Podcast Interview: Thalia Wheatley & Beau Sievers

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Podcast Interview: Thalia Wheatley & Beau Sievers. PNAS: I'm your host Prashant Nair and welcome back to Science Sessions. Across time and cultures, music ...
Podcast Interview: Thalia Wheatley & Beau Sievers PNAS: I’m your host Prashant Nair and welcome back to Science Sessions. Across time and cultures, music and movement have shared a metaphorical link. People in many parts of the world express emotions through music and movement. Indeed, the relationship between the two seems so deep-seated that moods are often described using words like “bouncy” and “upbeat.” Psychologist Thalia Wheatley at Dartmouth College was fascinated when she learned that both music and movement appear to activate overlapping brain regions. Which led Wheatley to wonder whether they might share a dynamic structure. To test that theory, Wheatley and her graduate student Beau Sievers developed a computer program that would allow a user to create a short piano melody or an animated bouncing ball using a single set of parameters, such as jitter for the bouncing ball, or the amount of deviation from a tempo for the melody, and dissonance for the melody, or visual spikiness for the ball. The team then asked a group of students at Dartmouth to use the program to express emotions by creating either short clips of the melody or videos of the ball. So a piece of happy music would sound like this…whereas a piece of sad music, like this. Likewise, the animated ball would bounce differently under the sad and happy conditions. What Sievers and Wheatley found surprised them. Sievers: Our analysis consisted of comparing the musical examples people made with the movement animations that people made, and we found that they were strikingly similar. That people used the same combinations of features to express emotions in both music and movement. PNAS: That suggested that music and movement might indeed share an underlying structure. But the researchers wondered whether the finding might hold true across cultures. So they performed a similar experiment in a culturally isolated tribal village called La’ak in northeastern Cambodia, where Sievers had spent time as a volunteer. Sievers: When we went to Cambodia we hoped to perform exactly the same experiment. It turned out when we got there we were working with a group of people that had never seen computers, didn’t have a written language, were extremely culturally isolated. And we found that conducting the experiment as we’d conducted in the United States was quite difficult, and that we needed to make some modifications and simplifications to it in order to make it tractable. Wheatley: The most surprising thing to us was that we traveled literally half way around the world to the most remote place we could get to, to this tribe that had very different language than us, that had very different musical traditions, that had never seen computers before or had worn headphones, and yet it was the same result that we saw in the US. And the clarity of that cross-cultural result was somewhat of a surprise. There were differences between the cultures, but these were minor and completely swamped by the similarities.

PNAS: And yet, Sievers cautions, those findings of cross-cultural likeness in the structure of music and movement must be qualified with caveats. Sievers: Even though we found these striking similarities between the two cultures, we don’t want to say that music is a universal language. There are a lot of things that we think are universal about music, and these expressive properties, these relationships to emotion, we think, are universal. But we don’t think that that’s the only thing that music does. There’s a lot more going on in music than just this conveyance of emotion. There’s a lot of cultural variety above and beyond the universal features that we found, and we think that it’s important in science to be aware of that, to pay attention to that. PNAS: I asked Wheatley whether the findings address a longstanding debate on whether music is an evolutionary byproduct or a trait with an adaptive role. Wheatley: I think that some of the big picture implications of finding that music and movement have a common structure is that we can maybe understand for the first time why we have music, why all cultures in the world have music, that it’s not just, as Pinker would describe, auditory cheesecake, that we just use music in very adaptive ways. Many people have suggested that music establishes group synchrony or entrainment, which in turn establishes social bonding, and if you’ve ever bobbed up and down with a crowd at a large rock concert, you understand this concept. But we think that there may be other ways too that music confers adaptive benefits. We’ve shown that music in part is a recreation of human dynamic, which is why we resonate to music. And it also provides a mechanism to tune ourselves to other people, to the group because we can put on music and listen to the statistical regularities, to the structures, to the ranges of dynamics that are inherent in human movement, inherent in human speech. And so music in a sense can create a kind of social tuning exercise for us to become more of a dynamic social being. PNAS: You can find more podcasts at PNAS.org