Humans enter the world with an innate ability to predict rhythmic patterns in music, but the capacity to understand melody must be learned over time, according to new research published in PLOS Biology.
A team of scientists led by the Italian Institute of Technology played piano compositions by J.S. Bach to 49 newborn babies to test their musical aptitudes. Using electroencephalography (EEG) to monitor brain activity while the infants slept, the researchers found that the newborns could track statistical regularities in rhythm.
“We observed encoding of probabilistic rhythmic expectations only in response to real but not shuffled music,” the authors write. “This proves newborns’ ability to rely on rhythmic statistical regularities to generate musical expectations”.
The biological toolkit
To isolate these skills, the researchers exposed the infants to both original Bach melodies and “shuffled” versions where the pitch and timing were scrambled to disrupt musical regularities.
The brain data revealed that while the babies were sensitive to the beat, they were effectively ‘tone deaf’ to the melodic structure. The study found “no evidence for the tracking of melodic information,” suggesting that the brain “downweight[s]” pitch compared to rhythm at this early stage of life.
“Newborns come into the world already tuned in to rhythm,” the authors explain. “This suggests that melody isn’t innate but gradually learned through exposure. In other words, rhythm may be part of our biological toolkit, while melody is something we grow into”.
Womb with a view
The study offers a biological explanation for this discrepancy. Fetal hearing is “heavily low-pass filtered” in the womb, meaning that while the rhythm of a mother’s heartbeat or gait is clearly audible, specific pitch details are muffled.
Consequently, newborns arrive with a sophisticated sensitivity to time but an immature auditory cortex regarding frequency.
The findings also align with evolutionary biology. The researchers note that sensitivity to rhythmic patterns has been observed in non-human primates, suggesting it has deep phylogenetic roots. In contrast, the processing of melody appears to be a uniquely human trait that requires cultural exposure to develop.
