Longer Fixation Times During Reading Are Correlated With Decreased Connectivity in Cognitive-Control Brain Regions During Rest in Children

Localized alterations in cortical thickness and sulcal depth of the cingulo-opercular network in relation to lower reading fluency skills in children with dyslexia

The traditional models of reading development describe how language processing and word decoding contribute to reading comprehension and how impairments in word decoding, a defining feature of dyslexia, affect reading comprehension outcomes. However, these models do not include word and sentence reading (contextual reading) fluency, both of which engage executive functions, with notably decreased performance in children with dyslexia. In the current study, we compared cortical thickness and sulcal depth (CT/SD) in the cingulo-opercular (CO) executive functions brain network in children with dyslexia and typical readers and examined associations with word vs. contextual reading fluency. Overall, CT was lower in insular regions and higher in parietal and caudal anterior cingulate cortex regions in children with dyslexia. Children with dyslexia showed positive correlations between word reading fluency and CT/SD in insular regions, whereas no significant correlations were observed in typical readers. For sentence reading fluency, negative correlations with CT/SD were found in insular regions in children with dyslexia, while positive correlations with SD were found in insular regions in typical readers. These results demonstrate the differential relations between word and sentence reading fluency and anatomical circuitry supporting executive functions in children with dyslexia vs. typical readers. It also suggests that word and sentence reading fluency, relate to morphology of executive function-related regions in children with dyslexia, whereas in typical readers, only sentence reading fluency relates to morphology of executive function regions. The results also highlight the role of the insula within the CO network in reading fluency. Here we suggest that word and sentence reading fluency are distinct components of reading that should each be included in the Simple View of Reading traditional model.

An executive-functions-based reading training enhances sensory-motor systems integration during reading fluency in children with dyslexia

The Simple View of Reading model suggests that intact language processing and word decoding lead to proficient reading comprehension, with recent studies pointing at executive functions as an important component contributing to reading proficiency. Here, we aimed to determine the underlying mechanism(s) for these changes. Participants include 120 8- to 12-year-old children (n = 55 with dyslexia, n = 65 typical readers) trained on an executive functions-based reading program, including pre/postfunctional MRI and behavioral data collection. Across groups, improved word reading was related to stronger functional connections within executive functions and sensory networks. In children with dyslexia, faster and more accurate word reading was related to stronger functional connections within and between sensory networks. These results suggest greater synchronization of brain systems after the intervention, consistent with the "neural noise" hypothesis in children with dyslexia and support the consideration of including executive functions as part of the Simple View of Reading model.

Eye-Movements in a Text Reading Task: A Comparison of Preterm Children, Children with Dyslexia and Typical Readers

Preterm birth is associated with weaknesses in reading skills that are usually less severe than those of children with dyslexia. To understand the characteristics of reading processes in preterm children, we adopted a cross-population and multi-modal approach comparing eye movements in reading tasks among three groups: children with preterm birth, children with a diagnosis of dyslexia, and children with typical development. The study involved 78 participants (10.5 years). Eye movements (number and duration of fixations, amplitude and number of saccades, number of regressions) were recorded during the silent reading of two texts; cognitive and reading standardized tasks were also administered. Children with dyslexia had more fixations and more frequent and smaller saccades compared to the preterm group and children with typical development. They also showed more regressions compared to the control group. Preterm children showed shorter fixations compared to the other groups. Cognitive and reading standardized tasks confirmed severe delays in reading in children with dyslexia and some weaknesses in text reading speed and comprehension in preterm children. These results are discussed with reference to candidate mechanisms that underlie reading processes in preterm children and considering possible implications for research.

A Systematic Review of MRI Neuroimaging for Education Research

This study aims to disclose how the magnetic resonance imaging (MRI) neuroimaging approach has been applied in education studies, and what kind of learning themes has been investigated in the reviewed MRI neuroimaging research. Based on the keywords “brain or neuroimaging or neuroscience” and “MRI or diffusion tensor imaging (DTI) or white matter or gray matter or resting-state,” a total of 25 papers were selected from the subject areas “Educational Psychology” and “Education and Educational Research” from the Web of Science and Scopus from 2000 to 2019. Content analysis showed that MRI neuroimaging and learning were studied under the following three major topics and nine subtopics: cognitive function (language, creativity, music, physical activity), science education (mathematical learning, biology learning, physics learning), and brain development (parenting, personality development). As for the type of MRI neuroimaging research, the most frequently used approaches were functional MRI, followed by structural MRI and DTI, although the choice of approach was often motivated by the specific research question. Research development trends show that the neural plasticity theme has become more prominent recently. This study concludes that in educational research, the MRI neuroimaging approach provides objective and empirical evidence to connect learning processes, outcomes, and brain mechanisms.

Greater reading gain following intervention is associated with low magnetic resonance spectroscopy derived concentrations in the anterior cingulate cortex in children with dyslexia

BACKGROUND/OBJECTIVE

The "neural noise" hypothesis suggests that individuals with dyslexia have high glutamate concentrations associated with their reading challenges. Different reading intervention programs have showed low GLX (a combined measure for glutamine and glutamate obtained with in vivo magnetic resonance spectroscopy) in association with reading improvement. Several studies demonstrated improved reading and increased activation in the anterior cingulate cortex following an-executive-function (EF)-based reading intervention. The goals of the current study are two-fold: 1) to determine if the effect of the EF-based reading program extends also to the metabolite concentrations and in particular, on the GLX concentrations in the anterior cingulate cortex; 2) to expand the neural noise hypothesis in dyslexia also to neural networks supporting additional parts of the reading networks, i.e. in specific regions related to executive function skills.

METHODS

Children with dyslexia and typical readers were trained on the EF-based reading program. Reading ability was assessed before and after training while spectroscopy data was obtained at the end of the program. The association between change in reading scores following intervention and GLX concentrations was examined.

RESULTS

Greater "gains" in word reading were associated with low GLX, Glu, Cr, and NAA concentrations for children with dyslexia compared to typical readers.

CONCLUSIONS

These results suggest that the improvement reported following the EF-based reading intervention program also involved a low GLX concentration, as well as additional metabolites previously associated with better reading ability (Glx, Cr, NAA) which may point at the decreased neural noise, especially in the anterior cingulate cortex, as a possible mechanism for the effect of this program.