Development of auditory and spontaneous movement responses to music over the first postnatal year

Abstract Humans across cultures not only share the ability to recognise music but also respond to it through movement. While the sensory encoding of music is well-studied, when and how infants naturally start moving to music is largely unexplored. This study simultaneously investigates infants’ neural (auditory) responses and spontaneous movements to music during the first postnatal year. Neural activity (EEG) and body kinematics (markerless pose estimation) were recorded from 79 infants (aged 3, 6, and 12 months) listening to refrains of children’s music, along with shuffled, high-pitched, and low-pitched versions of the same songs. Neural data revealed that, across all ages, infants exhibit enhanced auditory responses to music compared to shuffled music, indicating that auditory encoding of music emerges early in development. Movement data revealed a different outcome. While coarse auditory-motor coupling is present at all ages, more complex structured movement patterns emerge in response to music only by 12 months. Notably, no age group demonstrated evidence of coordinated movements to music. Additionally, enhanced auditory responses to high vs low pitch were only evident at 6 months, while infants’ movements were better predicted by high-pitched compared to low-pitched music at all ages. This study provides initial insights into how the developing brain gradually transforms music into spontaneous movements of increasing complexity. eLife digest Most people, no matter where they grow up, enjoy listening to music – and many instinctively move their bodies to it. This universal behavior raises a fascinating question: when does the brain first respond to music, and how does that ability develop? Babies are born with a natural sensitivity to sound. Their brains can already detect patterns in what they hear, such as repeated rhythms and melodies. Scientists can measure this brain activity using an EEG (electroencephalography), which records electrical signals produced by the brain in response to sounds. Infants also naturally move their bodies in response to sounds around them. However, we do not fully understand when these two abilities – recognizing music and moving to it – emerge, or how they relate during the first year of life. Nguyen et al. wanted to understand how babies' brain responses to music and their spontaneous body movements to music develop during the first year of life. The researchers also asked whether pitch – high or low music sounds – affects these two responses differently, since babies are known to be drawn to high-pitched sounds.

Nguyen et al. tested 79 infants aged 3, 6, and 12 months by playing children's songs and scrambled versions of the same songs. They measured brain activity using electroencephalography (EEG) while also tracking and reconstructing full-body movements from video recordings. The results revealed that all age groups – even 3-month-olds – showed stronger brain responses to real music than to scrambled music, indicating that the brain encodes musical structure very early in life. However, only 12-month-olds spontaneously moved more to music than to scrambled music, specifically exhibiting rocking, swaying, and clapping-like movements. Importantly, no age group showed movements that were coordinated in time with the musical beat. Additionally, only 6-month-olds showed stronger brain responses to high-pitched compared to low-pitched music, while high-pitched music predicted movements at all ages. Nguyen et al. are the first to measure both brain activity and body movement simultaneously in infants this young. Their findings will be relevant to researchers studying how children develop musical and movement skills, and how early rhythmic responses eventually give rise to dancing. They also provide valuable insights for caregivers and early childhood educators who use music to engage and support infants. Before any practical applications can be developed, future studies should examine how music-driven movement coordination continues to develop beyond 12 months and investigate the brain pathways that link hearing music to moving – and eventually dancing – to it. Introduction Musicality – the biological predisposition to perceive, appreciate, and produce music (Honing, 2018; Trehub, 2003) – is increasingly recognised as a fundamental aspect of human nature. Numerous accounts suggest that engaging with music through movement is at the core of musicality (Honing et al., 2015; Schachner et al., 2009; Trehub et al., 2015). Functionally, such engagement can be broken down into two fundamental components of neurocognitive development: the ability to perceive and recognise music (sensory component), and the ability to produce movement responses that are temporally aligned with the musical structure, from coordinated vocalizations and percussive actions up to complex dance moves (motor component; Brown, 2022; Trehub, 2003; Trevarthen, 1999).

