Neural tracking of nursery rhymes: development from infancy to early childhood and relations with vocabulary outcomes

Speech consists of regularities at different timescales. A recent discovery is that brain oscillations align their activity to modulations in the speech signal, which already occurs during infancy. The degree to which infants exhibit this neural tracking can be linked to their language development. For example, cross-sectional research demonstrates that the neural tracking of stressed syllables in sung nursery rhymes at 10 months, but not at 14 months, predicts vocabulary outcomes at 24 months (Menn et al., 2022). In another study examining 50 children, it was found that speech-brain coherence in the syllable rate at 10 months significantly predicted vocabulary at 18 months (Çetinçelik et al., 2023). This raises several questions: How does neural tracking across different frequency bands (i.e., at the phonemic, syllabic, and stress rates) develop from infancy to toddlerhood? Is neural tracking at each rate and each age predictive of children’s language outcomes? Our study seeks to confirm and expand upon existing findings by 1) examining a much larger group of neurotypical children; 2) sampling at three time intervals from early infancy into early childhood, and 3) examine long-term predictive values for vocabulary outcomes beyond infancy.