Abstract
Newborn infants have been shown to extract temporal regularities from sound sequences, both in the form of learning regular sequential properties, and extracting periodicity in the input, commonly referred to as a beat. However, these two types of regularities are often indistinguishable in isochronous sequences, as both statistical learning and beat perception can be elicited by the regular alternation of accented and unaccented sounds. Here, we manipulated the isochrony of sound sequences in order to disentangle statistical learning from beat perception in sleeping newborn infants in an EEG experiment, as previously done in adults and macaque monkeys. We used a binary accented sequence that induces a beat when presented with isochronous timing, but not when presented with randomly jittered timing. We compared mismatch responses to infrequent deviants falling on either accented or unaccented (i.e., odd and even) positions. Results showed a clear difference between metrical positions in the isochronous sequence, but not in the equivalent jittered sequence. This suggests that beat processing is present in newborns. However, the current paradigm did not show effects of statistical learning, despite previous evidence for this ability in newborns. These results show that statistical learning does not explain beat processing in newborn infants.
Research highlights Sleeping newborns process musical beat.
Transition probabilities are not enough to explain beat perception in newborn infants.
No evidence of statistical learning (based on transition probabilities) without isochronous stimulation in newborns.
Results converge with previous evidence on beat perception of newborn infants.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Author details: Fleur Bouwer, email: f.l.bouwer{at}uva.nl, Henkjan Honing, email: honing{at}uva.nl, István Winkler, email: winkler.istvan{at}ttk.hu
Data Statement Preprocessed data, analysis scripts and results will be made publicly available at the OSF repository. (DOI 10.17605/OSF.IO/EFQBK)
Declarations of interest The authors declare no conflicts of interest.
Funding This work was supported by the National Research and Innovation Office of Hungary (project no. K115385 to IW). GPH was supported by the Bolyai Research Grants from the Hungarian Academy of Sciences ((BO/00523/21/2) and the New National Excellence Program of the Ministry for Innovation and Technology from the source of the National Research, Development and Innovation (ÚNKP-21-5-BME-364). FLB was supported by a VENI grant from the Dutch Research Council NWO (VI.Veni.201G.066). HH was supported by an Open Competition grant from the Dutch Research Council NWO (406.20.CW.002).
Ethics The study was carried out at the Department of Obstetrics-Gynaecology and Perinatal Intensive Care Unit, Military Hospital, Budapest, Hungary. The study was conducted in full accordance with the Declaration of Helsinki and all applicable national laws, and it was approved by the relevant ethics committee: Medical Research Council-Committee of Scientific and Research Ethics (ETT-TUKEB), Hungary.