Rhythmic entrainment: Why humans want to, fireflies can’t help it, pet birds try, and sea lions have to be bribed

Abstract

Until recently, the literature on rhythmic ability took for granted that only humans are able to synchronize body movements to an external beat-to entrain. This assumption has been undercut by findings of beat-matching in various species of parrots and, more recently, in a sea lion, several species of primates, and possibly horses. This throws open the question of how widespread beat-matching ability is in the animal kingdom. Here we reassess the arguments and evidence for an absence of beat-matching in animals, and conclude that in fact no convincing case against beatmatching in animals has been made. Instead, such evidence as there is suggests that this capacity could be quite widespread. Furthermore, mutual entrainment of oscillations is a general principle of physical systems, both biological and nonbiological, suggesting that entrainment of motor systems by sensory systems may be a default rather than an oddity. The question then becomes, not why a few privileged species are able to beat-match, but why species do not always do sowhy they vary in both spontaneous and learned beatmatching. We propose that when entrainment is not driven by fixed, mandatory connections between input and output (as in the case of, e.g., fireflies entraining to each others' flashes), it depends on voluntary control over, and voluntary or learned coupling of, sensory and motor systems, which can paradoxically lead to apparent failures of entrainment. Among the factors that affect whether an animal will entrain are sufficient control over the motor behavior to be entrained, sufficient perceptual sophistication to extract the entraining beat from the overall sensory environment, and the current cognitive state of the animal, including attention and motivation. The extent of entrainment in the animal kingdom potentially has widespread implications, not only for understanding the roots of human dance, but also for understanding the neural and cognitive architectures of animals.

Editorial: The Evolution of Rhythm Cognition: Timing in Music and Speech

“…Some review papers have properly focused on the evolutionary origins of musical rhythm and animal species showing human-like rhythmic traits (Bannan, 2016; Iversen, 2016; Wilson and Cook, 2016). Bannan (2016) provided a recount of Charles Darwin's thoughts on music and how he thought human musicality may have emerged via sexual selection.…”

“…Iversen (2016) summarized and compared many evolutionary hypotheses on the origins of rhythm in humans. Wilson and Cook (2016) discussed which animal species are capable of synchronizing to a beat, either spontaneously or after being trained, and how this evidence relates to evolutionary hypotheses. Some of these evolutionary hypotheses on music and rhythm have been tested via genetics (Mosing et al, 2015), behavioral experiments (Miani, 2016), electrophysiology (Bouwer et al, 2016) or animal comparative work (ten Cate et al; van der Aa et al, 2015).…”

Predictive and tempo-flexible synchronization to a visual metronome in monkeys

“…Because humans and parrots share the rare ability to imitate complex sounds 9 , the evolution of vocal learning might develop auditory-motor connections in the brain that are necessary for predictive and tempo-flexible synchronization 10–12 . However, a challenge to this “vocal learning and rhythmic synchronization” hypothesis is the finding that a putative vocal non-learning animal, the California sea lion, was able to acquire the ability through reward-based training 13, 14 . This raises the possibility that the capacity for predictive and tempo-flexible synchronization is widespread in animal brains including vocal non-learners, but that only certain vocal learning species are intrinsically motivated to engage in this behaviour.…”

The Evolution of Rhythm Cognition: Timing in Music and Speech

“…Iversen (2016) summarized and compared many evolutionary hypotheses on the origins of rhythm in humans. Wilson and Cook (2016) discussed which animal species are capable of synchronizing to a beat, either spontaneously or after being trained, and how this evidence relates to evolutionary hypotheses. Some of these evolutionary hypotheses on music and rhythm have been tested via genetics (Mosing et al, 2015), behavioral experiments (Miani, 2016), electrophysiology (Bouwer et al, 2016) or animal comparative work van der Aa et al, 2015).…”

“…Some review papers have properly focused on the evolutionary origins of musical rhythm and animal species showing humanlike rhythmic traits (Bannan, 2016;Iversen, 2016;Wilson and Cook, 2016). Bannan (2016) provided a recount of Charles Darwin's thoughts on music and how he thought human musicality may have emerged via sexual selection.…”