Linguistics meets the brain: towards the source of order
Andrea Moro
IUSS, University of Pavia, Pavia Italy.
Since the second half of the XIX century, two disctinct disciplines, i.e. neuropsychology and theoretical linguistics, have accumulated different discoveries concerning human language: typically, neurophsycology on the basis of clinical and neuroanatomical pieces of evidence, proved the selective role of the left hemisphere of the human brain in language processing; on the other hand, theoretical linguistics showed that a grammatical sentence is the result of the synergy of separated modules including at least lexical semantics, (morpho)syntax and phonology.
In this talk, I will show that these independent discoveries converge in a non-trivial way. This is done by using neuroimaging techniques (in particular, Positron Emission Tomography, i.e. PET scan and fMRI) which for the first time allows to see the activation of human brain cortex in vivo. The results, based on an original methodology involving an invented language and the detection of selective errors, i.e. phonological, syntactic and morphosyntactic errors, provided evidence that the three components activate separated neural networks.
Moreover, I will show how by using neuroimaging techniques one can study language acquisition providing evidence in favor of thegenerative hypothesis that the class of human possible languages is limited by the functional architecture of the brain and roughly corresponds to a specific subset of recursive languages, that is those languages "that make an infinite use of finite means" to use von Humboldt's intuition. This will be done by using another type of invented language that includes among the rules those which do not meet the requirements attributed to Universal Grammar, that is non-recursive rules.
A further topic relates to the sources of order as displayed in the syntax of natural languages; after disproving the possibility that sequences of actions may have similarities with sequences of words and that the existence of negative sentences show that language can modulate motor control, we will approach the physical basis of language. Language consists of waves: mechanical waves of air outside our brain(sound) and electric waves inside it (neuronal network). I will show that electric waves manifest sound like shapes even in the absence of any utterances paving the road to the deciphering of the neuronal code exploited by neurons with consenquences on theoretical and applicative issues, such as the evolution of human language and the access to inner thought.
Chomsky, N. (2013) “Problems of Projection”, Lingua, Volume 130, June, pp. 33–49.
Monti, M. – Parsons, L. – Osherson, D. (2009) “The boundaries of language and thought: neural basis of inference making”, Proceedings of the National Academy of Sciences, vol. 106, n. 20, pp. 12554–12559
Moro, A. (2015) The boundaries of Babel, Second Edition, MIT Press, Cambridge, Ma.