Neurolinguistics
Leiden University: BA Linguistcs
1. general introduction:
- neurolinguistics:
- the relationship between language and brain functions
- how does the brain comprehend and produce language?
- much overlap with psycholinguistics, but a stronger focus on the brain
- two sub-areas: - 1. language processing after brain damage
- 2. experimental studies with neuroimaging
- neurological/neurophysiological theory: - how is the brain structured and how does it work?
- linguistic theory: - how is language structured and how does it work?
- psychology and cognitive neuroscience → strong interdisciplinary character
- aspects of neurolinguistics:
- developmental language disorders
- developed in the course of language acquisition
- SLI - specific language impairment
- developmental dyslexia - developmental disorder in reading (and writing - dysgraphia)
- language evolution
- changes in the structure and function of the brain are compared to various other species
(cross-species research)
- animal communication is studied under natural conditions and in the laboratory
- measuring brain activity
- during language processing in healthy and damaged brains
- CT scans (computer tomography; X-ray)
- (f)MRI ((functional) magnetic resonance imaging) - method of choice (nowadays)
- EEG (electroencephalography)
- PET (positron emission tomography)
- MEG (magnetic encephalography)
- aphasia - loss of language due to brain damage
- infarct (blockage of a blood vessel)
- haemorrhage (burst of a blood vessel)
- skull trauma
- classical aphasiology (ca. 150 years ago)
- provided detailed description of clinical syndromes as the result of lesions to particular areas of
the brain
- Alexander Luria (1902-1977):
- “What are the real processes of formation of verbal communication and its comprehension, and what
are the components of these processes and the conditions under which they take place?”
- important Russian neuropsychologist
- especially well-known in the field of aphasia
- Paul Broca (1824-1880):
- patient Leborgne (“Tan”)
- on April 11th 1861, Broca met this patient in the hospital Bicetre in Paris
, - he lost the ability to speak at the age of 30
- he understood everything but could only utter “tan, tan”
- for 10 years, his right arm and leg were paralyzed
- Broca: Leborgne has aphemia (“no speech”; later became aphasia)
- he dies on April 17th 1861
- Broca performed an autopsy within 24 hours; a few hours later, Leborgne’s brain is shown to the
Anthropological Society, after which the organ was placed in alcohol
- why is Broca’s discovery important?
- 1. Broca showed that it is possible to locate important psychological functions in the brain
- 2. Broca showed that the linguistic symptoms were caused by damage in the left hemisphere
and that language, therefore, is lateralized (which was completely unexpected)
- Broca’s area - responsible for the expressive language function
- Broca’s aphasia:
- also known as expressive aphasia
- individuals have difficulty producing language (spoken, manual, written)
- Carl Wernicke (1848-1905):
- neurologist
- presented findings in 1874 about brains of patients who have problems understanding language
- “damage in Wernicke’s or Broca’s area or the connection between these areas causes aphasia”
- introduces the idea of a flow of information in the brain
- predicts the phenomenon of conduction aphasia which arises when the connection between Broca’s
and Wernicke’s area is damaged (while these two areas are not damaged)
- Wernicke’s area - “posterior part of the first or superior temporal gyrus and adjacent areas such as
parts of the angular gyrus, the supramarginal gyrus, and the second temporal gyrus”
- responsible for the receptive language function
- Wernicke’s aphasia:
- also known as receptive/sensory/posterior aphasia
- individuals have difficulty understanding written and spoken language
Broca-Wernicke-Lichtheim model holds:
- a) auditory input and analysis of auditory word representations in Wernicke’s area
- b) transmission to Broca’s area (from Wernicke’s) where motor word representations are formed and
executed (articulation; repetition)
- c) or transmission from the concept center where the interpretation of the meaning of words takes place
(language comprehension) (to Broca’s)
- Ludwig Lichtheim (1845-1928):
- proposes a third language center (unspecified location) - concept center
- language production could also begin at the concept center (see Wernicke-Lichtheim model below)
- in this case, concepts are sent to Broca’s area where the motor word representations are
executed)
, Wernicke-Lichtheim “House” Model (1885)
A - auditory center
M - motor center
B - ideation (“Begriffe”) (concept center) - the
meaning of the words is located here
- the numbers indicate areas or connections
between areas where damage could lead to
aphasia
- brain diagrams:
- industry of diagram makers
- Wernicke and Lichtheim (diagram makers) identified centers (regions) in the brain that are
specialized for particular language functions
- diagrams mapped out these centers and the connection between them
- damage to these functional centers or the connections between them causes classical aphasia
