Structural correlates of literacy difficulties in the second language: Evidence from Mandarin-speaking children learning English.

Several neuroimaging studies have explored the neural basis of literacy difficulties in the second language (L2). However, it remains unclear whether the associated neural alterations are related to literacy abilities in the first language (L1). Using magnetic resonance imaging, we explore this issue with two experiments in Mandarin-speaking children learning English as second language. In the first experiment, we investigated children with literacy difficulties in L2 and L1 (poor in both, PB) and children with literacy difficulties only in L2 (poor in English, PE). We compared the brain structure in these two groups to a control literacy (CL) group. The results showed that the CL group had significantly less gray matter volume in the left supramarginal gyrus compared to the PB group and moderately less gray matter volume compared to the PE group. In addition, the PB group had significant greater gray matter volume in the left medial fusiform gyrus compared to the PE group and had marginally greater gray matter volume compared to the CL group. In the second experiment, we explored the relationship between the two atypical regions and literacy abilities in the two languages in an independent sample consisting of children with typical literacy. Correlation analyses revealed that the left supramarginal gyrus was significantly associated with literacy performance only in the second language, English, whereas the left medial fusiform gyrus did not correlate with the performances in either L1 or L2. Taken together, these findings suggest that literacy difficulties in an alphabetic L2 are associated with a structural abnormality in the left supramarginal gyrus, a region implicated in phonological processing, which is independent of literacy abilities in the native language.

Are children with early literacy difficulties at risk for anxiety disorders in late childhood?

The present study examined whether literacy difficulties in both grades 2 and 3 are associated with social and generalized anxiety within the school environment in grade 5 and if children with different literacy difficulties differ in anxiety levels compared to typically developing children in grade 5 after controlling for inattention. Sixty-nine Greek children with literacy difficulties and fifty-two children with typical literacy development were assessed at the beginning of grade 2 and at the end of grade 3 on standardized literacy measures (reading accuracy, text-reading fluency, reading comprehension, and spelling). In grade 5, teachers were asked to rate their children's social and generalized anxiety levels and inattentive behavior in the school context. Results of one-way ANCOVAs showed that children with literacy difficulties were experiencing more social anxiety than typically developing children. Furthermore, children with both reading and spelling difficulties, but not those with single reading or spelling difficulties, had more social anxiety. These findings suggest that there is a close connection between early literacy difficulties and social anxiety in upper elementary grades and particularly among children with both reading and spelling difficulties. Implications for both teachers and other professionals who support children's socioemotional development will be discussed.

Identifying dyslexia at the university: assessing phonological coding is not enough.

A dyslexia diagnosis in Denmark can have significant consequences for individuals, as support is not available to others with reading difficulties. Currently, the diagnosis is given solely on the basis of an electronically administered test consisting of two tasks assessing grapheme-phoneme correspondences. To examine whether the Danish diagnostic test is sufficient to identify university students with dyslexia, we compared the performance of 239 Danish university students who reported literacy difficulties and were tested for dyslexia with the Danish diagnostic test on three word-level tests (low-frequency word reading, high-frequency word reading and spelling to dictation) with the performance of separate control groups for each test: 220, 212 and 218 students, respectively. The results showed that 61% of students labelled "not dyslexic" by the Danish diagnostic test performed significantly worse than controls on at least two out of three word-level tests. In terms of self-report of literacy difficulties, students labelled "not dyslexic" by the diagnostic test were indistinguishable from those labelled "dyslexic." These findings suggest that the current method of diagnosing dyslexia in Denmark is too narrow and that adding a few simple tests of word reading and spelling would minimize the risk of overlooking students in need of literacy support.

Functional connectivity alterations associated with literacy difficulties in early readers.

The link between literacy difficulties and brain alterations has been described in depth. Resting-state fMRI (rs-fMRI) has been successfully applied to the study of intrinsic functional connectivity (iFc) both in dyslexia and typically developing children. Most related studies have focused on the stages from late childhood into adulthood using a seed to voxel approach. Our study analyzes iFc in an early childhood sample using the multivariate pattern analysis. This facilitates a hypothesis-free analysis and the possible identification of abnormal functional connectivity patterns at a whole brain level. Thirty-four children with literacy difficulties (LD) (7.1 ± 0.69 yr.) and 30 typically developing children (TD) (7.43 ± 0.52 yr.) were selected. Functional brain connectivity was measured using an rs-fMRI acquisition. The LD group showed a higher iFc between the right middle frontal gyrus (rMFG) and the default mode network (DMN) regions, and a lower iFc between the rMFG and both the bilateral insular cortex and the supramarginal gyrus. These results are interpreted as a DMN on/off routine malfunction in the LD group, which suggests an alteration of the task control network regulating DMN activity. In the LD group, the posterior cingulate cortex also showed a lower iFc with both the middle temporal poles and the fusiform gyrus. This could be interpreted as a failure in the integration of information between brain regions that facilitate reading. Our results show that children with literacy difficulties have an altered functional connectivity in their reading and attentional networks at the beginning of the literacy acquisition. Future studies should evaluate whether or not these alterations could indicate a risk of developing dyslexia.

Rhythm production at school entry as a predictor of poor reading and spelling at the end of first grade.

Rhythm plays an organisational role in the prosody and phonology of language, and children with literacy difficulties have been found to demonstrate poor rhythmic perception. This study explored whether students' performance on a simple rhythm task at school entry could serve as a predictor of whether they would face difficulties in word reading and spelling at the end of grade 1. The participants were 479 Norwegian 6-year-old first graders randomized as controls in the longitudinal RCT on track (n = 1171). Rhythmic timing and pre-reading skills were tested individually at school entry on a digital tablet. On the rhythm task, the students were told to tap a drum appearing on the screen to two different rhythms (2 Hz paced and 1.5 Hz paced). Children's responses were recorded as they tapped on the screen with their index finger. Significant group differences were found in rhythm tapping ability measured at school entry, when groups were defined upon whether children went on to score above or below the 20th percentile reading and spelling thresholds in national assessment tests at the end of grade one. Inclusion of the school-entry rhythmic tapping measure into a model of classification accuracy for above or below threshold reading and spelling improved accuracy of classification by 6.2 and 9.2% respectively.