Convergent and divergent brain structural and functional abnormalities associated with developmental dyslexia
Xiaohui Yan1, Ke Jiang1, Hui Li2
1Department of Psychology, Sun Yat-Sen University, Guangzhou, China.
Elife
|September 27, 2021
Summary
Developmental dyslexia (DD) shows consistent brain changes in the left superior temporal gyrus across languages. Language-specific differences in brain alterations highlight how DD interacts with learning different writing systems.
Area of Science:
- Neuroscience
- Developmental Psychology
- Linguistics
Background:
- Developmental dyslexia (DD) is characterized by reading difficulties.
- Previous research indicates brain network abnormalities in individuals with DD.
- Cross-linguistic variations in the neural underpinnings of DD remain unclear.
Purpose of the Study:
- To conduct a multimodal meta-analysis of structural and functional brain alterations in developmental dyslexia.
- To identify consistent and inconsistent neural signatures of DD across different languages.
- To explore the influence of language type (alphabetic vs. morpho-syllabic) on brain abnormalities in DD.
Main Methods:
- Multimodal meta-analysis integrating structural and functional neuroimaging data.
- Comparison of brain alterations across individuals with DD learning alphabetic languages and morpho-syllabic languages.
- Identification of convergent and divergent findings in grey matter volume and brain activation patterns.
Main Results:
- Convergent structural and functional alterations were found in the left superior temporal gyrus, suggesting a common neural signature for DD.
- Greater grey matter volume and activation reductions in the left inferior frontal gyrus were observed in morpho-syllabic languages compared to alphabetic languages.
- Increased brain activation and grey matter volume in certain regions suggest compensatory mechanisms.
- Language-specific reductions in activation were noted in the left middle temporal gyrus and fusiform gyrus for alphabetic languages.
Conclusions:
- The left superior temporal gyrus represents a consistent neural basis for developmental dyslexia across languages.
- Language-specific brain alterations in DD are influenced by the learning demands of different writing systems.
- Compensatory mechanisms and inconsistent findings highlight the complexity of DD's neural basis.
- This study offers cross-linguistic insights into the etiology of DD, considering both structural and functional brain changes.
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