Vincoli biologici ed etologia sociale del linguaggio: i nuovi dati sulla corteccia uditiva

Abstract

The morphological basis of language has been regarded as the core exclusivity of human language. According to this view, we can ground such a complex function as language on anatomical basis, but on the other hand this position collides with the evidences from evolutionary biology and psychobiology, that brought the speciality of human language back to a comparative level, proving that the brain primacy of the cognitive sciences’ second phase was wrong. The model used to explain the biological nature of language regards thus the anatomical structures as a biological constraint that anchors to reality, an anatomical and functional ratchet effect rather than a guarantee of the presence of language. According to this perspective, the peripherical and central structures of language can’t be trivially seen as the “biological basis” of language but they influence its realization in a qualitative way. The aim of this work is to inquire on the biological nature of language, more precisely on the auditory cortex specialization for language. Recent research on the auditory cortex showed that it plays a central adaptive role in primates and it thus shows a functional hyperspecialization. In primates the auditory perception would be connected to a core evolutionary role: intraspecies communication. Thus, the auditory perception has a central function for highly social species like primates: to recognize the biological meaning of communicative sounds. Moreover, psychobiological and neuroscientific data showed a hypersensitivity of the human auditory cortex for linguistic sounds, with a typical activation for consonant and words belonging to native language. This data would support the idea of an exaptation of the human auditory cortex for linguistic purposes, an exaptation grounded on an anatomical structure which has been originally selected for communication.