Periodic Reporting for period 1 - PHYLOMUSIC (Neural encoding of novel and familiar proto-musical patterns in humans and monkeys)
Reporting period: 2023-02-01 to 2025-07-31
Music perception is a universal human capacity that relies on the brain’s ability to form expectations about upcoming sounds. These predictive mechanisms depend on tracking sequential patterns in time (rhythm) and frequency (pitch). Yet, the evolutionary and developmental origins of these processes remain poorly understood. To what extent are rhythm and melody tracking present at birth, and are they shared with our primate relatives? Addressing these questions provides insights into the biological foundations of human musicality and informs our understanding of communication, learning, and social interaction.
The overall objective of this project was to investigate the neural encoding of musical expectations in non-human primates and human newborns. By combining electroencephalography (EEG), pupillometry, and computational models of statistical learning, we examined whether these groups—both musically inexperienced—form predictions when exposed to structured musical sequences. This comparative approach aimed to identify evolutionarily conserved capacities, ontogenetic trajectories, and species-specific specialisations in music processing. Ultimately, the project contributes to a deeper understanding of predictive coding in the brain and its role in sensory perception and learning. The pathway to impact lies in informing education practices (e.g. music-based interventions in early development) and in shaping cultural and policy debates about the biological roots of music.
The overall objective of this project was to investigate the neural encoding of musical expectations in non-human primates and human newborns. By combining electroencephalography (EEG), pupillometry, and computational models of statistical learning, we examined whether these groups—both musically inexperienced—form predictions when exposed to structured musical sequences. This comparative approach aimed to identify evolutionarily conserved capacities, ontogenetic trajectories, and species-specific specialisations in music processing. Ultimately, the project contributes to a deeper understanding of predictive coding in the brain and its role in sensory perception and learning. The pathway to impact lies in informing education practices (e.g. music-based interventions in early development) and in shaping cultural and policy debates about the biological roots of music.
Two core studies were conducted. In the first, rhesus macaques with no prior exposure to music were presented with J.S. Bach’s melodies while EEG and pupillometry were recorded.
Through multivariate temporal response function analysis, neural responses revealed that monkeys generated expectations when listening to real music but not to shuffled controls. Critically, their expectations were based on timing regularities rather than pitch. Pupil dilation further indicated higher engagement during structured music.
In the second study, we tested 49 human newborns exposed to the same musical materials. We showed that newborns, like monkeys, neurally encode rhythmic but not melodic expectations. Real music, but not shuffled sequences, elicited predictive responses. Event-related potential analyses confirmed sensitivity to temporal but not pitch-based surprise. Together, these findings demonstrate that the ability to extract and predict rhythmic structures from music is present at birth and likely phylogenetically conserved, while melodic tracking emerges later through enculturation and experience.
Main achievements include:
• Establishing a fully automatized methodological pipeline that integrates EEG denoising and computational modelling to study predictive processing in naturalistic music and noisy data such as those from macaques and infants.
• Demonstrating for the first time that musically naïve monkeys encode timing-based but not melodic-based expectations in continuous music.
• Providing the first neurophysiological evidence that during naturalistic music listening, human newborns generate statistical rhythmic expectations but not melodic ones.
• Identifying a cross-species dissociation between rhythm and pitch that informs theories of the evolution and development of musicality.
Through multivariate temporal response function analysis, neural responses revealed that monkeys generated expectations when listening to real music but not to shuffled controls. Critically, their expectations were based on timing regularities rather than pitch. Pupil dilation further indicated higher engagement during structured music.
In the second study, we tested 49 human newborns exposed to the same musical materials. We showed that newborns, like monkeys, neurally encode rhythmic but not melodic expectations. Real music, but not shuffled sequences, elicited predictive responses. Event-related potential analyses confirmed sensitivity to temporal but not pitch-based surprise. Together, these findings demonstrate that the ability to extract and predict rhythmic structures from music is present at birth and likely phylogenetically conserved, while melodic tracking emerges later through enculturation and experience.
Main achievements include:
• Establishing a fully automatized methodological pipeline that integrates EEG denoising and computational modelling to study predictive processing in naturalistic music and noisy data such as those from macaques and infants.
• Demonstrating for the first time that musically naïve monkeys encode timing-based but not melodic-based expectations in continuous music.
• Providing the first neurophysiological evidence that during naturalistic music listening, human newborns generate statistical rhythmic expectations but not melodic ones.
• Identifying a cross-species dissociation between rhythm and pitch that informs theories of the evolution and development of musicality.
These findings go beyond prior work in several respects. Previous infant and primate studies focused on isolated features or simple sequences, whereas we used ecologically valid music and sophisticated brain-music interaction modelling. We show that rhythmic predictive processing is both evolutionarily ancient and developmentally precocious, whereas melodic predictions are either absent or delayed. This dissociation refines current models of music cognition, which often focus on one or the other dimension of music.
The results also highlight the need for further research into how pitch expectations develop with experience and cultural exposure, how temporal expectations support language and social interaction, and how predictive coding mechanisms can be leveraged in clinical interventions. Uptake pathways include:
• Extending studies to older infants to map developmental timelines.
• Exploring comparative work with other primates and vocal learning species.
• Translating methods to clinical populations (e.g. patients with impaired predictive processing, such as in dementia or language disorders).
The results also highlight the need for further research into how pitch expectations develop with experience and cultural exposure, how temporal expectations support language and social interaction, and how predictive coding mechanisms can be leveraged in clinical interventions. Uptake pathways include:
• Extending studies to older infants to map developmental timelines.
• Exploring comparative work with other primates and vocal learning species.
• Translating methods to clinical populations (e.g. patients with impaired predictive processing, such as in dementia or language disorders).