Words and Meters: Neural Evidence for a Connection Between Individual Differences in Statistical Learning and Rhythmic Ability in Infancy

Music and language are both hierarchically structured: syllables combine into words, and meters are groupings of musical beats. Statistical learning (SL) supports speech segmentation through computation of transitional probabilities between syllables, and individual differences in SL ability were found predictive of further language development. The current study investigated whether rhythmic ability (RA; the ability to perceive the beat and infer the meter in a rhythmic stimulus auditory input) correlated with SL in 6- to 9-month-old infants. We further explored whether RA of the parents predicted infant RA and/or SL. We used EEG to measure infants' neural entrainment in two conditions: (1) a speech segmentation SL condition in which transitional probabilities between syllables were the only cue to segment the speech stream into words; (2) a RA condition exposing infants to a syncopated rhythm in a quadruple meter. We correlated neural entrainment to the words in the SL condition with entrainment to the meter in the RA condition. Parents completed behavioral tasks measuring their RA and were asked about their engagement with music. Results revealed a correlation between neural entrainment indexing SL and RA in infants, which was unaffected by infant age. This correlation was specific to neural entrainment to words and meters, suggesting similarity between processing items at hierarchically corresponding levels. We found no evidence that parental RA predicted infant RA or SL. However, frequency of parent-child joint musical engagement appeared to have a positive effect on infant RA.