San Diego State University, 5500 Campanile Drive, San Diego, CA, 92182, United States of America.
University of Southern California, GFS 301, 3601 Watt Way, Los Angeles, CA, 90089, United States of America.
J Commun Disord. 2023 Jan-Feb;101:106297. doi: 10.1016/j.jcomdis.2022.106297. Epub 2022 Dec 31.
One way to identify Developmental Language Disorder (DLD) is to establish clinical markers in a language to serve as reliable indicators of the disorder. This study embarks on the search for clinical markers for Vietnamese using longitudinal data from children with and without DLD.
We matched ten children previously classified with DLD to ten with typical development (TD) by age and gender. Participants completed a story generation task at three time points: kindergarten, first, and second grade. Overall grammatical development was measured using mean length of utterance, MLU, and proportion of grammatical utterances, PGU. We examined a language-specific feature, classifiers, in terms of accuracy (omission errors), diversity (number of different classifiers), and productivity, or the use of classifiers in constructions of two-to-three elements (classifier+noun, numeral+classifier+noun). Longitudinal change and group differences were examined using linear mixed modeling, supplemented by linguistic analysis.
Both groups increased in MLU and PGU over time. The DLD group performed lower in kindergarten and continued to show lower performance over time on these measures. Classifier omission errors decreased over time with no group differences. Classifier diversity increased across groups, with lower performance by the DLD group in kindergarten and over time. For classifier productivity, TD children used classifiers in multiple constructions in kindergarten and maintained the same level over time. In contrast, children with DLD had minimal use of three-element constructions in kindergarten but increased in productivity over time.
Children with DLD produce shorter utterances with relatively more grammatical errors compared to their TD peers in the early school years. Though no longer committing classifier omission errors, children with DLD showed more restricted use of classifiers in terms of the number of different classifiers and constructions produced. Findings inform the search for Vietnamese clinical markers of DLD.
鉴定发育性语言障碍（DLD）的一种方法是在语言中建立临床标记，作为该障碍的可靠指标。本研究使用有和无 DLD 的儿童的纵向数据，开始寻找越南语的临床标记。
我们根据年龄和性别，将之前被诊断为 DLD 的 10 名儿童与具有典型发展（TD）的 10 名儿童相匹配。参与者在三个时间点完成了一个故事生成任务：幼儿园、一年级和二年级。使用平均话语长度（MLU）和语法话语比例（PGU）来衡量整体语法发展。我们从准确性（省略错误）、多样性（不同分类器的数量）和生产能力（在二到三个元素的结构中使用分类器的能力，即分类器+名词、数字+分类器+名词）的角度检查了语言特异性特征——分类器。使用线性混合建模检查纵向变化和组间差异，并辅以语言分析。
两组的 MLU 和 PGU 随时间增加。DLD 组在幼儿园时表现较低，在这些测量中随时间推移表现持续较低。分类器省略错误随时间减少，两组之间没有差异。分类器多样性随时间增加，DLD 组在幼儿园时表现较低，随时间推移表现较低。对于分类器生产能力，TD 儿童在幼儿园时在多个结构中使用了分类器，并且随时间推移保持了相同的水平。相比之下，DLD 儿童在幼儿园时使用三元素结构的能力非常有限，但随时间推移，生产能力有所提高。
与同龄的 TD 儿童相比，DLD 儿童在早期学年期间产生的话语较短，且相对更多的语法错误。尽管不再犯分类器省略错误，但 DLD 儿童在使用不同分类器和生成结构的数量方面表现出更受限的分类器使用。研究结果为寻找越南语 DLD 的临床标记提供了信息。
