Danahy Kerry, Windsor Jennifer, Kohnert Kathryn
Department of Speech-Language-Hearing Sciences, University of Minnesota, Minneapolis, MN 55455, USA.
Int J Lang Commun Disord. 2007 May-Jun;42(3):349-65. doi: 10.1080/13682820600940083.
In recent research, verbal working memory has been proposed as a primary area of deficit for children with language impairment (LI), and therefore a source of more sensitive assessment measures. In addition, research on non-linguistic tasks has suggested that children with LI may have deficits that extend beyond the linguistic domain. These dual lines of research can be connected to the drive for non-biased assessment tasks for children with diverse language learning experiences (such as bilingual children), because linguistic tasks may be intrinsically biased against such children.
To investigate the usefulness of a working-memory task with a minimal linguistic load as a potential screening tool for children with primary LI.
METHODS & PROCEDURES: Three groups of children aged 7;10-13;11 participated in the study: monolingual English-speaking children with LI, typical monolingual English-speaking children, and typical Spanish-English bilingual children with several years of English experience. Performance of the three groups on the Counting Span task was explored through group comparisons and likelihood ratios.
OUTCOMES & RESULTS: Children with LI had significantly lower Counting Span Set score accuracy than either typical group, with the monolingual and bilingual groups showing equivalent task performance. However, results from likelihood ratios showed that Counting Span accuracy did not have compelling diagnostic power when the entire age group was considered. Children with less than 67% accuracy were only three times more likely to be from the LI group than from either of the two typical groups. In addition to language status (typical or LI), chronological age was a key contributor to Counting Span performance in this age group. Likelihood ratios for children aged 10;0 and above showed that children with less than 67% accuracy were nine times more likely to come from the LI group than the typical groups.
This intermediate diagnostic ability suggests that performance on the Counting Span alone is insufficient to identify LI among linguistically diverse learners. However, Counting Span may be a very useful component of a larger LI assessment battery, particularly for children over the age of 10;0.
在最近的研究中，言语工作记忆被认为是语言障碍（LI）儿童的一个主要缺陷领域，因此也是更敏感评估指标的一个来源。此外，对非语言任务的研究表明，LI儿童的缺陷可能超出语言领域。这两条研究路线可以与为具有不同语言学习经历的儿童（如双语儿童）开发无偏差评估任务的需求联系起来，因为语言任务可能在本质上对这类儿童存在偏差。
研究语言负荷最小的工作记忆任务作为原发性LI儿童潜在筛查工具的效用。
三组年龄在7岁10个月至13岁11个月的儿童参与了该研究：患有LI的单语英语儿童、典型的单语英语儿童以及有多年英语学习经验的典型西班牙语 - 英语双语儿童。通过组间比较和似然比来探究三组在数字广度任务上的表现。
患有LI的儿童在数字广度集合分数准确性方面显著低于任何一组典型儿童，单语组和双语组表现相当。然而，似然比结果表明，当考虑整个年龄组时，数字广度准确性并没有令人信服的诊断能力。准确性低于67%的儿童来自LI组的可能性仅比两个典型组中的任何一组高三倍。除了语言状态（典型或LI）外，实际年龄也是该年龄组数字广度表现的一个关键因素。10岁及以上儿童似然比表明，准确性低于67%的儿童来自LI组的可能性比典型组高九倍。
这种中等的诊断能力表明，仅依靠数字广度表现不足以在语言背景多样的学习者中识别出LI。然而，数字广度可能是更全面的LI评估组合中非常有用的一个组成部分，特别是对于10岁及以上的儿童。
