Title: Neurolinguistics
1Neurolinguistics
- Based on Libben (2000) Brain and Language
2Brain and Language
- 1.The human brain
- 1.1.The cerebral cortex
- 1.2.The cerebral hemispheres
- 1.3.The lobes of the cortex
- 2.Investigating the brain
- 2.1.Autopsy studies
- 2.2.Images of the living brain
- 2.3.Learning from hemispheric connections and
disconnections - Dichotic listening studies
- Split brain studies
- 3. Aphasia
- 3.1. Non-fluent aphasia
- Brocas aphasia as a syntactic disorder
- 3.2.Fluent aphasia (sensory aphasia)
- -Wernickes aphasia
- -Jargonaphasia
4.Acquired dyslexia and dysgraphia 4.1.Reading
and writing disturbances in aphasia -paragraphia
4.2.Acquired dyslexia as the dominant language
deficit -phonological dyslexia -surface
dyslexia 5.Linguistic theory and
aphasia 5.1.Features, rules, and underlying
forms 5.2.Agrammatism 5.3.Function words 5.4.Loss
of syntactic confidence 5.5.Agrammatism in other
languages 6.Where is language?
3Introduction
- Neurolinguistics How language is represented and
processed in the brain. - -survey of brain structure
- -methods to study the brain
- -language disturbances that result from brain
damage - -how phonology, morphology, syntax, and semantics
may be represented in the brain - -Where is language?
41.The human brain
- 1400 grs of pinkish-white matter
- Neuroscience how the breadth and depth of human
experience is coded in the brain matter. - Neurons basic information-processing units of
the nervous system - 10 Billion neurons
- Each neuron can link with 10 thousand others
- 1.1.The cerebral cortex
- Spinal cord VS Brain VS cerebral cortex
- Human VS animals
- Folded
51.The human brain (Continued)
- 1.2.The cerebral hemispheres
- Sulci (fissure)
- Gyri
- Longitudinal fissure, cerebral hemispheres,
corpus callasum - Contralateral responsibilities, Left hemisphere
controls the right side and vice versa - Left-hemisphere analytical tasks, such as
arithmetics - Right-hemisphere overall appreciation of
complex patterns, such as face recognition,
melodies - But, complex mental activities involve the
coordinated functioning of both hemispheres - Right-handed and left lateralized for language
- Left-hemisphere is removed but still comprehends
some language - Right-hemisphere damaged, difficulty in
understanding jokes and metaphors - Left-handers are less lateralized for language
-
- 1.3.The lobes of the cortex
- Lobe substructures of the cortex
- Occipital lobe, plays an important role in
reading
62.Investigating the brain
- Techniques to investigate what is going on in the
brain when people are engaged in language
behavior. - 2.1.Autopsy studies
- Observe patients behavior and, once dead,
examine his brain. - Brocas research, Brocas area, Brocas aphasia
- 2.2.Images of the living brain
- Computerized Axial Tomography (CT scanning)
- Positron Emission Tomography (PET), glucose
isotopes - Functional Magnetic Resonance Imaging (fMRI)
- It was found that when people
- -speak, blood flows to left hemisphere and
Brocas area - -read, occipital lobe, angular gyrus, other
areas of the left hemisphere - -SL processing involves a wider variety of
cortical sites, less automatic nature of language
requires additional diverse mental processes
72.Investigating the brain (continued)
- 2.3.Learning from hemispheric connections and
disconnections - Examining behavior that can be associated with a
particular brain hemisphere - Dichotic listening studies
- -language is processed better through right ear
(Right Ear Advantage, REA) - Split brain studies
- -Studying effects of the removal of corpus
callosum on cognition - -blindfolded patients holding a key in left
hand cannot name it
83. Aphasia
- -stroke (a cerebrovascular accident)
- -aphasia (language deficit caused by a damage to
the brain) - -Mosss experience
-
- 3.1. Non-fluent aphasia (motor aphasia)
- -damage to the front central sulcus
- -effortful speech production
- -global aphasia, completely mute
- -Brocas aphasia, some phonemes miss,
dysprosody, phonemic paraphasias - -Brocas area has a language specific
responsibility - Brocas aphasia as a syntactic disorder
- -function words are omitted telegraphic speech
- -disturbance of syntactic competence
- -omit inflectional suffixes
- -grammaticality judgment is difficult, The
boy ate up it. - -cannot interpret based on the syntax of the
