Neurobiology of the linguistic function: a review and implications for aphasic rehabilitation

Abstract

The Wernicke-Geschwind model has been considered the main reference in regard to the neural basis of language function. Indeed, this model has been systematically used to explain and interpret different aphasic disorders. However, recent findings across several neuroimaging studies challenge the suitability of this model to explain the cerebral dynamics observed after brain damage. This paper provides a comprehensive and up-to-date review of the most recent findings on language neuroscience. Thus, a consistent body of evidence obtained from the use of various techniques (including fMRi, EEG, MEG, TMS, tDCS, among others) strongly indicates the existence of a dynamic brain network involved in language function that recruits distant brain regions across both hemispheres, hence revealing the obsoleteness of traditional approaches for a complete understanding of language dysfunction. Despite these systematic and well-stablished findings, this and other language models are still considered nowadays in the educational and clinical practice, with detrimental implications for the successful characterization and rehabilitation of aphasic patients. Taking into account the dynamic reorganization of the language neural network, the use of modern brain neuro-modulatory techniques, together with the implementation of intense speech therapy, are discussed as the first option to be considered for the successful treatment of aphasia.