Convergent and divergent brain structural and functional abnormalities associated with developmental dyslexia

Abstract

Brain abnormalities in the reading network have been repeatedly reported in individuals with developmental dyslexia (DD); however, it is still not totally understood where the structural and functional abnormalities are consistent/inconsistent across languages. In the current multimodal meta-analysis, we found convergent structural and functional alterations in the left superior temporal gyrus across languages, suggesting a neural signature of DD. We found greater reduction in grey matter volume and brain activation in the left inferior frontal gyrus in morpho-syllabic languages (e.g. Chinese) than in alphabetic languages, and greater reduction in brain activation in the left middle temporal gyrus and fusiform gyrus in alphabetic languages than in morpho-syllabic languages. These language differences are explained as consequences of being DD while learning a specific language. In addition, we also found brain regions that showed increased grey matter volume and brain activation, presumably suggesting compensations and brain regions that showed inconsistent alterations in brain structure and function. Our study provides important insights about the etiology of DD from a cross-linguistic perspective with considerations of consistency/inconsistency between structural and functional alterations.

Seeking Overlapping Neuroanatomical Alterations between Dyslexia and Attention-Deficit/Hyperactivity Disorder: A Meta-Analytic Replication Study

“…This stance is coherent with a recent ALE cluster-level FWE corrected study by Samea et al [ 40 ] on pediatric subjects with ADHD. By contrast, prior CBMAs described significant, albeit largely different, patterns of neuroanatomical alteration in dyslexia [ 100 , 101 , 102 ]. The discrepancy in VBM findings between current and early meta-analyses could be explained by a number of factors.…”

“…First, the CBMAs of Linkersdörfer et al [ 100 ] and Richlan et al [ 101 ] analyzed small datasets due to the limited availability of appropriate data (i.e., nine experiments for a total of 62 gray matter decrease foci and nine experiments for a total of 45 gray matter decrease/increase foci, respectively), hence prone to type I error [ 93 ]. Second, Yan et al [ 102 ] evaluated the neuroanatomical landscape of dyslexia from a cross-linguistic writing perspective, partitioning the current VBM literature about disorder in two datasets, namely the alphabetic language (21 experiments) and morpho-syllabic (6 experiments) groups. Third, Richlan et al [ 101 ] and Yan et al [ 102 ] used the effect-size version of SDM at uncorrected level; Linkersdörfer et al [ 100 ] used the ALE instead.…”

“…Second, Yan et al [ 102 ] evaluated the neuroanatomical landscape of dyslexia from a cross-linguistic writing perspective, partitioning the current VBM literature about disorder in two datasets, namely the alphabetic language (21 experiments) and morpho-syllabic (6 experiments) groups. Third, Richlan et al [ 101 ] and Yan et al [ 102 ] used the effect-size version of SDM at uncorrected level; Linkersdörfer et al [ 100 ] used the ALE instead. While these CBMA methods test the spatial convergence across coordinates, our PSI-SDM approach conducts standard univariate voxel-wise tests [ 38 , 79 ].…”

Self-Regulation of Visual Word Form Area activation with real-time fMRI neurofeedback

“…These findings are not surprising as key regions of the reading network have been found to show functional connections related to reading performance (Jasinska et al, 2021; Koyama et al, 2011). Importantly, these activity increases in additional reading-related brain regions might further enhance potential NF-driven improvements in reading performance as many of these other regions, also, have been found to show hypoactivation in individuals with poor reading skills as compared to those with typical reading skills (Martin et al, 2016; Richlan et al, 2009; Yan et al, 2021).…”

Brain responses during auditory word recognition vary with reading ability in Chinese school‐age children

“…The left TPC has been proposed to be important in both speech perception and reading because of its central role in phonological processing across languages (Cattinelli et al., 2013; Chang et al., 2010; Feng et al., 2018; Hodgson et al., 2021; Liu et al., 2009; Si et al., 2017; Yan et al., 2021). Lesions in the left TPC caused overall and non‐selective deficits in reading aloud (Dickens et al., 2021) and impeded the development of the typical neural substrate of orthography processing (Li et al., 2021).…”