Transcript Ling411-01 - OWL-Space

Ling/Anth 411
Neurolinguistics: Brain and Language
Sydney Lamb
Introduction to the Course
Linguistics 411 – Neurolinguistics
Introduction and Course Outline
Basic Brain Anatomy
What this course is about
 Linguistic neuroscience
• A physical science of language
• Unlike ordinary linguistics
o Most ordinary linguistics focuses
on things people say – “texts”
• Linguistic neuroscience focuses on
the system responsible for texts
 The linguistic system of a person
 A system in the person’s brain
The linguistic system as an object
of scientific investigation
 It is represented in the brain
• The brain is a physical object
 Is it observable?
• Indirect observation
 Aphasiology
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Study of impaired linguistic systems
 Study of unimpaired linguistic systems
Direct observation
 Functional brain imaging
 Intra-operative mapping
The start of the investigation
 We have to be realistic
 We have to start with observable phenomena
 First observation:
• People talk with one another
• They must have some means of doing so
• Call it the linguistic system
 The linguistic system must have a location
• It is mainly in the cerebral cortex
• Known from aphasiology
Next steps in the investigation
 The cerebral cortex is a network
• Very large
• Dynamic
 Changes take place in connection strengths
 The linguistic system is part of the cortex
• Therefore it is a large dynamic network
• Not necessarily all in one part of the cortex
 In fact, we know it is not
 We know from aphasiology that it
• Occupies several different cortical regions
• These regions are interconnected
Linguistic neuroscience
 Linguistic neuroscience has a direct
relationship not only to cognitive
science but also to neuroscience
• Therefore, to biology
 Unlike ordinary linguistics
 But linguistic neuroscience provides a
bridge from neuroscience to other
linguistic pursuits
Quote from Norman Geschwind
I gather … that the status of linguistic theories
continues to be a difficult problem. … I would wish,
cautiously, to make the suggestion, that perhaps a
further touchstone may be added: to what extent
does the theory tie in with other, non-linguistic
information, for example, the anatomical aspects of
language? In the end such bridges link a theory to
the broader body of scientific knowledge. (1964)
The need to be realistic
 Operational plausibility
• The linguistic system has to be able to operate
 Developmental plausibility
• The linguistic system has to be able to be built
within the brain of a small child
 Neurological plausibility
• A theory of the structure of the linguistic system
must have a plausible relationship to what is
known about the brain from neuroscience
Information Card..
LastName, FirstName
Major(s)
Previous linguistics courses
Previous neuroscience courses
Previous cognitive science courses
Languages
Why this course?
email address
Class
Introduction to the Brain
Brain Anatomy
with special attention to
Linguistically Important Systems
The nervous system
 Central nervous system
• Spinal cord
• Brain
 Peripheral nervous system
• Motor and sensory neurons
connected to the spinal cord
The brain
Medulla oblongata – Myelencephalon
Pons and Cerebellum – Metencephalon
Midbrain – Mesencephalon
Thalamus and hypothalamus – Diencephalon
Cerebral hemispheres – Telencephalon
• Cerebral cortex
• Basal ganglia
• Basal forebrain nuclei
• Amygdaloid nucleus
 More..
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The brain
Brain Stem
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Medulla oblongata – Myelencephalon
Pons and Cerebellum – Metencephalon
Midbrain – Mesencephalon
Thalamus and hypothalamus – Diencephalon
Cerebral hemispheres – Telencephalon
Alternative partition:
Brain stem
Cerebellum
Thalamus & hypothalamus
Cerebral hemispheres
The brain
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Medulla oblongata – Myelencephalon
Pons and Cerebellum – Metencephalon
Midbrain – Mesencephalon
Thalamus and hypothalamus – Diencephalon
Cerebral hemispheres – Telencephalon
• Cerebral cortex
• Basal ganglia
• Basal forebrain nuclei
• Amygdaloid nucleus
Thalamus and Cortex
 We will concentrate on the cortex
 But the thalamus is also very important
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Relatively neglected
Too bad!
 I wish I knew more about it
 Metaphor:
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The cortex is the orchestra
 A very large orchestra
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About 30 million members
The thalamus is the conductor
 Also very important: the Basal Ganglia
Two hemispheres
Left
Interhemispheric fissure
(a.k.a. longitudinal
fissure)
Right
Corpus Callosum Connects Hemispheres
Corpus
Callosum
Major Left Hemisphere landmarks
Central Sulcus
Sylvian fissure
The Sylvian Fissure
Major landmarks and the four lobes
Central Sulcus
Frontal
Lobe
Parietal
Lobe
Temporal
Lobe
Sylvian fissure
Occipital
Lobe
Primary motor and somatosensory areas
Central Sulcus
Primary
Motor Area
Sylvian fissure
Primary Somatosensory Area
Some terms..
 Fissures and sulci
• Singular: sulcus – Plural: sulci
• The major sulci are usually called
fissures
 Interhemispheric fissure
 Sylvian fissure
 Sometimes the term Rolandic
fissure is used for the central
sulcus
 Gyri
• Singular: gyrus – Plural: gyri
Alternatives terms for some fissures
 Interhemispheric fissure
• Also known as Longitudinal fissure
 Sylvian fissure
• Also known as Lateral sulcus
 Central sulcus
• Also known as Rolandic fissure
Primary Areas
Primary Somatosensory Area
Primary
Motor Area
Primary Auditory
Area
Primary
Visual Area
Divisions of Primary Motor and Somatic Areas
Leg
Primary
Motor Area
Primary Somatosensory Area
Trunk
Arm
Hand
Fingers
Mouth
Primary Auditory
Area
Primary
Visual Area
Higher level motor areas
Actions perFormed by leg
Actions
performed
by hand
Leg
Primary Somatosensory Area
Trunk
Arm
Hand
Fingers
Actions
performed
by mouth
Mouth
Primary Auditory
Area
Primary
Visual Area
Two basic language areas
Leg
Primary
Motor Area
Primary Somatosensory Area
Trunk
Arm
Hand
Fingers
Phonological Mouth
Production
Primary Auditory
Area
Phonological
Recognition
Primary
Visual Area
Areas important for language
View from
the top..
Supramarginal gyrus
Angular gyrus
Principal cortical gyri (schematic)
Arcuate Fasciculus
(from langbrain website)
www.rice.edu/langbrain
Where is the linguistic system?
 Not in one place, but in several
interconnected areas
 Language involves operations
in multiple cortical modalities
 Each of them may also have
non-linguistic functions
 The hypothesis of a “language
organ” is implausible
end