This week’s top neuroscience news brings a fascinating discovery about how exposure to different kinds of music influences the brain’s interpretation of rhythm. A study led by researchers at MIT and the Max Planck Institute for Empirical Aesthetics, conducted in 15 countries, reveals that the human brain is biased toward hearing and producing rhythms composed of simple integer ratios.
The study, which included 39 groups of participants from diverse societies, found that the favored ratios can vary significantly across different cultures. The lead author of the study, Nori Jacoby, notes, ‘Our study provides the clearest evidence yet for some degree of universality in music perception and cognition, in the sense that every single group of participants that was tested exhibits biases for integer ratios. It also provides a glimpse of the variation that can occur across cultures, which can be quite substantial.’
According to the researchers, the brain’s bias toward simple integer ratios may have evolved as a natural error-correction system to maintain a consistent body of music, which is often used by human societies to transmit information. Josh McDermott, an associate professor of brain and cognitive sciences at MIT, explains, ‘When people produce music, they often make small mistakes. Our results are consistent with the idea that our mental representation is somewhat robust to those mistakes, but it is robust in a way that pushes us toward our preexisting ideas of the structures that should be found in music.’
The study, published in Nature Human Behaviour, involved scientists from more than two dozen institutions worldwide. It builds upon a smaller analysis conducted in 2017, where rhythm perception in groups of listeners from the United States and the Tsimane’, an Indigenous society located in the Bolivian Amazon rainforest, was compared.
To measure how people perceive rhythm, the researchers devised a task in which they played a randomly generated series of four beats and then asked the listener to tap back what they heard. The findings provide valuable insights into the influence of music on the human brain and the variations in rhythm perception across different cultures.
