Comprehension of reversible sentences in specifically language-impaired children

This study investigated comprehension of reversible sentences in specifically language-impaired (SLI) children. Two experiments, using different paradigms, were undertaken. In Experiment 1, 14 SLI children (aged 4:10-7:10) were compared with children matched on chronological age and language age (LA). Subjects acted out 36 semantically reversible sentences that varied in thematic content (transitives, locatives, and datives) and in the order of thematic roles (canonical and noncanonical). The SLI children performed at a significantly lower level than both control groups. In Experiment 2, the same sentences were presented using a picture-pointing task. A single word vocabulary test preceded the test sentences to assess semantic knowledge of the predicates. Sixteen SLI children were compared with language age controls. No significant differences were found between the performance of the two groups on the vocabulary test, and in general, the results of Experiment 2 supported those of Experiment 1. Analysis of individual children's error patterns identified qualitative differences between the SLI children and the LA controls. The majority of SLI children had a very high proportion of word order errors. The proportion of word order errors of the SLI children, unlike those of the LA controls, was unrelated to language age. These findings are considered in relation to the processes involved in sentence comprehension.