Dynamics of the Anatomical Changes That Occur in the Brains of Schoolchildren as They Learn to Read

Gregory Simon,Céline Lanoë,Sandrine Rossi,Arlette Pineau,Nicolas Poirel,Olivier Houdé,Amélie Lubin,Jeroen Hendrikse

doi:10.1371/journal.pone.0081789

Abstract

Although the functional brain network involved in reading for adults and children is now well documented, a critical lack of knowledge still exists about the structural development of these brain areas. To provide a better overview of the structural dynamics of the brain that sustain reading acquisition, we acquired anatomical MRI brain images from 55 children that were divided into two groups: one prior to the formal learning of reading (n = 33, 5–6 years old) and the second a few years after formal learning (n = 22, 9–10 years old). Reading performances were collected based on the “Alouette-R” test, a standardized test for reading text in French. Voxel-based morphometry analysis of gray matter showed that only the right insula volume was different between the two groups. Moreover, the reading group showed that the volumes of the left fusiform gyrus (corresponding to the well-known visual word form area, VWFA), the anterior part of the left inferior occipital gyrus and the left thalamus were significantly modulated by reading performance. This study reinforces the crucial role of the Visual Word Form Area in reading and correlation analyses performed between ROIs volumes suggesting that the VWFA is fully connected with the traditional left-hemispheric language brain network.

Highlights

To oral language, which arose over the course of human evolution, large-scale formal reading instruction in schools appeared no earlier than the end of the 19th century
A pre-lexical stage of processing occurs in the occipito-temporal junction that is strongly involved in word recognition and corresponds to the well-known Visual Word Form Area (VWFA)
Total intracranial volume (TIV = Gray Matter (GM)+white matter (WM)+CSF) and GM regions of interest (ROIs) volumes were extracted from the developmental reading fMRI meta-analysis ROIs of Houdeet al. [1] (Table 1)

Summary

Introduction

To oral language, which arose over the course of human evolution, large-scale formal reading instruction in schools appeared no earlier than the end of the 19th century. A pre-lexical stage of processing occurs in the occipito-temporal junction that is strongly involved in word recognition and corresponds to the well-known Visual Word Form Area (VWFA) The existence of such an area that is especially devoted to the processing of visual word recognition, was proposed by Dejerine, who described the first case of pure alexia [3] and was intensively studied by Dehaene et al under the name of VWFA [4,5,6]. This area, which is localized in the left fusiform gyrus at the occipito-temporal junction, was observed to be active early in the development of reading ability. The functional role of the VWFA is still under debate, because it was activated in tasks that do not engage visual word form processing [8]

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