Neurostimulation improves reading and alters communication within reading networks in dyslexia

Abstract

The left temporo-parietal cortex (TPC) is critical for phonological decoding during reading and appears hypoactive in dyslexia. Therefore, a promising approach to alleviate phonological deficits in dyslexia is to modulate left TPC functioning. However, it is unclear how neurostimulation alters activity and network interactions in dyslexia. To address this gap, we combined facilitatory transcranial magnetic stimulation (TMS) to the left TPC in adults with dyslexia with an overt word and pseudoword reading task during fMRI. We found TMS-induced improvements in pseudoword reading, reduced contributions of right-hemispheric regions during reading and substantial changes between the core reading nodes and an extended network involving the right cerebellum. Stronger coupling between temporo-occipital and frontal cortices was further directly linked to improvements in pseudoword reading. Collectively, we provide evidence for the crucial role of the left TPC for phonological decoding and show that TMS can successfully modulate reading networks to improve reading in dyslexia.