Reading network in dyslexia: Similar, yet different

- We used a word-rhyming task to measure differences in neural activity between dyslexics and typical readers.
- Our findings show that dyslexics and typical readers do not use the reading network similarly.
- Specifically, similar neural activation did not reflect similar behavioral performance.
- Reading performance was positively correlated with activation in the right STG and the bilateral insula only in dyslexics.
- These findings challenge the idea that normalization of neural activity is essential to remediate dyslexia.

Dyslexia is a developmental disorder characterized by reading and phonological difficulties, yet important questions remain regarding its underlying neural correlates. In this study, we used partial least squares (PLS), a multivariate analytic technique, to investigate the neural networks used by dyslexics while performing a word-rhyming task. Although the overall reading network was largely similar in dyslexics and typical readers, it did not correlate with behavior in the same way in the two groups. In particular, there was a positive association between reading performance and both right superior temporal gyrus and bilateral insula activation in dyslexic readers but a negative correlation in typical readers. Together with differences in lateralization unique to dyslexics, this suggests that the combination of poor reading performance with high insula activity and atypical laterality is a consistent marker of dyslexia. These findings emphasize the importance of understanding right-hemisphere activation in dyslexia and provide promising directions for the remediation of reading disorders.