Chapter 1 What is neurolinguistics?
- Neurolinguistics studies the relation of language and communication to different aspects of brain function, in other words it tries to explore how the brain understands and produces language and communication. Neurolinguistics has a very close relationship to psycholinguistics, but focuses more on studies of the brain. Studies of language and communication after brain damage are perhaps the most common type of neurolinguistic study. However, experiments, model construction, computer simulations, and neuroimaging studies are also very frequently used methods today.
- The main questions of interest for neurolinguistics were first addressed very far back in history. There was a period of intensified focus in the late 19th century; since then, they have become central to researches in many disciplines.
- "Neurolinguistics" became the established term for the field in the 1960s, under the influence of the Chomsky.
- Different views on the relation between brain and language:
Localism tries to find locations or centers in the brain for different language functions.
Associationism situates language functions in the connections between different areas of the brain, making it possible to associate, for example, perceptions of different senses with words and/ or "concepts".
Dynamic localization of function assumes that functional systems of localized subfunctions perform language functions.
Holistic theories consider many language functions to be handled by widespread areas of the brain working together.
Evolution-based theories stress the relationship between how the brain and language evolved over time in different species, how they develop in children, and how adults perform language functions. - The central questions of neurolinguistics:
What happens to language and communication after brain damage of different types?
How did the ability to communicate and the ability to use language develop as the species evolved? How can we relate this development to the evolution of the brain?
How do children learn to communicate and use language? How can we relate their acquisition of language to the development of their brains?
How can we measure and visualize processes in the brain that are involved in language and communication?
How can we make good models of language and communication processes that will help us to explain the linguistic phenomena that we study?
How can we make computer simulations of language processing, language development, and language loss?
How can we design experiments that will allow us to test our models and hypotheses about language processing?
Chapter 2 The development of theories about brain and language(P. 24 to be continued)
Different views of the language-brain relationship along the continuum from localism to holism:
Localism：different "higher functions" are localized in different centers of the brain, mainly the cortex. Either these centers can be seen as "sisters", being equally important, or one center, such as the prefrontal area( in front of the frontal lobes), may be seen as superordinate to the others. ( Aphasia is seen as the result of a lesion in a language center. Well-known localists included Gall and Broca.
Association( or connectionism): higher functions are dependent on the connections between different centers in the cortex. Linguistic ability is seen as the relationship between images and words.（Aphasia results from broken connections between the centers that are needed for linguistic function. Representatives of this view are Wernicke, Lichtheim, and Geschwind.
Dynamic localization of function: different subfunctions are seen as localized in different parts of the brain. These subfunctions must be combined in order to achieve more complex functions, which can be "put together" in a number of different ways.
Hierachical or evolution-based view: emphasize the layered structure of the brain from inner/lower and more primitive structures to the later developed and superimposed cortical layer and the role of all of these layers in language and communication.
Holism: the brain works as a whole, at least to accomplish higher functions. The cortex is said to handle "higher cognitive functions", "symbolic thinking", "intelligence", or "abstraction", and aphasia is a sign of a general cognitive loss, not a specific language loss.
Dynamic localization of function: different subfunctions are seen as localized in different parts of the brain. These subfunctions must be combined in order to achieve more complex functions, which can be "put together" in a number of different ways.
Hierachical or evolution-based view: emphasize the layered structure of the brain from inner/lower and more primitive structures to the later developed and superimposed cortical layer and the role of all of these layers in language and communication.
Holism: the brain works as a whole, at least to accomplish higher functions. The cortex is said to handle "higher cognitive functions", "symbolic thinking", "intelligence", or "abstraction", and aphasia is a sign of a general cognitive loss, not a specific language loss.
Unitarism: the soul is one and cannot be divided.
Equipotentiality: all parts of the cortex have the same functional potential and that the size of a brain lesion determines the extent of the aphasia( the mass effect).
Ideas about brain and language before the 19th century
Ancient Egypt, Greece, and Rome:
The first reference to the brain as the center of language is found in the Edwin Smith papyrus from about 3500 Bc.
In writings from Greek antiquity, language disorders are discussed by Hippocrates(400 BC). Around the same time, Democritus compared the brain to a guard or sentinel with two functions: the internal function of guarding the intelligence and the external function of guarding the senses. Herophilus localized intelligence in the ventricles of the brain at about 300 BC.
Plato(4th century BC) wanted to localize the different abilities of the soul in different parts of the brain, which he saw as the center of all senses. It was with Plato that the idea arose that a function could have a one-to-one relationship with an area in the brain.
Aristotle claimed that the brain was just a refrigerating system, while the heart was the center of all nerves; this opinion did not have much influence in the long run. His "flow charts" for psychological processes, from the sense organs to cognition and from cognition to motor functions(sense organ---sensation---perception---cognition---memory) influence later models of language functions.
Galen(3r century BC) further developed the view that different abilities were localized in different ventricles.
