Affective Responses in Marmosets Elicited by Music and Musical Tempo Changes

Abstract

Music pervades the human existence, but much remains unknown about its evolutionary origins. A key question for understanding the evolution of music perception is whether nonhuman primates (NHPs), our evolutionary relatives, can respond to various elements of music. A common musical element and target of study in humans is tempo, which has been shown to modulate humans’ affective states, as measured by physiological markers including heart rate and heart rate variability (HRV). Studies on tempo perception in NHPs have largely relied on behavioral responses to music rather than physiological markers of affective state. In the present study, we sought to extend our understanding of music perception in NHPs by looking at tempo’s effects on physiological measures of affective state in the common marmoset, Callithrix jacchus, a New World primate. We measured heart rate responses to silence vs. playback of 4 different musical tempo conditions of the Pachelbel Canon in D. Our results reveal that musical playback can modulate marmoset affective state relative to silence, different tempos can differentially modulate heart rate and during playback, and on a shorter timescale of just seconds, changes to the note values presented in different segments of the piece can have differential effects across both heart rate measures. Altogether, these findings suggest that some aspects of tempo perception are also present in our NHP relatives. This finding points to the potential of either a common evolutionary perceptual domain from which humans and marmosets both evolved tempo perception capabilities, or a common selective pressure on both vocal species that led to the convergent evolution of similar tempo processing mechanisms in humans and marmosets.