Miller Cory T, Eliades Steven J, Wang Xiaoqin
Laboratory of Auditory Neurophysiology, Department of Biomedical Engineering, Johns Hopkins University, School of Medicine.
Anim Behav. 2009 Nov;78(5):1195-1203. doi: 10.1016/j.anbehav.2009.07.038.
The vocal motor plan is one of the most fundamental and poorly understood elements of primate vocal production. Here we tested whether a single vocal motor plan comprises the full length of a vocalization. We hypothesized that if a single motor plan was determined at vocal onset, the acoustic features early in the call should be predictive of the subsequent call structure. Analyses were performed on two classes of features in marmoset phee calls: continuous and discrete. We first generated correlation matrices of all the continuous features of phee calls. Results showed that the start frequency of a phee's first pulse significantly correlated with all subsequent spectral features. Moreover, significant correlations were evident within the spectral features as well as within the temporal features, but there was little relationship between these measures. Using a discrete feature, 'the number of pulses in the phee call', a discriminant function was able to correctly classify the number of pulses in the calls well above chance based solely on the acoustic structure of the call's first pulse. Together, these data suggest that a vocal motor plan for the complete call structure is established at call onset. These findings provide a key insight into the mechanisms underlying vocal production in nonhuman primates.
发声运动计划是灵长类动物发声过程中最基本且了解甚少的要素之一。在此，我们测试了单一发声运动计划是否涵盖一次发声的全过程。我们假设，如果在发声开始时就确定了单一运动计划，那么叫声早期的声学特征应该能够预测后续的叫声结构。对狨猴的“phee”叫声的两类特征进行了分析：连续特征和离散特征。我们首先生成了“phee”叫声所有连续特征的相关矩阵。结果表明，“phee”叫声第一个脉冲的起始频率与所有后续频谱特征显著相关。此外，频谱特征之间以及时间特征之间也存在显著相关性，但这些测量之间几乎没有关联。使用离散特征“phee”叫声中的脉冲数，一个判别函数能够仅根据叫声第一个脉冲的声学结构，以远高于随机概率的准确率正确分类叫声中的脉冲数。总之，这些数据表明，完整叫声结构的发声运动计划在叫声开始时就已确立。这些发现为深入了解非人类灵长类动物发声的潜在机制提供了关键见解。
