MODELING LANGUAGE EMERGENCE BY WAY OF WORKING MEMORY

摘要

One idea on the origin of language is that a key element, if not the most crucial,was the availability of neural circuits in the brain for working memory (Aboitiz,1995; Aboitiz, Garcia, Bosman, & Brunetti, 2006), the kind of of short-term mem-ory theorized by Baddeley (1992). The neural connections working memory re-lies upon are those that the language network relies upon as well, namely theextensive connections between temporoparietal and prefrontal areas. Within thissystem Francisco Aboitiz and his collaborators consider phonological workingmemory as being of paramount importance in language evolution, suggesting thatit originated as a working memory device involved in the imitation of differentvocalizations. However, it is only a small part of the role working memory playsin human language. A brain ready for language may have evolved by virtue of anexpanding working memory capacity, which allowed not only the processing ofcomplex sequences of sounds, but the ability to keep under attention the semanticmeanings of these sounds as they were being formulated as well as the posing ofconstraints for the emergence of syntactic processes. One of the first forms of em-bryonic syntax is the association of a word denoting an object with another worddenoting a predicate of the object referred to by the other word. The gap betweena purely lexical association between sound and meaning and this syntactic abilityis well demonstrated by the documented difficulties children have in acquiring ad-jectives (Sandhofer & Smith, 2007). The attempt done with the proposed modelis to contrast the early learning of names and adjectives, in a sufficient realisticmodel of the human cortex, and to compare the conceptual representation spaces,with or without the availability of a prefrontal working memory loop.