NEUROLINGUISTICS

NEUROLINGUISTICS

1. Different views on the relation between brain and language.

   • Localism tries to find locations or centers in the brain for different language functions.
   • Associationism places language functions in the connections between different areas of the brain, making it possible to associate
   • Dynamic localization of function assumes that functional systems of localized subfunctions perform language functions.
   • Holistic theories (holism) consider many language functions as handled by large parts of the brain working together
   • Hierarchical or Evolution based theories stress the relation between how brain and language evolved over time in different species
   • Unitarism and equipotentiality means that all parts of the cortex have the same functional potential and that the size of a brain lesion determines the extent of the aphasia (= mass effect).

2. Some classical frameworks in neurolinguistics

   • 1) The classical view building on Broca, Wernicke, Geschwind and coworkers from the Boston Aphasia Research Center, which mainly identifies cortical centres and connections between centres, where lesions can cause different types of aphasia.
   • 2) The view of Alexander Luria where dynamic functional systems consisting of several sub-functions in different brain areas handle language functions and can be disrupted or reorganized by lesions in these areas.
   • 3) The more evolution-based, hierarchical (sometimes called more holistic) view of language processes ‘repeating evolution’ by activation from the older and deeper parts of the brain to the later developed and more specialized cortical areas. This view was proposed by John Hughlings Jackson and further developed by Jason Brown in his theory of ‘microgenesis’.

3. Research areas in neurolinguistics

   • Brain damage and language disorders
     • One tradition, mainly originating from British studies, is to use psycholinguistic models and only indirectly refer to brain localizations
     • Another tradition is to build on a traditional neurolinguistic model and try to extend parts of it to directly relate areas of the brain to specific linguistic symptoms of people with aphasia.
   • Localization of language function
     • It provides the possibility of testing hypotheses by performing reliable group experiments involving linguistic tasks with registrations of brain activity in subjects without brain damage.
   • The evolution of language and brain
     • the motor theory of speech perception
     • the development of language and brain in children
     • artificial intelligence simulation of language and communication

4. Methods in neurolinguistic research

   • Methods for measuring and visualizing brain activity
     • computed tomography (CT)
     • magnetic resonance imaging (MRI)
     • positron emission tomography (PET)
     • SPECT (single photon emission tomography)
     • electroencephalography (EEG)
     • TMS (transcranial magnetic stimulation)
   • Methods for simulating language functions and language loss using ANN
     • two main types of modelling: symbol processing (based on traditional box-andarrow models) and artificial neural network (ANN) modelling.
   • Methods for studying linguistic behaviour in neurolinguistics
     • f two ways: (i) by studying people with brain damage, and (ii) by measuring brain activation more or less directly
   • Methods and technologies in clinical and other applications
     • the Boston Diagnostic Aphasia Examination (BDAE) or Luria’s neuropsychological investigation

5. Current trends and developments

   • One important trend in neurolinguistic research is the development and use of more varied and refined ways of measuring brain activity in relation to language and communication
   • Another trend in neurolinguistics is the development and use of more varied and refined ways of measuring and analysing behaviour
   • The further development of simulation of brain and language using artificial neural networks (ANN) is a third line of development