Seki Yoshimasa, Tomyta Kenta
Department of Psychology, Aichi University, Machihatacho, Toyohashi, Aichi, Japan.
Curr Zool. 2019 Feb;65(1):121-128. doi: 10.1093/cz/zoy075. Epub 2018 Oct 24.
The origin of rhythmic synchronization or entrainment to a musical beat in animals has been widely discussed. Parrots are suitable animals to examine the relationship between the capability of vocal learning and spontaneous rhythmic synchronization. In this study, budgerigars 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 using almost the same method. In contrast to the birds, a number of human subjects synchronized tap timing to the onset 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 examinations of the evolutionary foundations of beat processing.
动物对音乐节拍的节律同步或夹带现象的起源已得到广泛讨论。鹦鹉是研究声乐学习能力与自发节律同步之间关系的合适动物。在本研究中，虎皮鹦鹉学会以自定节奏交替敲击（啄）两个按键。然后，在测试环节中，当鸟儿执行按键啄击任务时，节拍器的声音会在背景中播放，尽管它们并不需要将敲击时间与节拍器同步。我们发现节拍器节奏对一些受试动物的敲击时间有适度但显著的影响。我们还用几乎相同的方法测试了人类。与鸟类不同，许多人类受试对象在没有言语或书面指示的情况下，将敲击时间与节拍器的节拍同步。然而，我们未能在一些人类受试对象中发现节拍器对自定节奏敲击时间的影响，尽管他们有节律同步的能力。这是第一份描述节拍器声音对非人类声乐学习者自定节奏敲击影响的报告。本研究引入了一种新方法，可用于未来的研究，以比较在声乐学习能力、社会结构、年龄、性别、激素状态等方面存在差异的鸟类，作为节拍处理进化基础研究的一部分。
