Rice M L, Wexler K
University of Kansas, Lawrence, USA.
J Speech Hear Res. 1996 Dec;39(6):1239-57. doi: 10.1044/jshr.3906.1239.
A critical clinical issue is the identification of a clinical marker, a linguistic form or principle that can be shown to be characteristic of children with Specific Language Impairment (SLI). In this paper we evaluate, as candidate clinical markers, a set of morphemes that mark Tense. In English, this includes -s third person singular, -ed regular past, BE, and DO. According to the Extended Optional Infinitive Account (EOI) of Rice, Wexler, and Cleave (1995), this set of morphemes is likely to appear optionally in the grammars of children with SLI at a rate lower than the optionality evident in younger controls. Three groups of preschool children participated: 37 children with SLI, and two control groups, one of 40 MLU-equivalent children and another of 45 age-equivalent children. Three kinds of evidence support the conclusion that a set of morphemes that marks Tense can be considered a clinical marker: (a) low levels of accuracy for the target morphemes for the SLI group relative to either of the two control groups; (b) affectedness for the set of morphemes defined by the linguistic function of Tense, but not for morphemes unrelated to Tense; and (c) a bimodal distribution for Tense-marking morphemes relative to age peers, in which the typical children are at essentially adult levels of the grammar, whereas children in the SLI group were at low (i.e., non-adultlike) levels of performance. The clinical symptoms are evident in omissions of surface forms. Errors of subject-verb agreement and syntactic misuses are rare, showing that, as predicted, children in an EOI stage who are likely to mark Tense optionally at the same time know a great deal about the grammatical properties of finiteness and agreement in the adult grammar. The findings are discussed in terms of alternative accounts of the grammatical limitations of children with SLI and implications for clinical identification.
一个关键的临床问题是识别一种临床标志物，即一种语言形式或原则，它能够被证明是特定语言障碍（SLI）儿童的特征。在本文中，我们评估了一组表示时态的语素作为候选临床标志物。在英语中，这包括第三人称单数形式 -s、规则过去式 -ed、BE动词和DO。根据赖斯、韦克斯勒和克利夫（1995）的扩展可选不定式理论（EOI），这组语素在SLI儿童的语法中出现的频率可能低于年龄较小的对照组，且具有可选性。三组学龄前儿童参与了研究：37名患有SLI的儿童，以及两个对照组，一组是40名语言发育迟缓程度相当的儿童，另一组是45名年龄相当的儿童。有三种证据支持这样的结论，即一组表示时态的语素可以被视为临床标志物：（a）相对于两个对照组中的任何一组，SLI组目标语素的准确率较低；（b）由时态的语言功能定义的语素集合受到影响，但与时态无关的语素不受影响；（c）相对于同龄人，时态标记语素呈现双峰分布，其中典型儿童的语法水平基本达到成人水平，而SLI组儿童的表现水平较低（即非成人水平）。临床症状在表层形式的省略中很明显。主谓一致错误和句法误用很少见，这表明，正如预测的那样，处于EOI阶段的儿童虽然可能会同时以可选方式标记时态，但他们对成人语法中的限定性和一致性的语法属性也有很多了解。本文从对SLI儿童语法限制的不同解释以及对临床识别的影响方面对研究结果进行了讨论。
