Summary: Trained musicians exhibited an increased ability to predict rhythmic patterns over non-musicians, with more subtle differences between those trained in Japanese or Western classical music styles.
Source: University of Tokyo
A new study looks at differences between the brains of Japanese classical musicians, Western classical musicians and nonmusicians. Researchers investigated specific kinds of neural behavior in participants as they were exposed to unfamiliar rhythms and nonrhythmic patterns. Trained musicians showed greater powers of rhythmic prediction compared to nonmusicians, with more subtle differences between those trained in Japanese or Western classical music. This research has implications for studies of cultural impact on learning and brain development.
“Music is ubiquitous and indispensable in our daily lives. Music can reward us, comfort us and satisfy us emotionally,” said Project Assistant Professor Tatsuya Daikoku from the International Research Center for Neurointelligence at the University of Tokyo. “So it’s no surprise the effect of music on the brain is well-researched. However, many studies focus on Western classical music, pop, jazz, etc., whereas ours is the first study that investigates neural mechanisms in practitioners of Japanese classical music, known as gagaku.”
Many Japanese performance arts, such as in Noh or Kabuki theater, include music that does not necessarily follow a regular beat pattern as Western classical music typically does. That is, Japanese classical music sometimes expands or contracts beats without mathematical regularity. This time interval is often referred to as ma, which is an important notion throughout Japanese culture.
Daikoku and his research partner, Assistant Professor Masato Yumoto from the Graduate School of Medicine, explored how different groups of trained musicians and nonmusicians responded to different rhythm patterns. The idea was to see how musical training might influence statistical learning, the way our brains interpret and anticipate sequential information: in this case, rhythms.
The researchers recorded participants’ brain activity directly using a technique called magnetoencephalography, which looks at magnetic signals in the brain. From the data, Daikoku and Yumoto were able to ascertain that statistical learning of the rhythms took place in the left hemisphere of participants’ brains. And importantly, there was a greater level of activity in those with musical training, be it in Japanese or Western classical music.
“We expected that musicians would exhibit strong statistical learning of unfamiliar rhythm sequences compared to nonmusicians. This has been observed in previous studies which looked at responses to unfamiliar melodies. So this in itself was not such a surprise,” said Daikoku. “What is really interesting, however, is that we were able to pick out differences in the neural responses between those trained in Japanese or Western classical music.”
These differences between Japanese and Western classical musicians are far more subtle and become apparent in the higher-order neural processing of complexity in rhythm. Though it is not the case that one culture or another performed better or worse than the other, this finding does imply that different cultural upbringings and systems of education can have a tangible effect on brain development.
“This research forms part of a larger puzzle we wish to explore — that of differences and similarities between the languages and music of cultures and how they affect learning and development,” said Daikoku. “We also look into music as a way to treat developmental disorders such as language impairment. Personally, I hope to see a rejuvenation of interest in Japanese classical music; perhaps this study will inspire those unfamiliar with such music to hear and cherish this key part of Japanese cultural history.”
Funding: This work was supported by Suntory Foundation, Kawai Foundation for Sound Technology & Music and The Kao Foundation for Arts and Sciences. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
About this music and neuroscience research article
Musical Expertise Facilitates Statistical Learning of Rhythm and the Perceptive Uncertainty: A Cross-cultural Study
The brain extracts statistical regularities from sequential information around our environment. This is referred to as statistical learning (SL). Statistical learning is considered an innate function in the human brain and contributes to the brain’s development. Within the framework of predictive coding, this learning system allows us to predict a future state to minimize sensory reaction and resolve uncertainty around the world. By auditory statistical learning, over the brain’s development, humans become able to comprehend language and music. An increasing number of studies has revealed that Western-classical musical training optimizes the brain’s probabilistic model of music and enhances the accuracy of perceptive uncertainty (entropy) in newly encountered melody. No study, however, investigates how musical training modulates the probabilistic model of rhythm, and how the musical culture tunes them. The present study investigated how SL of temporal sequences with and without a beat is reflected in neural responses, and how the SL is modulated by the two types of musical training in different cultures: Western- and Japanese-classical music (i.e., Hougaku). The neural representation showed evidence that the SL effects of beat sequence were prominent in the left hemisphere. This finding was larger in Western- and Japanese-classical musicians compared with non-musicians. Further, the entropy (uncertainty) of the sequences negatively correlated with neural effects of SL, mainly in the left hemisphere of the both Western- and Japanese-classical musicians. These suggest that, regardless of musical culture, musical training may generally facilitate SL of rhythm. However, the specific neural components showed differences between groups of musicians: an earlier component, referred to as P1, represented the left lateralization for perceptive uncertainty in both groups of musicians, whereas a later component, referred to as N1, represented the left lateralization only in Japanese Classical musicians. These findings may suggest that the types of musical training differently modulate neural representation of underlying temporal SL, particularly global processing of uncertainty rather than local processing of transitional probability. The present study sheds new light on the neurophysiological account of Japanese classical music.