acquired disorder of language due to
  brain damage
• Dysarthria disorder of motor apparatus of
  speech
• Developmental language disturbances
• Associated disorders
• Alexia
• Apraxia
• Agraphia

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Major Historical Landmarks

• Broca (1861) Leborgne loss of speech fluency
  with good comprehension
• Wernicke (1874) Patient with fluent speech but
  poor comprehension
• Lichtheim (1885) classic description of aphasic
  syndromes

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C
A
M
Lichtheims Model
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Arcuate fasciculus
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Contemporary anologues of Lichtheims (1885)
Aphasic Syndromes
Syndrome Symptom Deficit Lesion
Brocas Aphasia ? speech production sparse, halting speech, missing function words, bound morphemes Impaired speech planning and production Posterior aspects of 3rd frontal convolution
Wernickes Aphasia ? Auditory comprehension, fluent speech, paraphasia, poor repetion and naming Impaired representation of sound structure of words Posterior half of the first temporal gyrus
Pure motor speech disorder Disturbance of articulation, apraxia of speech, dysarthria, aphemia Disturbance of articulation Outflow from motor cortex
Pure Word Deafness Disturbance of spoken word comprehension, repetition also impaired Failure to access spoken words Input tracks from auditory cortex to Wernickes area
Transcortical Motor Aphasia Disturbed spontaneous speech similar to BA relatively preserved repetition, comprehension Disconnection between conceptual word/sentence representations and motor speech production Deep white matter tracks connecting BA to parietal lobe
Transcortical Sensory Aphasia Disturbance in single word comprehension with relatively intact repetition Disturbed activation of word meanings despite normal recognition of auditorily presented words White matter tracks connecting parietal and temporal lobe
Conduction Aphasia Disturbance of repetition and spontaneous speech, phonemic paraphasia Disconnetion between sound patterns and speech production mechanisms Arcuate fasciculus connection between BA and WA
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Additional Aphasia Syndromes
Syndrome Symptom Deficit Lesion
Anomic Aphasia ? single-word production, marked for common nouns repetition and comprehension intact Impaired storage or access to lexical entries Inferior parietal lobe or connections within perisylvian language areas
Global Aphasia ? Performance in all language functions Disruption of all/most language components Multiple perisylvian language components
Isolation of the language zone ? Spontaneous speech, comprehension, some preservation of repetition echolalia common Disconnection between concepts and both representations of word sounds and speech production Cortex outside perisylvian association cortex
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Brocas Aphasia

• Telegraphic, effortful speech
• Agrammatism
• Some degree of comprehension deficit
• Writing and reading deficits
• Repetition abnormal drops function words
• Buccofacial apraxia, right hemiparesis

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M.E. Cinderella ... poor ... um 'dopted her ...
scrubbed floor, um, tidy ... poor, um ...
'dopted ... Si-sisters and mother ... ball.
Ball, prince um, shoe ... Examiner. Keep
going. M.E. Scrubbed and uh washed and
un...tidy, uh, sisters and mother, prince, no,
prince, yes. Cinderella hooked prince.
(Laughs.) Um, um, shoes, um, twelve o'clock
ball, finished. Examiner. So what happened in
the end? M.E. Married. Examiner. How does he
find her? M.E. Um, Prince, um, happen to, um
... Prince, and Cinderalla meet, um met um
met. Examiner. What happened at the ball? They
didn't get married at the ball. M.E. No, um,
no ... I don't know. Shoe, um found shoe ...
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Wernickes Aphasia

• Fluent, nonsensical speech
• Impaired comprehension
• Grammar better preserved than in BA
• Reading impairment often present
• May be aware or unaware of deficit
• Finger agnosia, acalculia, alexia without agraphia

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Wernicke description of Cookie Theft Picture
C.B. Uh, well this is the ... the /dødøü/ of
this. This and this and this and this. These
things going in there like that. This is /sen/
things here. This one here, these two things
here. And the other one here, back in this
one, this one /gø/ look at this one. Examiner.
Yeah, what's happening there? C.B. I can't
tell you what that is, but I know what it is, but
I don't now where it is. But I don't know
what's under. I know it's you couldn't say it's
... I couldn't say what it is. I couldn't say
what that is. This shu-- that should be right
in here. That's very bad in there. Anyway, this
one here, and that, and that's it. This is the
getting in here and that's the getting around
here, and that, and that's it. This is getting
in here and that's the getting around here,
this one and one with this one. And this one,
and that's it, isn't it? I don't know what else
you'd want.
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Conduction Aphasia

• Fluent language
• Naming and repetition impaired
• May be able to correct speech off-line
• Hesitations and word-finding pauses
• May have good reading skills

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Global Aphasia

• Deficits in repetition, naming, fluency and
  comprehension
• Gradations of severity exist
• May communicate prosodically
• Involve (typically) large lesions
• Outcome poorest anomic

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Transcortical Aphasias

• Transcortical Motor
• Good repetition
• Impairment in producing spontaneous speech
• Good comprehension
• Poor naming

• Transcortical Sensory
• Good repetition
• Fluent speech
• Impaired comprehension
• Poor naming
• Semantic associations poor

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Associated Deficits

• Alexia without Agraphia
• Impairment in reading with spared writing
• Apraxia
• Loss of skilled movement not due to weakness or
  paralysis

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Fundamental Lessons

• Language processors are localized
• Different language symptoms can be due to an
  underlying deficit in a single language processor
• Language processors are regionally associated
  with different parts of the brain in proximity to
  sensory or motor functions

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What Language Disorders Reveal about Underlying
Processes

• Pure Word Deafness selective processing of
  speech sounds implies a specific speech-relevant
  phonological processor
• Transcortical Sensory Aphasia repetition is
  spared relative to comprehension selective loss
  of word meaning some cases suggest
  disproportionate loss of one or more categories

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What Language Disorders Reveal about Underlying
Processes

• Aphasic errors in word production reveal
  complex nature of lexical access
• Phonological vs. semantic errors independent
  vs. interactive relationship?
• Grammatical class nouns vs. verbs (category
  specificity)
• Brocas aphasia syntax comprehension and
  production
• Central syntactic deficit loss of grammatic
  knowledge
• Problems in closed-class vocabulary
  (preposition, tense markers)
• Limited capacity account
• Mapping account (inability to map from parsing to
  thematic roles)
• Jargon Aphasia can construct gramatically
  better sentences than agrammatics, but cant
  find words, producing neologisms reinforces
  distinction between content and grammatical
  struture

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Prosody

• Linguistic vs. nonlinguistic prosody
• Evidence for hemispheric differences
• Clinical syndromes
• Disturbances of comprehension
• Auditory affective agnosia
• Phonagnosia
• Disturbances of prosodic output
• Aprosodias

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Spontaneous Prosody
Good
Poor
Ross Monnot (2007) Brain and Language
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Ross Monnot (2007) Brain and Language
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Aphasia and the Semantic System

• Meaning stored separately from form
• Models of representation in semantics
• Feature-based models (see categorization)
• Nondecompositional meaning
• Modality-specific semantic deficits optic
  aphasia as an example

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Two Example Models of Semantic Organization
One Semantic System
Multiple Semantic Systems