Vocal Generalization Depends on Gesture Identity and Sequence
Vocal Generalization Depends on Gesture Identity and Sequence
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DOI：
10.1523/jneurosci.5169-13.2014
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发表时间：
2014-04-16
影响因子：
5.3
通讯作者：
Sober, Samuel J.
中科院分区：
文献类型：
--
作者：
Hoffmann, Lukas A.;Sober, Samuel J.
泛化，即大脑将运动学习从一种环境转移到另一种环境的能力，发生在各种复杂的行为中。然而，人们对发声行为的泛化规则知之甚少，也不知道发声学习如何泛化到动物的整个自然发声和序列。在这里，我们询问非人类声音学习者是否发生泛化并量化其属性。我们假设对一个序列中产生的声音手势的自适应纠错可以推广到其他序列中产生的相同手势。为了检验我们的假设，我们操纵了孟加拉雀（Lonchura striata var. Domestica）听觉反馈的基频（音调），以在特定序列中产生的声音手势（歌曲音节）期间产生感觉错误。正如假设的那样，对音调变化的声音手势的纠错学习可以推广到在其他连续上下文中产生的相同手势。令人惊讶的是，泛化幅度很大程度上取决于距音调变化音节的顺序距离，对靠近音调变化音节产生的手势具有更大的适应性。另一个意想不到的结果是，非移位音节的音高与移位音节相反的方向改变。这种明显反适应性的泛化模式无法用泛化与音调音节的声学相似性之间的相关性来解释。因此，这些发现表明，泛化取决于声音手势的类型及其相对于其他手势的顺序上下文，并且可能反映了声音学习和维护的有利策略。
Generalization, the brain's ability to transfer motor learning from one context to another, occurs in a wide range of complex behaviors. However, the rules of generalization in vocal behavior are poorly understood, and it is unknown how vocal learning generalizes across an animal's entire repertoire of natural vocalizations and sequences. Here, we asked whether generalization occurs in a nonhuman vocal learner and quantified its properties. We hypothesized that adaptive error correction of a vocal gesture produced in one sequence would generalize to the same gesture produced in other sequences. To test our hypothesis, we manipulated the fundamental frequency (pitch) of auditory feedback in Bengalese finches (Lonchura striata var. domestica) to create sensory errors during vocal gestures (song syllables) produced in particular sequences. As hypothesized, error-corrective learning on pitch-shifted vocal gestures generalized to the same gestures produced in other sequential contexts. Surprisingly, generalization magnitude depended strongly on sequential distance from the pitch-shifted syllables, with greater adaptation for gestures produced near to the pitch-shifted syllable. A further unexpected result was that nonshifted syllables changed their pitch in the direction opposite from the shifted syllables. This apparently antiadaptive pattern of generalization could not be explained by correlations between generalization and the acoustic similarity to the pitch-shifted syllable. These findings therefore suggest that generalization depends on the type of vocal gesture and its sequential context relative to other gestures and may reflect an advantageous strategy for vocal learning and maintenance.