摘要
The origin of rhythmic synchronization or entrainment to a musical beat in animals has been widely discussed. Parrots are suitable animals to exami ne the relati on ship betwee n the capability of vocal learning and spontaneous rhythmic synchronization. In this study, budgerigars Melopsittacus undulatus learned to tap (peck) 2 keys alternately at a self-paced rate. Then, the metronomic sounds were played in the background during test sessions while the birds were performing the key pecking task, although they were not required to synchronize tap timing with the metronome. We found modest but significant effects of the metronome rhythms on the tap timing in some subjects. We also tested humans Homo sapiens using almost the same method. In contrast to the birds, a number of huma n subjects synchr on ized tap timing to the on set of the metronome without verbal or documented instructions. However, we failed to find an effect of the metronome on self-paced tap timing in some human subjects, although they were capable of rhythmic synchronization. This is the first report describing the effects of metronomic sounds on self-paced tapping in nonhuman vocal learners. This study introduces a new method that can be used in future research comparing birds that differ in vocal learning capacities, social structure, age, sex, hormonal status, and so on as part of exami nations of the evolutionary foun dati ons of beat processing.