From the Middle Ages to 1800:
Theoretically, the discussion of the ventricles of the brain continued. Memory was assumed to be localized in the fourth ventricle and the Italian physician Antonio Guainerio suggested in the 15th century that word sparsity and naming errors were symptoms of a disturbance of memory, caused by too much phlegm in the fourth ventricle.
In the 16th century, the theories about the ventricles were criticized by Costanzo Varolius and Andreas Vesalius, both of whom wanted to localize psychological functions in the soft substance of the brain and to stress the importance of brain volume.
In the 17th century, the school of unitarism. Descartes held the view that the soul indivisible and had its center in the pineal gland, an organ that is located in the middle of the brain. Physician Thomas Willis(1664,1672) placed the imagination in the corpus callosum(a bundle of fibers connecting the two brain hemisphere). François de la Peyronie(1741), a French surgeon, also saw the corpus callosum as the center of the soul. Unitarian theories were criticized by the anatomist Albrecht von Haller as "theories without knowledge". But they were supported by the church and the monarchy at the time, since the idea of the soul as one unit, possibly located in one central brain structure, was consistent with religious dogma.
In 1770, the German physician Johann Gesner wrote a monograph called "Speech amnesia". He saw speech disorders as a type of memory disorder, caused by inertia in the connections between the different parts of the brain. These disorders were assumed to cause difficulties in associating images or abstract ideas with linguistic signs. (the first expression of an associationism which is clearly combined with neurophysiological speculation.
In 1770, the German physician Johann Gesner wrote a monograph called "Speech amnesia". He saw speech disorders as a type of memory disorder, caused by inertia in the connections between the different parts of the brain. These disorders were assumed to cause difficulties in associating images or abstract ideas with linguistic signs. (the first expression of an associationism which is clearly combined with neurophysiological speculation.
localist views were also being expressed at this time and descriptions of personal experiences of speech and language loss were published.
To sum up, at the turn of the 19th century, both theories and knowledge about aphasia existed.
The foundations of neurolinguistics theories in the late 19th century:
Gall: the first person to localize mental faculties in the brain cortex. (localist)
After Gall: (debate between unitarists and localist---partially political)
Bouillaud and Auburtin: Jean-Baptiste Bouillaud can be seen as a link between Gall and Broca. He was Gall's student and supported him. Bouillaud found two types of speech disorders connected to brain damage: disorders of "speech movements" and disorders of "word memory". Ernest Auburtin was Bouillaud's son-in-law and introduced his ideas to the anthropological society of Paris in 1861.
Broca: Traditionally, neurolinguistics is said to have been born in 1861, when Paul Broca presented his theory, based on a patient's symptoms and the dissection of his brain. Broca's theory led to new conflicts between unitarists and localists.
Meynert: claimed that consciousness, intelligence, and memory were cortical but not localized.
Wernicke: imagined that there was a specific "language gyrus" ranging from Wernicke's area(responsible for the receptive function) to Broca's area(responsible for the expressive function). Lesions in either of these areas or in the connection between them would cause aphasia.
Lichtheim
The period after Broca, Wernicke, and Lichtheim: after Broca, Wernicke, and Lichtheim, localism and associationism became the dominant views. Until the 1920s, the holistic began to dominate.
Jackson: not interested in anatomical localization, he studied how stimuli evoke responses and how complex these responses are. He distinguished two levels of language: automatic and propositional and three levels of function: elementary reflexes, automatic actions, and intentional actions.
Freud: His theory became popular in later years, since it contained thoughts about the pragmatic influence on linguistic symptoms.
Further developments in the 20th century
The strengthening of holism: Marie, von Monakow, Head, Goldstein, Lashley, bay, and Brown
Localism and associationism
Broca: Traditionally, neurolinguistics is said to have been born in 1861, when Paul Broca presented his theory, based on a patient's symptoms and the dissection of his brain. Broca's theory led to new conflicts between unitarists and localists.
Meynert: claimed that consciousness, intelligence, and memory were cortical but not localized.
Wernicke: imagined that there was a specific "language gyrus" ranging from Wernicke's area(responsible for the receptive function) to Broca's area(responsible for the expressive function). Lesions in either of these areas or in the connection between them would cause aphasia.
Lichtheim
The period after Broca, Wernicke, and Lichtheim: after Broca, Wernicke, and Lichtheim, localism and associationism became the dominant views. Until the 1920s, the holistic began to dominate.
Jackson: not interested in anatomical localization, he studied how stimuli evoke responses and how complex these responses are. He distinguished two levels of language: automatic and propositional and three levels of function: elementary reflexes, automatic actions, and intentional actions.
Freud: His theory became popular in later years, since it contained thoughts about the pragmatic influence on linguistic symptoms.
Further developments in the 20th century
The strengthening of holism: Marie, von Monakow, Head, Goldstein, Lashley, bay, and Brown
Localism and associationism
Association is rediscovered by Geschwind
Dynamic Iocalization of function: Pavlov, Vygotsky, and Luria
The test psychological tradition
Linguists and linguistic influence on aphasiology
Dynamic Iocalization of function: Pavlov, Vygotsky, and Luria
The test psychological tradition
Linguists and linguistic influence on aphasiology
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