Despite this inherent predisposition toward music, the developmental trajectory of infants’ musicality remains largely unknown (see Nguyen et al., 2023a, for a review). While there is increasing research on infant music perception, including controlled manipulations of select musical features, we know less about the translation of perception into action, namely the ontogenesis of infants’ spontaneous movements to music (see Fujii et al., 2014; Nguyen et al., 2023b; Zentner and Eerola, 2010). Furthermore, making our understanding of music-driven motor engagement even more incomplete, no studies to date have looked at both brain activity and spontaneous body movements simultaneously, especially during the first year of life. Accordingly, how the processing of music and its features is transformed into organised motor responses remains underexplored. The sensory component of musicality, namely music perception, can be measured using electroencephalography (EEG), specifically by recording cortical auditory evoked potentials (event-related potentials [ERP]). One of these responses is the infantile P1, a phase-locked EEG positivity peaking around 200-300 ms after an auditory stimulus (Chen et al., 2016; Kushnerenko et al., 2002; Wunderlich et al., 2006). The infantile P1 has been observed in response to both musical notes and speech segments. Auditory evoked potentials, when elicited isochronously, can also be captured using frequency domain analyses (Damsma et al., 2024; Novembre and Iannetti, 2018), such as auditory steady-state responses (ASSR), which are also called steady-state evoked potentials (SSEP, e.g. Cirelli et al., 2016; Nave et al., 2022). These neural responses can provide insight into the developing auditory system and its ability to encode musical structure. Using these neurophysiological measures, prior research has shown that newborns and infants are sensitive to beat structure, pitch deviants, and tone interval regularities (Bianco et al., 2025; Edalati et al., 2023; Háden et al., 2022; Háden et al., 2015; Háden et al.,

2009; Stefanics et al., 2009; Winkler et al., 2009). Despite these promising results, the neurophysiology of early music processing – particularly its developmental trajectory – remains not fully understood. Here, our primary goal is to investigate infants’ neural encoding of music utilizing both ERP and ASSR approaches to characterize how such neural responses change across the first year of life. Another component of musicality is the capacity to move to music (motor component; Brown, 2022; Fitch, 2015; Honing et al., 2015; Trehub et al., 2015). This capacity is linked to infants not only recognising musical structure but also moving their bodies in response to it. Even though this capacity appears to develop precociously, as evidenced by the fact that even 28-35 week-old foetuses move to music (Kisilevsky et al., 2004), very few studies have systematically examined music-driven spontaneous body movements in infants. An influential paper by Zentner and Eerola, 2010 reported that infants across a large age range (from 5 to 24 months) showed more spontaneous rhythmic movements in response to classical music and children’s music compared to infant-directed speech. Importantly, their movements were not synchronized with the musical input, even though a small degree of tempo flexibility was observed (i.e. faster musical tempi evoked relatively faster movement periodicities). The lack of synchrony between music and body movements has also been reported in younger (i.e. 3-4 months old) infants listening to popular music (Fujii et al., 2014). Furthermore, another study testing 7-month-old infants reported more movement in response to (sung) playsongs compared to lullabies but did not assess movement synchrony (Nguyen et al., 2023b). Despite these initial investigations, it remains unclear when infants begin to move in response to music, which specific movements are evoked, and when these movements become coordinated with the music. Moreover, a critical limitation in existing research is the lack of a control condition to determine whether these movements are driven specifically by musical structure or reflect general motor activity in response to auditory input.

As a second goal, this study is the first to systematically test the gradual development of music-induced movements in different age groups across the first year of life. Music engages both sensory and motor systems, yet different musical features may differentially shape infants’ engagement with music. While rhythm has been widely studied in early music cognition, pitch is another salient acoustic cue that could play a role in auditory-motor engagement, particularly in infancy. High pitch is a defining feature of infant-directed speech (Fernald and Simon, 1984), among other features, such as exaggerated intonation, slower tempo, and simplified vocabulary (Fernald and Kuhl, 1987; Kuhl and Meltzoff, 1982). Similarly, infants most frequently listen to music characterized by high pitch (Costa-Giomi and Sun, 2016; Nakata and Trehub, 2011). Reflecting its prominence, high pitch is found to be one of the most prominent features thought to effectively capture (Conrad et al., 2011; Eckerdal and Merker, 2009; Trainor, 1996; Trainor and Zacharias, 1998) and guide infants' attention (Lense et al., 2022; Trainor and Desjardins, 2002). On the neural level, infants are also better at encoding pitch deviances in the high voice of polyphonic music, thus showing high voice superiority from 3 months of age (Marie and Trainor, 2013; Marie and Trainor, 2014). Taken together, these findings indicate that higher-pitch music would amplify infants’ neural responses (i.e. sensory component) in comparison to lower-pitch music. On the other hand, we know that adults move more to music with greater energy in lower frequencies (Cameron et al., 2022; Stupacher et al., 2013; Stupacher et al., 2016; Van Dyck et al., 2013). Yet, it remains unknown whether low-pitch music elicits increased movement in infants, as it does in adults, or whether infants’ attraction to high pitch also extends to enhance their motor responses.