syndromes
⇒ working models characterizing language deficits in aphasia
- aphasias:
- conduction aphasia
- disruption in the connection between Wernicke’s and Broca’s area
→ normal comprehension, impaired repetition
- transcortical sensory aphasia
- disruption in the connection between Wernicke’s area and concept center
→ impaired comprehension, normal repetition
- transcortical motor aphasia
- disruption in the connection between concept center and Broca’s area
→ normal comprehension, impaired spontaneous speech, normal repetition
- linguistics and aphasia:
- in the mid-20th century, there were only neurologists; linguists start to become interested in aphasia
- by analyzing functionally different disorders using the descriptive method of linguistics, they try to
better understand the role of the brain during normal speech → neurolinguistics
- Norman Geschwind: “Disconnection syndromes in animals and man” (1965) - leads to dynamic
localization of function (came before with Alexander Luria)
- Roman Jakobson: “Kindersprache, Aphasie und allgemeine Lautgesetze” (1941) - applies linguistic
principles to the description of aphasia; he showed how language acquisition and
aphasia are connected
- Noam Chomsky: (1957, 1965) - aphasia as a test for psychological reality of his linguistic theories
2. neuroanatomy:
- (functional) neuroanatomy
- study of the structure of the nervous system
,- new terms: - gyrus - a convolution
- sulcus - a small in-folding (a small groove)
- fissure - a large in-folding (a large groove)
- corpus callosum - interconnects different cortical areas in the two hemispheres
- fasciculi - interconnects different cortical areas in the same hemisphere
- Andreas Vesalius (1514-1564):
- (actually Andries van Wesel)
- doctor and anatomist from Brabant
- first complete book on human anatomy “The humani corporis fabrica libri septem” (1543) (“Seven
books on the structure of the human body”)
, - layout of the brain:
telencephalon diencephalon mesencephalon metencephalon myelencephalon
- telencephalon:
- cerebral cortex
- limbic system
- basal ganglia
- cerebral cortex:
- forms the outer surface of the cerebral hemispheres
- consists of 2 hemispheres
- largest part of the brain
- composed of gray and white matter
- gray matter: - surrounds the cerebral hemisphere like the bark of a tree
- cell bodies of neurons (gray color)- primary composition of cerebral cortex
- most recently developed part of the brain (from an evolutionary point of view)
- white matter: - fatty myelin (glial cells) around the axons
- is formed from 6 layers of cells (ca. 3 mm from top to bottom, depending on the location)
Leiden University: BA Linguistcs
1. general introduction:
- neurolinguistics:
- the relationship between language and brain functions
- how does the brain comprehend and produce language?
- much overlap with psycholinguistics, but a stronger focus on the brain
- two sub-areas: - 1. language processing after brain damage
- 2. experimental studies with neuroimaging
- neurological/neurophysiological theory: - how is the brain structured and how does it work?
- linguistic theory: - how is language structured and how does it work?
- psychology and cognitive neuroscience → strong interdisciplinary character
- aspects of neurolinguistics:
- developmental language disorders
- developed in the course of language acquisition
- SLI - specific language impairment
- developmental dyslexia - developmental disorder in reading (and writing - dysgraphia)
- language evolution
- changes in the structure and function of the brain are compared to various other species
(cross-species research)
- animal communication is studied under natural conditions and in the laboratory
- measuring brain activity
- during language processing in healthy and damaged brains
- CT scans (computer tomography; X-ray)
- (f)MRI ((functional) magnetic resonance imaging) - method of choice (nowadays)
- EEG (electroencephalography)
- PET (positron emission tomography)
- MEG (magnetic encephalography)
- aphasia - loss of language due to brain damage
- infarct (blockage of a blood vessel)
- haemorrhage (burst of a blood vessel)
- skull trauma
- classical aphasiology (ca. 150 years ago)
- provided detailed description of clinical syndromes as the result of lesions to particular areas of
the brain
- Alexander Luria (1902-1977):
- “What are the real processes of formation of verbal communication and its comprehension, and what
are the components of these processes and the conditions under which they take place?”
- important Russian neuropsychologist
- especially well-known in the field of aphasia
- Paul Broca (1824-1880):
- patient Leborgne (“Tan”)
- on April 11th 1861, Broca met this patient in the hospital Bicetre in Paris
, - he lost the ability to speak at the age of 30
- he understood everything but could only utter “tan, tan”
- for 10 years, his right arm and leg were paralyzed
- Broca: Leborgne has aphemia (“no speech”; later became aphasia)
- he dies on April 17th 1861
- Broca performed an autopsy within 24 hours; a few hours later, Leborgne’s brain is shown to the
Anthropological Society, after which the organ was placed in alcohol
- why is Broca’s discovery important?
