This article was originally featured in MIT Press.
In 2009, my research group made a groundbreaking discovery. We found that newborns possess the ability to discern a regular pulse–the beat–in music. It’s a skill that might seem trivial to most of us but that’s fundamental to the creation and appreciation of music. The discovery sparked a profound curiosity in me, leading to an exploration of the biological underpinnings of our innate capacity for music, commonly referred to as “musicality.”
The experiment we conducted involved playing drum rhythms, occasionally omitting a beat, and observing the newborns’ responses. Astonishingly, these tiny participants displayed an anticipation of the missing beat, as their brains exhibited a distinct spike, signaling a violation of their expectations when a note was omitted. This discovery not only unveiled the musical prowess of newborns but also helped lay the foundation for a burgeoning field dedicated to studying the origins of musicality.
But music, we discovered, is not solely a cultural phenomenon but also possesses deep biological roots, apparently offering an evolutionary advantage to our species.
Yet, as with any discovery, skepticism emerged (as it should). Some colleagues challenged our interpretation of the results, suggesting alternate explanations rooted in the acoustic nature of the stimuli we employed. Others argued that the observed reactions were a result of statistical learning, questioning the validity of beat perception being a separate mechanism essential to our musical capacity. Infants actively engage in statistical learning as they acquire a new language, enabling them to grasp elements such as word order and common accent structures in their native language. Why would music perception be any different?
To address these challenges, in 2015, our group decided to revisit and overhaul our earlier beat perception study, expanding its scope, method and scale, and, once more, decided to include, next to newborns, adults (musicians and non-musicians) and macaque monkeys.
The results, published last month in Cognition, unequivocally confirm that beat perception is a distinct mechanism, separate from statistical learning. The study provides converging evidence on newborns’ beat perception capabilities. In other words, the study was not simply a replication but utilized an alternative paradigm leading to the same conclusion, and, as such, it succeeded in dispelling any lingering doubts.
When we employed the same paradigm with macaque monkeys in 2018, we found no evidence for beat processing, only a sensitivity to the isochrony (i.e., regularity) of the rhythms. This suggests that the evolution of beat perception unfolded gradually among primates, reaching its pinnacle in humans and manifesting with limitations in other species like chimpanzees and various other nonhuman primates. It provides further empirical support for the Gradual Audiomotor Evolution (GAE) hypothesis I outlined in my 2019 book “The Evolving Animal Orchestra,” a hypothesis that addresses the similarities and differences that are found in rhythm perception (and production) between human and nonhuman primates.
