Linking speech perception and phonology to reading disability via neural phase locking to speech

Language and reading development are intimately linked thanks to the role that phonology plays in spoken and written language. Phonological deficits likewise play a central role in developmental dyslexia. Here we examine how neural entrainment to speech, measured with electroencephalography (EEG), can provide novel insights into this relationship. We examined how EEG responses to speech relate to variability in reading and language scores, within a dataset of 713 children ages 5-18. Cerebro-acoustic phase coherence was used to quantify how well children’s EEG activity aligns to the speech contained in a 2.7 minute video. We found that neural tracking in the alpha band significantly predicted children’s reading ability, especially as it relates to nonword decoding in reading, as well as with nonword repetition, a measure of phonological short-term memory. In contrast, theta-band entrainment correlated with a separate set of oral language measures including vocabulary and grammatical development. The findings confirm the view that phase locking of neural signals to naturalistic, real-time speech is linked to language development, but also that different levels of information in the acoustic signal are used to support learning different types of these language and reading representations. Just as importantly, they suggest a way forward in understanding the link between language and reading disorders.