Neuroanatomy of developmental dyslexia: Pitfalls and promise

Are children with developmental dyslexia all the same? A cluster analysis with more than 300 cases

“…The application of the cognitive approach in explaining DD has proved valuable with reports of word length effects and visual impairments in DD (Dehaene, Cohen, Morais, & Kolinsky, ; Gabay, Dundas, Plaut, & Behrmann, ; Provazza, Adams, Giofre, & Roberts, ; Provazza, Giofre, Adams, & Roberts, ). Furthermore, similar brain abnormalities (e.g., left vOT) have been noted across multiple methods including total brain volume, voxel‐ and surface‐based morphometry, white matter, diffusion imaging, brain gyrification, and tissue metabolite (for review, see Ramus et al, ). Consequently, an association seems to exist between the neural bases of dyslexia and visual and phonological impairments.…”

“…It should be noted, however, that in this context, the phonological subtype includes all DD who present with a deficit in verbal abilities, not only those described as phonological dyslexics in the DRC model. Depending on the neuroanatomical bases (D'Souza & Karmiloff‐Smith, ; Ramus et al, ), the point one falls along the continuum may determine the unique features present in the dyslexic profile. Recent evidence from children with specific learning disabilities shows that different cognitive clusters are apparent in this group (Poletti, Carretta, Bonvicini, & Giorgi‐Rossi, ).…”

“…The application of the cognitive approach in explaining DD has proved valuable with reports of word length effects and visual impairments in DD (Dehaene, Cohen, Morais, & Kolinsky, 2015;. Furthermore, similar brain abnormalities (e.g., left vOT) have been noted across multiple methods including total brain volume, voxel-and surface-based morphometry, white matter, diffusion imaging, brain gyrification, and tissue F I G U R E 1 (a) DRC model (e.g., Coltheart and al., 2001) and (b) Triangle model (e.g., Seidenberg & McClelland, 1989;Plaut, McClelland, Seidenberg, & Patterson, 1996) metabolite (for review, see Ramus et al, 2018). Consequently, an association seems to exist between the neural bases of dyslexia and visual and phonological impairments.…”

“…Depending on the neuroanatomical bases (D'Souza & Karmiloff-Smith, 2017;Ramus et al, 2018), the point one falls along the continuum may determine the unique features present in the dyslexic profile. Recent evidence from children with specific learning disabilities shows that different cognitive clusters are apparent in this group (Poletti, Carretta, Bonvicini, & Giorgi-Rossi, 2018).…”

Relying on brain rhythms for improving the diagnosis of dyslexia

“…Overall, although neuroimaging facilities have enhanced our understanding of the dyslexic brain, in terms of its anatomical distinctive features and the way in which it processes sounds and visual cues during reading tasks, most of the purported brain differences between dyslexic and normal reading individuals are difficult to replicate, particularly, because they result from small-scale studies; in fact, meta-analyses and large-scale studies have found that the only robust structural difference between groups is a smaller brain volume in dyslexics (Ramus, Altarelli, Jednoróg, Zhao, & Scotto di Covella, 2017).…”