Cognitive Psychology

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Cognitive Psychology Chapter 9, Pt. IV Language
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10/16/2009

• Language, cont
• Neuropsychology
• Brocas aphasia
• Wernickes aphasia
• Classical localization model
• Neurophysiology
• ERP studies

Study Question. Describe the classical
localization model of brain and language. How do
different types of aphasias relate to the model.
Give examples.
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Brain Language

• Neuropsychology of language

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Brain Language

• Neuropsychology of language
• Aphasia Language deficits resulting from
  brain-related disorders and injury.

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Brain Language

• Neuropsychology of language
• Aphasia Language deficits resulting from
  brain-related disorders and injury.
• Very common
• 40 of all strokes produce some aphasia
• Brocas Aphasia
• Paul Broca - studied patient Leborgne
  (A.K.A.Tan)
• Treated for leg injury
• Died a few days later
• Autopsied brain
• Discovered Brocas area
• Left Hemisphere dominance for language

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Brain Language

• Neuropsychology of language
• Brocas Aphasia

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Brain Language

• Neuropsychology of language
• Brocas Aphasia

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Brain Language

• Neuropsychology of language
• Brocas Aphasia
• Production Deficits (expressive or nonfluent)
• Problems in producing fluent language
• Range from Tono,tono,tono, to short phrases
• Lack function words and grammar
• May retain idioms (fit as a fiddle) or songs
• Proximity to motor cortex
• Dysarthria loss of control over articulatory
  muscles
• Speech Apraxia Unable to program voluntary
  articulatory movements.

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Brain Language

• Neuropsychology of language
• Brocas Aphasia
• Comprehension deficits (receptive or fluent)
• Unable to analyze precise grammatical information
• E.g.
• The Boy ate the cookie
• Who ate the Cookie?
• Boy ate cookie
• Implied grammar (cookies dont eat boys)
• The Boy was kicked by the girl
• Who kicked whom?
• Boy kick girl

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Brain Language

• Neuropsychology of language
• Wernickes Aphasia
• Carl Wernicke, 1870s
• Examined two stroke patients
• Problems understanding language
• Fluent but nonsensical speech
• Poor language comprehension
• Proximity to auditory sensory areas
• (Wernicke proposed word memory area)

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Brain Language

• Neuropsychology of language
• Wernickes Aphasia

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Brain Language

• Neuropsychology of language
• Wernickes Aphasia
• Production deficits
• Sounds fluent (e.g., foreign language)
• Neologistic (invented words)
• Semantic substitutions
• E.g.
• I called my mother on the television and did not
  understand the romers by the door.

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Brain Language

• Neuropsychology of language
• Wernickes Aphasia
• Comprehension deficits
• Do not recognize the incomprehensibility of
  their own sentences
• Do not comprehend written or spoken language
• Here and gone again
• Aphasia improves over time
• Anomia Losing the ability to retrieve words
  (nouns)

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Brain Language

• Neuropsychology of language
• Classical localization model (Lichtheim, 1885
  Geschwand, 1967)

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Brain Language

• Neuropsychology of language
• Classical localization model (Lichtheim, 1885
  Geschwand, 1967)
• Damage to main areas
• Brocas Aphasia
• Wernickes Aphasia
• Damage to connections
• Transcortical motor aphasia
• Transcortical sensory aphasia
• Conduction aphasia

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Brain Language

• Neuropsychology of language
• Conduction aphasia
• Damage to the connection between Wernickes and
  Brocas area
• Arcuate Fasciculus

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Brain Language

• Neuropsychology of language
• Conduction aphasia
• Production deficits
• Speech is generally fluent
• Problems producing spontaneous speech
• Problem repeating speech
• Sometimes use words incorrectly
• Phonological transpositions (velitision for
  television)
• Comprehension
• Can understand spoken/written words
• Can hear their own speech errors, but cannot
  correct them
• Oral reading is poor

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Brain Language

• Neuropsychology of language
• A prediction
• Disconnecting Wernickes from the conceptual
  area should lead to repetition without
  comprehension.
• Transcortical Sensory Aphasia
• Damage to the angular gyri

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Brain Language

• Neuropsychology of language
• Transcortical Sensory Aphasia
• Production deficits
• Fluent grammatical speech
• Show semantic paraphasia (using the wrong word)
• E.g., Apple for orange
• Comprehension
• Poor comprehension
• Repetition without comprehension

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Brain Language

• Neurophysiology of language in the intact brain
• ERP studies
• The N400 Semantic violations

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Brain Language

• Neurophysiology of language in the intact brain
• ERP studies
• The P600 Syntactic Positive Shift (syntactic
  violation)

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Brain Language

• Neurophysiology of language in the intact brain
• Dispreferred continuation of ambiguous sentences
• E.g.,
• The spy saw the cop with the binoculars
• Who has the binoculars?
• The spy has the binoculars -gt preferred
  continuation
• The N400 and aphasia
• Swaab et al.
• Patients listened to sentences that had an
  anomalous word at the end.

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Brain Language

• Neurophysiology of language in the intact brain
• Swaab et al. (1997)

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Brain Language

• Neurophysiology of language in the intact brain
• A caveat Individual differences
• Stimulation mapping of the brain
• Neurosurgery around left hemisphere language
  areas
• A couple hundred of patients
• Correlation with effects in Wernicke and Brocas
  area are weak
• Some patients have naming problems in the area,
  not all.
• Anatomical localizations vary considerably.

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Brain Language

• Neurophysiology of language in the intact brain

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Brain Language

• Neurophysiology of language in the intact brain
• A caveat Individual differences