Neurolinguistics: Brain and Language Sydney Lamb Ling/Anth 411

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 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 address Major(s)Class Previous linguistics courses Previous neuroscience courses Previous cognitive science courses Languages Why this course?

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.. More..

The brain  Medulla oblongata – Myelencephalon  Pons and Cerebellum – Metencephalon  Midbrain – Mesencephalon  Thalamus and hypothalamus – Diencephalon  Cerebral hemispheres – Telencephalon Brain Stem Alternative partition: Brain stem Cerebellum Thalamus & hypothalamus Cerebral hemispheres

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

Thalamus and Cortex  We will concentrate on the cortex  But the thalamus is also very important Relatively neglected Too bad!  I wish I knew more about it  Metaphor: The cortex is the orchestra  A very large orchestra About 30 million members The thalamus is the conductor  Also very important: the Basal Ganglia

Two hemispheres Left Right Interhemispheric fissure (a.k.a. longitudinal fissure)

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 Sylvian fissure Frontal Lobe Parietal Lobe Temporal Lobe Occipital Lobe

Primary motor and somatosensory areas Central Sulcus Sylvian fissure Primary Motor Area Primary Somato- sensory 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 Somato- sensory Area Primary Motor Area Primary Auditory Area Primary Visual Area

Divisions of Primary Motor and Somatic Areas Primary Somato- sensory Area Primary Motor Area Primary Auditory Area Primary Visual Area Mouth Hand Fingers Arm Trunk Leg

Higher level motor areas Primary Somato- sensory Area Actions performed by hand Primary Auditory Area Primary Visual Area Mouth Hand Fingers Arm Trunk Leg Actions per- Formed by leg Actions performed by mouth

Two basic language areas Primary Somato- sensory Area Primary Motor Area Primary Auditory Area Primary Visual Area Mouth Hand Fingers Arm Trunk Leg Phonological Recognition Phonological Production

Areas important for language

View from the top.. Supramarginal gyrus Angular gyrus

Principal cortical gyri (schematic)

Arcuate Fasciculus (from langbrain website)

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

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