Kobayasi Kohta I, Okanoya Kazuo
Graduate School of Science and Technology, Faculty Letters Chiba University, Japan.
Neuroreport. 2003 Mar 3;14(3):521-4. doi: 10.1097/00001756-200303030-00045.
Estrildid finches have two song types: directed (courtship) and undirected (solo). These are acoustically identical and differ only in social context. Recent studies have shown that undirected singing is accompanied by strong activation of the basal ganglia pathway, whereas directed singing is not, which suggests a different degree of feedback control between the two. We examined whether the magnitude of the Lombard effect, i.e., vocal amplitude regulation in response to environmental noise, differed based on the song context. Our results indicate that Bengalese finches change the amplitude of undirected song based on background noise levels, but do not do so for directed song. This is the first behavioral evidence suggesting that feedback control of song output vary by social context.
定向（求偶）鸣唱和非定向（独唱）鸣唱。这两种鸣唱在声学上完全相同，只是社交背景不同。最近的研究表明，非定向鸣唱伴随着基底神经节通路的强烈激活，而定向鸣唱则不然，这表明两者之间存在不同程度的反馈控制。我们研究了伦巴德效应的幅度，即对环境噪声做出反应的声音振幅调节，是否因鸣唱背景而异。我们的结果表明， Bengalese 雀会根据背景噪声水平改变非定向鸣唱的振幅，但定向鸣唱则不会。这是首个行为学证据，表明歌曲输出的反馈控制因社交背景而异。
