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Fernandez-Merino, L.

Publications and source records attributed to Fernandez-Merino, L..

2 recordsLinked to original sources

Modulating Neural Tracking of Speech in Infants

Neural oscillations synchronize to the rhythmic structure of speech, a process known as cortical tracking that is thought to support speech perception and language acquisition. Individual differences in cortical tracking during infancy predict later language outcomes, yet little is known about whether this neural mechanism can be shaped by recent auditory experience early in development. Here, we tested whether brief exposure to structured musical rhythms modulates cortical tracking of speech in Spanish-Basque bilingual infants at 6 and 10 months of age. Infants listened to speech preceded by either temporally regular musical sequences that mirrored the rhythmic structure of the speech signal or rhythmically irregular musical sequences. Cortical tracking was measured using electroencephalography and quantified as speech-brain coherence in the delta and theta frequency bands. Regular musical sequences enhanced subsequent cortical tracking of speech, but the effects varied across age, language, and frequency band. In Spanish, rhythmic priming enhanced delta-band tracking at 10 months of age, whereas in Basque it enhanced theta-band tracking at both 6 and 10 months. These language-specific effects suggest that rhythmic priming interacts with the temporal properties of individual languages and infants developing linguistic experience. Together, the findings demonstrate that cortical tracking is a highly flexible neural mechanism during infancy and can be rapidly modulated by structured rhythmic input. Thus, we identify rhythmic experience as a potential pathway through which infants auditory environment shapes neural speech processing during language development.

neuroscience↗

Temporal Structure of Music Improves the Cortical Encoding of Speech

Long and short-term musical training has been proposed to improve efficiency of cortical tracking of speech, the mechanism through which brain oscillations synchronize to the acoustic temporal structure of external stimuli. Here, we study how different rhythm structures of the musical signal can guide the temporal dynamics of auditory oscillations phase-aligned to the speech envelope. For this purpose, we investigated the effects of prior exposure to rhythmically structured musical sequences on cortical tracking of speech in Basque-Spanish bilingual adults. We conducted two EEG experiments where participants were presented with sentences in Basque and Spanish preceded by musical sequences that differed in their beat structure. The beat structure of the musical sequences was created to 1) reflect and match the syllabic structure of the sentences, 2) reflect a regular rhythm but not match the syllabic structure of the sentences, and 3) follow an irregular rhythm. First, we showed that the regularity found in the rhythmic structure of music acts as a temporal guide for brain oscillations. Second, our findings suggest that not only the regularity in music is crucial but so is adjusting this regularity to optimally reflect the rhythmic characteristics of the language. Third, despite finding some differences across frequencies for each language, we still found a strong effect of rhythm regularity on cortical tracking of speech. We showed that rhythm, inherent in musical signals, guides the adaptation of brain oscillations, by adapting the temporal dynamics of the oscillatory activity to the rhythmic scaffolding of the musical signal.

neuroscience↗