Movement variability can be modulated in speech production.
Movement variability can be modulated in speech production.
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运动的可变性可以在言语产生中进行调节。
DOI：
10.1152/jn.00095.2022
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发表时间：
2022
影响因子：
2.5
通讯作者：
Niziolek,CarolineA
中科院分区：
文献类型：
--
作者：
Tang,Ding-Lan;Parrell,Benjamin;Niziolek,CarolineA
虽然运动变异性通常归因于运动系统中不必要的噪声，但最近的工作表明，变异性可以被主动控制。到目前为止，对运动变异性调节的研究依赖于相对简单的实验室特定的达到任务。目前尚不清楚这些结果如何转化为复杂的，实践良好的任务。在这里，我们测试变异性是如何在言语产生过程中调节的，言语产生是一种复杂的、高度过度练习的、依赖于听觉和体感反馈的自然运动行为。具体来说，在一系列的四个实验中，我们评估了听觉反馈操作的影响，调节感知的语音变异，移动每个生产要么朝着（向内推）或远离（向外推）的中心分布的每个元音。参与者暴露于内推扰动（实验1）增加产生的变异性，而施加扰动，以及后被删除。出乎意料的是，外推扰动（实验2）也增加了暴露过程中产生的变异性，但变异性恢复到接近基线水平时，扰动被删除。外推扰动未能减少参与者产生的变异性与较大的扰动幅度（实验3）和后，他们的变异性增加了超过基线水平的结果，向内推扰动（实验4）。使用状态空间模型的电机行为的应用扰动的模拟表明，在响应于两种类型的扰动产生的变异性的增加可能会出现通过不同的机制。总之，这些结果表明，运动变异性是积极监测，可以调制，即使在复杂的和良好的实践行为，如speech.NEW & NOTEWORTHBy实施一种新的听觉反馈扰动，调制参与者的感知试验到试验的变异性，而不影响他们的整体平均行为，我们表明，在言语运动系统的变异性可以调制。通过分析言语产生，我们将我们目前对变异性的理解扩展到肢体控制系统之外的一个训练有素的复杂行为。我们的研究结果还强调了需要将主动控制的语音运动控制模型的可变性。
Although movement variability is often attributed to unwanted noise in the motor system, recent work has demonstrated that variability may be actively controlled. To date, research on regulation of motor variability has relied on relatively simple, laboratory-specific reaching tasks. It is not clear how these results translate to complex, well-practiced tasks. Here, we test how variability is regulated during speech production, a complex, highly overpracticed, and natural motor behavior that relies on auditory and somatosensory feedback. Specifically, in a series of four experiments, we assessed the effects of auditory feedback manipulations that modulate perceived speech variability, shifting every production either toward (inward pushing) or away from (outward pushing) the center of the distribution for each vowel. Participants exposed to the inward-pushing perturbation (experiment 1) increased produced variability while the perturbation was applied as well as after it was removed. Unexpectedly, the outward-pushing perturbation (experiment 2) also increased produced variability during exposure, but variability returned to near-baseline levels when the perturbation was removed. Outward-pushing perturbations failed to reduce participants’ produced variability both with larger perturbation magnitude (experiment 3) and after their variability had increased above baseline levels as a result of the inward-pushing perturbation (experiment 4). Simulations of the applied perturbations using a state-space model of motor behavior suggest that the increases in produced variability in response to the two types of perturbations may arise through distinct mechanisms. Together, these results suggest that motor variability is actively monitored and can be modulated even in complex and well-practiced behaviors such as speech.NEW & NOTEWORTHYBy implementing a novel auditory feedback perturbation that modulates participants’ perceived trial-to-trial variability without affecting their overall mean behavior, we show that variability in the speech motor system can be modulated. By assaying speech production, we expand our current understanding of variability to a well-practiced, complex behavior outside of the limb control system. Our results additionally highlight the need to incorporate the active control of variability in models of speech motor control.