- 1. Broca showed that it is possible to locate important psychological functions in the brain
- 2. Broca showed that the linguistic symptoms were caused by damage in the left hemisphere
and that language, therefore, is lateralized (which was completely unexpected)
- Broca’s area - responsible for the expressive language function
- Broca’s aphasia:
- also known as expressive aphasia
- individuals have difficulty producing language (spoken, manual, written)
- Carl Wernicke (1848-1905):
- neurologist
- presented findings in 1874 about brains of patients who have problems understanding language
- “damage in Wernicke’s or Broca’s area or the connection between these areas causes aphasia”
- introduces the idea of a flow of information in the brain
- predicts the phenomenon of conduction aphasia which arises when the connection between Broca’s
and Wernicke’s area is damaged (while these two areas are not damaged)
- Wernicke’s area - “posterior part of the first or superior temporal gyrus and adjacent areas such as
parts of the angular gyrus, the supramarginal gyrus, and the second temporal gyrus”
- responsible for the receptive language function
- Wernicke’s aphasia:
- also known as receptive/sensory/posterior aphasia
- individuals have difficulty understanding written and spoken language
Broca-Wernicke-Lichtheim model holds:
- a) auditory input and analysis of auditory word representations in Wernicke’s area
- b) transmission to Broca’s area (from Wernicke’s) where motor word representations are formed and
executed (articulation; repetition)
- c) or transmission from the concept center where the interpretation of the meaning of words takes place
(language comprehension) (to Broca’s)
- Ludwig Lichtheim (1845-1928):
- proposes a third language center (unspecified location) - concept center
- language production could also begin at the concept center (see Wernicke-Lichtheim model below)
- in this case, concepts are sent to Broca’s area where the motor word representations are
executed)
, Wernicke-Lichtheim “House” Model (1885)
A - auditory center
M - motor center
B - ideation (“Begriffe”) (concept center) - the
meaning of the words is located here
- the numbers indicate areas or connections
between areas where damage could lead to
aphasia
- brain diagrams:
- industry of diagram makers
- Wernicke and Lichtheim (diagram makers) identified centers (regions) in the brain that are
specialized for particular language functions
- diagrams mapped out these centers and the connection between them
- damage to these functional centers or the connections between them causes classical aphasia
syndromes
⇒ working models characterizing language deficits in aphasia
- aphasias:
- conduction aphasia
- disruption in the connection between Wernicke’s and Broca’s area
→ normal comprehension, impaired repetition
- transcortical sensory aphasia
- disruption in the connection between Wernicke’s area and concept center
→ impaired comprehension, normal repetition
- transcortical motor aphasia
- disruption in the connection between concept center and Broca’s area
→ normal comprehension, impaired spontaneous speech, normal repetition
- linguistics and aphasia:
- in the mid-20th century, there were only neurologists; linguists start to become interested in aphasia
- by analyzing functionally different disorders using the descriptive method of linguistics, they try to
better understand the role of the brain during normal speech → neurolinguistics
- Norman Geschwind: “Disconnection syndromes in animals and man” (1965) - leads to dynamic
localization of function (came before with Alexander Luria)
- Roman Jakobson: “Kindersprache, Aphasie und allgemeine Lautgesetze” (1941) - applies linguistic
principles to the description of aphasia; he showed how language acquisition and
aphasia are connected
- Noam Chomsky: (1957, 1965) - aphasia as a test for psychological reality of his linguistic theories
2. neuroanatomy:
- (functional) neuroanatomy
- study of the structure of the nervous system
,- new terms: - gyrus - a convolution
- sulcus - a small in-folding (a small groove)
- fissure - a large in-folding (a large groove)
- corpus callosum - interconnects different cortical areas in the two hemispheres
- fasciculi - interconnects different cortical areas in the same hemisphere
- Andreas Vesalius (1514-1564):
- (actually Andries van Wesel)
- doctor and anatomist from Brabant
- first complete book on human anatomy “The humani corporis fabrica libri septem” (1543) (“Seven
books on the structure of the human body”)
, - layout of the brain:
telencephalon diencephalon mesencephalon metencephalon myelencephalon
- telencephalon:
- cerebral cortex
- limbic system
- basal ganglia
- cerebral cortex:
- forms the outer surface of the cerebral hemispheres
- consists of 2 hemispheres
- largest part of the brain
- composed of gray and white matter
- gray matter: - surrounds the cerebral hemisphere like the bark of a tree
- cell bodies of neurons (gray color)- primary composition of cerebral cortex
- most recently developed part of the brain (from an evolutionary point of view)
- white matter: - fatty myelin (glial cells) around the axons
- is formed from 6 layers of cells (ca. 3 mm from top to bottom, depending on the location)
