History and Schools of Neuroliguistics Flashcards
(35 cards)
What is the definition of neurolinguistics?
[definition] the study of the neural mechanisms in the human brain that control the comprehension, production, and acquisition of language.
What are some methods in neurolinguistics?
- lesion studies
- positron emission tomography
- functional magnetic resonance imaging
- electroencenphalography
- magnetoencephalography
What are lesion studies, and what is the important assumption when drawing conclusion from these studies?
Looks at localization and neural architecture (system breakdown).
– injury always takes away function (never adds)
What is PET and what are it’s pros/cons?
[definition] a functional imagine technique which detects gamma radiation emitted by the tracer; a radioactive substance is injected into the blood stream and looked at with a PET scan.
[pros] good for temporal images
[cons] invasive, costly, risk of radiation to patients
What is fMRI and what are it’s pros/cons?
[definition] a functional imaging technique which detects changes in blow flow using strong magnets
– uses BOLD signals (higher O2 levels are correlated with higher neuronal activity, which occurs when there is more work being done)
[pros] good spatial resolution, non-invasive
[cons] poor temporal resolution, costly
– problems for neurolinguistics is that you can’t really get headphones into a machine due to magnetic properties
What is EEG and what are it’s pros/cons?
[definition] records electrical activity within the brain (as it is reflected along the scalp) using multiple electrodes; uses ERP as an electrophysiological response to a specific event (big ERP components: N400, P600, etc.)
[pros] good temporal accuracy, fairly affordable, non-invasive
[cons] poor spatial accuracy, and there is a possible downside in that you nearly always need to measure a disruption against ‘normal’
What is MEG and what are it’s pros/cons?
[definition] records magnetic fields produced by electrical currents that occur naturally in the brain
[pros] good spatial and temporal accuracy, non-invasive
[cons] costly – like, super costly. requires grants, costly.
What does P600 indicate?
it is an index of syntactic processing
What does N400 indicate?
it is an index of semantic processing
Who is William Wundt?
(1832 - 1920)
The founder of experimental psychology; viewed language as a mechanism to transform thought in sentence.
Who is Franz Joseph Gall?
The founder of phrenology!
– measurements of the human skull (based on the concept that the brain is the organ of the mind, and that certain brain areas have localized and specific functions or modules)
Phrenology…
- recognized uniformity and continuity of cortex
- saw the cortex as the highest level of brain organization
- looked at certain human abilities as being innate (this “surface map”); the development of the skull reflects the cortex underneath, and cranioscopy can give information about the cortex and therefore the relative representedness of the abilities
What is localism?
The idea that different “higher functions” are localized in various different “centers” of the brain (mainly the cortex).
– these centers can be seen as “sisters”, ie. equally important, or there may be a particular center that is seen as hierarchically superordinate to others (ie. the prefrontal cortex)
[Gall, Broca]
What is associationism?
The idea that higher functions are dependent on the associations (connections) between different ‘centers’ in the brain.
– aphasia results from broken connections between the centers that are needed for linguistic function
[Wernicke, Lichteim, Geschwind]
What is dynamic localization?
The idea that different linguistic (sub-)functions are seens as localized (distributed) in different parts of the brain
- in order to get more complex functions, these sub-functions must be combined (different areas combines)
- the relationship between a localized lesion and the functions/phenomena that are distributed therefore becomes much more complex
[Luria, Vygotsky]
What is the evolutionary view?
The idea that emphasizes that the structure of the human brain has developed in a layered manner from inner (lower) more primitive structures to the later developed superimposed cortical layers.
– emphasizes the role of all of these hierarchically developed layers in language and communication
- from simple to more complex
- from lower centers to higher centers
- from more organized centers to more complex centers
- from automatic to intentional
[J. H. Jackson]
What is holism?
The idea the the brain (for higher functions at least) works as a whole
- the cortex handles such things as “higher cognitive function”, “symbolic thinking”, “intelligence”, “abstraction”…
- aphasia can be taken to be a sign of general cognitive loss (not a loss that affects language specifically)
- cognitivism
- equipotentiality
[Marie, Head, Goldstein]
What is equipotentiality?
The notion that all parts of the cortex have the same functional potential (the size of brain lesions determines the extent of the aphasia)
– “unitarism”; the soul is one and cannot be devided
[Karl Lashley; behaviourism and the “apparent capacity of any intact part of a functional brain to carry out…the functions which are lost by the destruction of [other parts]”]
Who is Paul Broca?
The man who founded Broca’s area (duh).
- autopsied a patient (Tan) who could understand normal speech but could not speak or write a sentence ( = production deficit)
- could only articulate the word “tan” (real name is Leborgne)
- after autopsying eight similar patients with lesions in the LEFT FRONTAL LOBE Broca argued that we “speak with the left hemisphere”
What are Broca’s theories of language in the brain?
- language articulation lies in the third frontal convolution of the inferior frontal gyrus
- there if left hemisphere dominance in language articulation
- understanding language is a different cognitive task than producing it
- language is lateralizde
Who is Carl Wernicke?
Wernicke’s area!
– posterior part of the first/superior temporal gyrus and adjacent areas (parts of the angular gyrus, the supramarginal gyrus, and the second temporal gyrus are included)
Damage to this area disturbs language comprehension.
Wernicke imagined a specific “language gyrus” from Wernicke’s area (with receptive function) to Broca’s area (with expressive function).
– lesions in one of these areas OR in the connection between them would cause aphasia
What are the important parts of Wernicke’s theory?
- the identification of symptom complexes
- the idea about flow of information
- the idea of representation
- - Broca’s area is said to have a “motor representation” of speech, while Wernicke’s area is said to have an “auditory sound representation” of speech
What are the principles of modular language processing?
> > > ** «<
- determinism: one and only one syntactic analysis at a time
- simplicity: do not assume unnecessary structure
- seriality: complete processing in one domain before processing in another domain begins (one structure at a time)
- incrementality: process each new unit (word) when it becomes available
- immediacy: process each new unit (word) when it becomes available (do not wait)
- domain specificity: syntactic parser cares about structure building only
What are the stages of modular language processing?
- input
- lexical processor
- – categories
[stage 1]
- syntactic parser
- – syntactic structure
[stage 2]
- thematic interpreter
- – meaning
What are mental modules?
[definition] specialized processing facilities that mediate between ‘peripheral’ sensory information and ‘higher’ levels of language processing.
- support rapid online language processing
- a set of automatized functions/operations needed to construct linguistic representations in real time on the basis of rapidly changing speech signals
