Stimulus length on speech stability in ALS (Teplansky et al., 2024)

Purpose: This study aimed to investigate the effect of stimulus signal length on tongue and lip motion pattern stability in speakers diagnosed with amyotrophic lateral sclerosis (ALS) compared to healthy controls.Method: Electromagnetic articulography was used to derive articulatory motion patterns from individuals with mild (n = 27) and severe (n = 16) ALS and healthy controls (n = 25). The spatiotemporal index (STI) was used as a measure of articulatory stability. Two experiments were conducted to evaluate signal length effects on the STI: (a) the effect of the number of syllables on STI values and (b) increasing lengths of subcomponents of a single phrase. Two-way mixed analyses of variance were conducted to assess the effects of syllable length and group on the STI for the tongue tip (TT), tongue back (TB), and lower lip (LL).Results: Experiment 1 showed a significant main effect of syllable length (TT, p < .001; TB, p < .001; and LL, p < .001) and group (TT, p = .037; TB, p = .007; and LL, p = .017). TB and LL stability was generally higher with speech stimuli that included a greater number of syllables. Articulatory variability was significantly higher in speakers diagnosed with ALS compared to healthy controls. Experiment 2 showed a significant main effect of length (TT, p < .001; TB, p = .015; and LL, p < .001), providing additional support that STI values tend to be greater when calculated on longer speech signals.Conclusions: Articulatory stability is influenced by the length of speech signals and manifests similarly in both healthy speakers and persons with ALS. TT stability may be significantly impacted by phonemic content due to greater movement flexibility. Compared to healthy controls, there was an increase in articulatory variability in those with ALS, which likely reflects deviations in speech motor control.Supplemental Material S1. Main and interaction effects of length (2-, 3-, 5-, 8-syllables) and group (control, mild ALS, severe ALS) from two-way mixed ANOVA for all articulators. Statistics were performed on original data. Statistically significant effects are in bold.Supplemental Material S2. Bonferroni corrected pairwise comparisons to assess mean differences in STI with 95% confidence intervals. Statistics were performed on original data. Statistically significant differences are in bold.Supplemental Material S3. Main and interaction effects of segment length (25%, 50%, 75%, 100% of an 8-syllable phrase) and group (control, Mild ALS, Severe ALS) from two-way mixed ANOVA for all articulators. Statistics were performed on original STI values. Statistically significant effects are in bold.Supplemental Material S4. Bonferroni corrected pairwise comparisons to assess mean differences in STI values. Mean differences are provided for each articulator. Statistics were performed on original STI values. Statistically significant differences are in bold.Teplansky, K. J., Wisler, A., Goffman, L., & Wang, J. (2024). The impact of stimulus length in tongue and lip movement pattern stability in amyotrophic lateral sclerosis. Journal of Speech, Language, and Hearing Research, 67(10S), 4002–4014. https://doi.org/10.1044/2023_JSLHR-23-00079Publisher Note: This article is part of the Special Issue: Select Papers From the 8th International Conference on Speech Motor Control.

研究目的：本研究旨在探究刺激信号长度对患有肌萎缩侧索硬化症（ALS）的说话者与健康对照者舌部和唇部运动模式稳定性的影响。研究方法：采用电磁语图学技术从轻度（n = 27）和重度（n = 16）ALS患者以及健康对照者（n = 25）中提取发音运动模式。时空指数（STI）被用作发音稳定性的衡量指标。进行了两项实验以评估信号长度对STI的影响：（a）音节数量对STI值的影响；（b）单个短语子组件长度的增加。通过双向混合方差分析对音节长度和组别对舌尖（TT）、舌根（TB）和下唇（LL）的STI的影响进行了评估。研究结果：实验1显示音节长度（TT，p < .001；TB，p < .001；和LL，p < .001）和组别（TT，p = .037；TB，p = .007；和LL，p = .017）存在显著的主效应。TB和LL的稳定性在包含更多音节的语音刺激中普遍较高。与健康对照者相比，ALS患者的发音可变性显著增加。实验2显示长度（TT，p < .001；TB，p = .015；和LL，p < .001）存在显著的主效应，进一步支持了STI值在较长的语音信号上计算时往往较大的观点。研究结论：发音稳定性受语音信号长度的影响，并在健康说话者和ALS患者中表现出相似性。舌尖的稳定性可能因更大的运动灵活性而受到音素内容的显著影响。与健康对照者相比，ALS患者的发音可变性增加，这很可能反映了言语运动控制的偏差。补充材料S1：所有发音器官的长度（2-、3-、5-、8-音节）和组别（对照组、轻度ALS、重度ALS）的双向混合方差分析的主要和交互效应。统计是在原始数据上进行的。具有统计学意义的效应以粗体显示。补充材料S2：Bonferroni校正的双向比较以评估STI的均值差异和95%置信区间。统计是在原始数据上进行的。具有统计学意义的差异以粗体显示。补充材料S3：所有发音器官的片段长度（8音节短语的25%、50%、75%、100%）和组别（对照组、轻度ALS、重度ALS）的双向混合方差分析的主要和交互效应。统计是在原始STI值上进行的。具有统计学意义的效应以粗体显示。补充材料S4：Bonferroni校正的双向比较以评估STI值均值差异。为每个发音器官提供了均值差异。统计是在原始STI值上进行的。具有统计学意义的差异以粗体显示。Teplansky, K. J., Wisler, A., Goffman, L., & Wang, J. (2024). 肌萎缩侧索硬化症中刺激长度对舌部和唇部运动模式稳定性的影响。言语、语言和听力研究杂志，67(10S)，4002–4014. https://doi.org/10.1044/2023_JSLHR-23-00079出版者注：本文是特别专题“第八届国际言语运动控制会议精选论文”的一部分。