EJN: What has been, in your opinion, your most exciting result or finding?
TRAINOR: Well, that is hard to answer, I’lI have to give a few! In a general sense, I think the most exciting and surprising finding is how important music is across domains, including emotional wellbeing, social interaction, and language development, as reflected in how musical people are and how music is used by caregivers around the world in their earliest interactions with babies. My research is suggesting that a large part of the power of music has to do with its temporal structure, in how it is organized over time. This affects essentially every part of what it is to be human. Everything that we experience in the world unfolds over time. You can’t stop time! And so, one of the main things that the brain needs to do is organize incoming information into meaningful units (e.g., words, melodies, actions) in real time. It’s a daunting task when you think about it. One of the ways the brain copes with this is to continually make predictions about what will happen next, so it can focus future attention optimally, and react when its predictions are not borne out. The regularity of rhythms enhances the ability to predict when future sounds are likely to occur. Rhythms are fundamental to how we move and all of our physiological systems, such as heart rate and breathing. Even cognition and social interactions are rhythmically organized. Our thoughts take place over time, and how we interact with other people takes place over time. And there’s so much exciting work now on how rhythms mediate interpersonal interactions by enabling synchronization. For me, the fundamental role of rhythm is absolutely fascinating.
One of our discoveries that I find the most interesting is that infants use interpersonal rhythmic synchrony to decide who to trust and befriend. If adults move in synchrony to music with each other, even for a short time, afterwards they like each other more, they trust each other more, and they feel more affiliated. If you give them a game to play in which they can compete or cooperate, they will cooperate more. So, movement synchrony between people has a profound effect on social relations, and the regular beat of music is the perfect stimulus for inducing movement synchrony between people. And we’ve shown that this occurs in children as young as 14 months! After being bounced to music in-sync with a stranger for only three minutes, infants are much more likely to help that stranger by picking up an object she “accidentally” dropped that she needed for a task (e.g., a clothespin to pin clothes on a line), compared to infants who were bounced out-of-sync with a stranger. To me, this is absolutely fascinating because not only do infants use musical rhythms to understand music and language, but they also use them to decide who they should trust, help and befriend in their social environment. Furthermore, our studies show that infants’ brain oscillations track the frequency (or tempo) of the basic beat in musical rhythms, as well as its metrical (grouping) structure (e.g., what differentiates a waltz from a march). And we’ve shown that this is present already in infants born two months prematurely. Thus, rhythm tracking appears to be a fundamental neural organizing principle, which might explain why deficits in rhythm and timing are associated with most developmental disorders.