Investigating the human-specificity of synchronization to music

One universal of human music perception is the tendency to move in synchrony with a periodic beat (e.g., in dance). This response is not commonly observed in nonhuman animals, raising the possibility that this behavior relies on brain circuits shaped by natural selection for music. Consequently, if a nonhuman animal can acquire this ability, this would inform debates over the evolutionary status of music. Specifically, such evidence would suggest that this ability did not originate as an evolutionary adaptation for music. We present data from an experimental study of synchronization to music in a Sulphur-crested cockatoo (Cacatua galerita eleanora), “Snowball”, who spontaneously dances in response to certain music (see YouTube: “dancing cockatoo”). Snowball’s preferred song was presented at different tempi (original, +/2.5%, 5%, 10%, 15%, and 20%), and his rhythmic movements while dancing were quantified from video. The results reveal occasional bouts of synchronization at a subset of these tempi on ~20% of the trials. This demonstrates that a nonhuman animal can synchronize to a musical beat, though with limited reliability and tempo flexibility. These findings are consistent with the “vocal learning and rhythmic synchronization” hypothesis, which suggests that vocal learning provides the auditory-motor foundation for synchronization to a musical beat.