Intact Correction for Self-Produced Vowel Formant Variability in Individuals With Cerebellar Ataxia Regardless of Auditory Feedback Availability.
Intact Correction for Self-Produced Vowel Formant Variability in Individuals With Cerebellar Ataxia Regardless of Auditory Feedback Availability.
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DOI：
10.1044/2021_jslhr-20-00270
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发表时间：
2021-04
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影响因子：
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通讯作者：
B. Parrell;R. Ivry;S. Nagarajan;J. Houde
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作者：
B. Parrell;R. Ivry;S. Nagarajan;J. Houde
目的小脑变性引起的小脑共济失调（cerebellar ataxia，CA）患者对意外听觉反馈扰动的反应性代偿反应比神经生物学典型的说话者大，提示他们在说话时可能更依赖反馈控制。我们测试这一假设，通过检查变异不变的讲话。以往的研究表明，典型的扬声器共振峰的变化（集中）在元音生产的初始阶段，从元音开始到元音中点观察减少。居中假设反映反馈为基础的自我产生的变异性校正，因此可以提供一个行为分析的反馈控制在不受干扰的语音以同样的方式作为补偿反应反馈扰动。方法为了全面比较CA患者和对照组的中心化，我们在两种情况下（孤立词和连接语音）检查两个元音（/i/和//）的中心化。作为对照，我们研究了有噪声和无噪声掩蔽听觉反馈的语音。结果与CA的个人没有显示出增加的中心相比，年龄匹配的控制，无论元音，上下文，或掩蔽。与以前的结果在神经生物学典型的扬声器，集中不受掩蔽噪声的存在下，在任何一组。结论：在有和没有掩蔽噪声的情况下，中心定位的幅度相似，这对中心定位是否由听觉反馈驱动提出了疑问。然而，如果集中至少部分是由听觉/体感反馈驱动，这些结果表明，较大的补偿反应，改变听觉反馈观察到的个人与CA可能不反映典型的运动控制过程中正常的，不变的语音生产。
Purpose Individuals with cerebellar ataxia (CA) caused by cerebellar degeneration exhibit larger reactive compensatory responses to unexpected auditory feedback perturbations than neurobiologically typical speakers, suggesting they may rely more on feedback control during speech. We test this hypothesis by examining variability in unaltered speech. Previous studies of typical speakers have demonstrated a reduction in formant variability (centering) observed during the initial phase of vowel production from vowel onset to vowel midpoint. Centering is hypothesized to reflect feedback-based corrections for self-produced variability and thus may provide a behavioral assay of feedback control in unperturbed speech in the same manner as the compensatory response does for feedback perturbations. Method To comprehensively compare centering in individuals with CA and controls, we examine centering in two vowels (/i/ and /ɛ/) under two contexts (isolated words and connected speech). As a control, we examine speech produced both with and without noise to mask auditory feedback. Results Individuals with CA do not show increased centering compared to age-matched controls, regardless of vowel, context, or masking. Contrary to previous results in neurobiologically typical speakers, centering was not affected by the presence of masking noise in either group. Conclusions The similar magnitude of centering seen with and without masking noise questions whether centering is driven by auditory feedback. However, if centering is at least partially driven by auditory/somatosensory feedback, these results indicate that the larger compensatory response to altered auditory feedback observed in individuals with CA may not reflect typical motor control processes during normal, unaltered speech production.