Abstract
Strong evidence has accumulated over the past years suggesting that orthography plays a role in spoken language processing. It is still unclear, however, whether the influence of orthography on spoken language results from a co-activation of posterior brain areas dedicated to low-level orthographic processing or whether it results from orthographic restructuring of phonological representations located in the anterior perisylvian speech network itself. To test these hypotheses, we ran a fMRI study that tapped orthographic processing in the visual and auditory modalities. As a marker for orthographic processing, we used the orthographic decision task in the visual modality and the orthographic consistency effect in the auditory modality. Results showed no specific orthographic activation neither for the visual nor the auditory modality in left posterior occipito-temporal brain areas that are thought to host the visual word form system. In contrast, specific orthographic activation was found both for the visual and auditory modalities at anterior sites belonging to the perisylvian region: the left dorsal–anterior insula and the left inferior frontal gyrus. These results are in favor of the restructuring hypothesis according to which learning to read acts like a “virus” that permanently contaminates the spoken language system.
Highlights
Children learn to speak before they learn to read and write
In the present study, we combined two fMRI experiments, one in the visual modality whose purpose was to identify the brain areas involved in orthographic processing, and one in the auditory modality that looked for the cerebral bases of the orthographic consistency effect, a behavioral effect that reveals the influence of orthographic information in speech perception
We assumed that the consistency effect either resulted from on-line activation of posterior brain areas or from structural changes in the perisylvian speech network
Summary
Children learn to speak before they learn to read and write. The acquisition of spoken words is based on the development of phonological skills and the mapping of speech sounds onto meaning (e.g., Curtin and Werker, 2007). Occipito-temporal structures that have been shaped to process visual objects in the course of evolution could be recruited to process written language This is the recycling hypothesis of the left fusiform gyrus proposed by the Dehaene and Cohen (2007). According to this hypothesis, the left fusiform gyrus is in charge of the orthographic form of words and hosts the visual word form system (VWFS; Carr, 1986), known in the brain imaging literature as visual word form area (VWFA; McCandliss et al, 2003). This system processes all types of letter strings, from single letters to real words, following a postero-anterior gradient (Vinckier et al, 2007) with letter strings of higher bigram frequency being processed in a more anterior part of the fusiform gyrus than letter strings of lower bigram frequency
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