sentence, The cat chased by the mouse. - -Brocas aphasia is not simply a production
deficit - -Brocas aphasics are acutely aware of their
language deficit - -Brocas area of frontal lobe does not seem to
be involved in the semantic relationships between
words
93. Aphasia (continued)
- 3.2.Fluent aphasia (sensory aphasia)
- -damage to the left cortex behind the central
sulcus - -language production is OK but difficulty in
selecting, organizing, and monitoring the
production - -Wernickes aphasia
- -generally unaware of their deficit
- -everything seems normal except rarely make
sense - -comprehension deficit
- -no coherent trains of thought
- -Jargonaphasia, Severe case of Wernickes
aphasia, intonational charecteristics of the
language is OK, but very few actual sentences
104.Acquired dyslexia and dysgraphia
- Dyslexia impairment of reading ability
- Dysgraphia impairment of writing ability
- Acquired VS developmental dyslexia dysgraphia
- 4.1.Reading and writing disturbances in aphasia
- -whatever impairment the patient has in
listening and speaking will be matched in reading
and writing. - -most Brocas aphasics show writing
disturbances that are comparable to their
speaking deficits - -the resulting error is paragraphia
- -production deficit at a very deep level of
language planning - -Wernickes aphasia, like Brocas aphasia
involves a central disturbance of language
competence
114.Acquired dyslexia and dysgraphia (continued)
- 4.2.Acquired dyslexia as the dominant language
deficit - -damage in and around the angular gyrus of the
parietal lobe - -theory readers maintain a set of
spelling-to-sound rules that enables them to read
new words aloud. - -phonological dyslexia loosing
spelling-to-sound rules not able to read unknown
words - -surface dyslexia the opposite, processing
words only spelling-to-sound rules, regularly
spelled words are OK, but irregularly spelled
words are poblematic worm is perceived as
opposite of cold.
125.Linguistic theory and aphasia
- For aphasia researchers
- -Not simply what the patients can or cannot do
- -but the deficit in terms of the loss of
semantic features, phonological features,
phonological rules, and syntactic tree structures - For Theoretical linguists
- -distinctions between derivational and
inflectional suffixes - 5.1.Features, rules, and underlying forms
- -phonological features and rules may be good
tools to characterize how language is represented
and produced (with vs /wit/) - -morphology inflectional is dropped,
derivational is retained - -illegal ? inlegal
- -semantics deep dyslexia father ?mother.
- -abstract words are more difficult to produce
than concrete ones - -concrete words are more difficult than
abstract words selective inability inability to
produce names for fruits and vegetables -
135.Linguistic theory and aphasia (continued)
- 5.2.Agrammatism
- -agrammatism telegraphic speech, grammar is
lost, omission of function words and inflectional
affixes - -comprehension deficit where correct
interpretation solely depends on syntax - -characteristics of the syndrome and
characteristics of particular languages - 5.3.Function words
- -prepositions are they function words or
lexical words? - 5.4.Loss of syntactic confidence
- -is hierarchical representation lost? Assigning
meaning to first noun rather than the NP -
- 5.5.Agrammatism in other languages
- -true nature of agrammatism is not dropping
function words and inflectional affixes. - -Hebrew kotev (writes) VS katev (wrote)
- -so, it is not simply an economy effort,
misselection of linguistic forms
146.Where is language?
- Brocas area -articulation of speech
- -create syntactic representation
- Wernickes area -language comprehension
- Right above Wernickes area, angular gyrus
reading - Normal language use involves the integrated
functioning of the entire cortex. - Storage and retrieval of word forms may be
diffusely represented in the brain. - What is language is a more important question.
15Summing up
- Left-hemisphere of the brain carries most of the
responsibility for language processing. - Most of our knowledge about language
representation comes from the study of
aphasialanguage disturbance resulting from
damage to the brain.
16Questions
- 1.What distinguishes the human brain from a
non-human brain? - 2.In what ways can the cerebral hemispheres be
considered to be two separate brains?