Tackling the ‘dyslexia paradox’: reading brain and behavior for early markers of developmental dyslexia

Abstract

Developmental dyslexia is an unexplained inability to acquire accurate or fluent reading that affects approximately 5–17% of children. Dyslexia is associated with structural and functional alterations in various brain regions that support reading. Neuroimaging studies in infants and pre-reading children suggest that these alterations predate reading instruction and reading failure, supporting the hypothesis that variant function in dyslexia susceptibility genes lead to atypical neural migration and/or axonal growth during early, most likely in utero, brain development. Yet, dyslexia is typically not diagnosed until a child has failed to learn to read as expected (usually in second grade or later). There is emerging evidence that neuroimaging measures, when combined with key behavioral measures, can enhance the accuracy of identification of dyslexia risk in prereading children but its sensitivity, specificity, and cost-efficiency is still unclear. Early identification of dyslexia risk carries important implications for dyslexia remediation and the amelioration of the psychosocial consequences commonly associated with reading failure.

The relationship between socioeconomic status and white matter microstructure in pre‐reading children: A longitudinal investigation

“…A confluence of genetic and environmental influences interact reciprocally to affect children's reading development (Ozernov‐Palchik, Yu, Wang, & Gaab, ). Hereditary risk is a strong predictor of reading disability, as approximately 40–60% of children who have a parent who is reading‐disabled will have reading problems themselves (Gilger, Hanebuth, Smith, & Pennington, ; Snowling, Gallagher, & Frith, ).…”

Integrating MRI brain imaging studies of pre-reading children with current theories of developmental dyslexia: a review and quantitative meta-analysis

“…Although an increasing number of studies take a network and/or a multivariate pattern analytical approach in identifying differences in dyslexia [e.g., 2], here, we deliberately take a modular perspective and focus on the location of neurobiological anomalies related to dyslexia in order to link findings with etiological theories of dyslexia. We therefore do not include electrophysiological studies, which have higher temporal resolution but typically have lower spatial resolution [for an overview of other behavioral and electroencephalography (EEG) studies see 3,4]. …”

How to create a successful reader? Milestones in reading development from birth to adolescence

“…The specific case of dyslexia demonstrates the critical role of several key EF in reading development (speed of processing, working memory and visual attention), all of which were found to be impaired in children with dyslexia (41) (42). Therefore, reports of the positive effect of EF training (43) or even video games exposure (44) on reading abilities are not surprising and may be the key for intervention or even prevention for children who are at genetic risk for developing reading difficulties, as also has been suggested by Ozrenov-Palchik and Gaab (45). In his multivariate model for dyslexia, Pennington strengthens the tight relationship between phonological processing deficits and additional cognitive alterations (i.e.…”