Neurolinguistics
Based on Libben (2000) “Brain and
Language”
Brain 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
•Broca’s aphasia as a syntactic
disorder
3.2.Fluent aphasia (sensory aphasia)
-Wernicke’s 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?
Introduction
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?
1.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
1.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
2.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 patient’s behavior and, once dead, examine his brain.
Broca’s research, Broca’s area, Broca’s 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 Broca’s 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
2.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
3. Aphasia
-stroke (a cerebrovascular accident)
-aphasia (language deficit caused by a damage to the brain)
-Moss’s experience
3.1. Non-fluent aphasia (motor aphasia)
-damage to the front central sulcus
-effortful speech production
-global aphasia, completely mute
-Broca’s aphasia, some phonemes miss, dysprosody, phonemic paraphasias
-Broca’s area has a language specific responsibility
•Broca’s 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.”
-Broca’s aphasia is not simply a production deficit
-Broca’s aphasics are acutely aware of their language deficit
-Broca’s area of frontal lobe does not seem to be involved in the semantic relationships between words
-and the relationship between units of language and units of thought.
3. 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
-Wernicke’s aphasia
-generally unaware of their deficit
-everything seems normal except rarely make sense
-comprehension deficit
-no coherent trains of thought
-Jargonaphasia, Severe case of Wernicke’s aphasia,
intonational charecteristics of the language is OK, but very few
actual sentences
4.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 Broca’s 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
-Wernicke’s aphasia, like Broca’s aphasia involves a central
disturbance of language competence
4.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”.
5.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
5.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
6.Where is language?
Broca’s area: -articulation of speech
-create syntactic representation
Wernicke’s area: -language comprehension
Right above Wernicke’s 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.
Summing 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
aphasia—language disturbance resulting from
damage to the brain.
Questions
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?
[…]