Department of Biology and National Center for Voice and Speech, University of Utah, Salt Lake City, Utah 84112
J Neurosci. 2014 May 14;34(20):6874-8. doi: 10.1523/JNEUROSCI.0262-14.2014.
Small units of production, or modules, can be effective building blocks of more complex motor behaviors. Recording underlying movements of vocal production in awake and spontaneously behaving male Sprague Dawley rats interacting with a female, I tested whether the underlying movements of ultrasonic calls can be described by modules. Movements were quantified by laryngeal muscle EMG activity and subglottal pressure changes. A module was defined by uniformity in both larynx movement and pressure pattern that resulted in a specific spectrographic feature. Modules are produced either singly (single module call type) or in combination with a different module (composite call type). Distinct modules were shown to be linearly (re)combined. Additionally, I found that modules produced during the same expiratory phase can be linked with or without a pause in laryngeal activity, the latter creating the spectrographic appearance of two separate calls. Results suggest that combining discrete modules facilitates generation of higher-order patterns, thereby increasing overall complexity of the vocal repertoire. With additional study, modularity and flexible laryngeal-respiratory coordination may prove to be a basal feature of mammalian vocal motor control.
小的生产单元或模块可以成为更复杂运动行为的有效构建块。在与雌性互动的清醒和自发行为的雄性 Sprague Dawley 大鼠中记录发声的潜在运动，我测试了超声叫声的潜在运动是否可以通过模块来描述。运动通过喉肌肌电图活动和声门下压力变化来量化。模块通过导致特定声谱特征的喉运动和压力模式的均匀性来定义。模块要么单独产生（单一模块叫声类型），要么与不同的模块组合产生（复合叫声类型）。已经证明不同的模块可以线性地（重新）组合。此外，我发现同一呼气阶段产生的模块可以在没有喉活动暂停的情况下连接，后者会在声谱上产生两个单独叫声的外观。结果表明，组合离散的模块有助于生成更高阶的模式，从而增加了整体声音库的复杂性。随着进一步的研究，模块化和灵活的喉呼吸协调可能被证明是哺乳动物声音运动控制的基本特征。
