Linda Swisher

MRI findings in boys with specific language impairment

Magnetic resonance imaging scans of specifically language-impaired (SLI) boys were examined to determine whether atypical cerebral findings could be documented in children whose primary deficits were in language skills. Clinical examination of the scans failed to reveal any visually obvious lesions or abnormalities. In contrast, measurement of the scans revealed atypical perisylvian asymmetries in most of these subjects. The distribution of perisylvian asymmetries in SLI subjects was significantly different from the distribution in controls (p less than .01). Measurement of other brain regions revealed that extraperisylvian areas were occasionally deviant in individual SLI subjects; but no one region was consistently deviant across the SLI group. Thus, only atypical perisylvian asymmetries were linked to the language disorder. These neuroanatomical findings suggest that a prenatal alteration of brain development underlies specific language impairment.

Nonlinguistic Deficits of Children with Language Disorders Complicate the Interpretation of Their Nonverbal IQ Scores.

This study supports the hypothesis that the nonlinguistic deficits of children with language impairment (LI) adversely affect their responses to specific item types represented on nonverbal IQ tests (Kaufman Assessment Battery for Children-Nonverbal Scale, Leiter International Performance Scale, and Matrix Analogies Test-Short Form). Twelve children with normal language (NL) and 12 with LI (8 to 10 years of age), matched for gender and age, served as subjects. A two-way mixed ANOVA revealed main effects (p<.05) for group and for test, and a Tukey HSD post-hoc analysis indicated significant between-group differences for each test. Robust effect sizes were found with item types judged a priori to assess deficit areas in children with LI. The extent to which certain item types correlated with IQ scores differed by subject group. The findings call into question the use of nonverbal IQ scores as measures of general intelligence or potential as well as their use to qualify children with LI for clinical services.

Bound-morpheme skills in the oral language of school-age, language-impaired children

Bound-morphine skills of school-age, language-impaired (LI) children were explored with three tasks designed to assess multiple dimensions of this component of language. Ten English-speaking, school-age LI children (Mean age: 10:3) and ten children with normal language (Mean age: 9:9) served as subjects. A two-way analysis of variance revealed significant group differences. Fisher a priori testing documented significant group differences for a measure of English bound-morpheme skill levels, a measure of ability to generalize English bound-morphemes to novel words, and a measure of ability to learn novel bound-morphemes attached to novel words. The findings indicate that core features of developmental language impairment in preschool children--poor ability to learn, to use, and to generalize bound-morphemes--are also present in school-age, LI children.

The Expressive Language Characteristics of Autistic Children Compared with Mentally Retarded or Specific Language-Impaired Children

For purposes of this chapter, the three developmental disorders of autism, mental retardation, and specific language impairment will be defined as follows:

Neurobehavioural analogies between syndromes of acquired and developmental language impairment: Hypotheses for research

Abstract From traditional accounts of acquired aphasia this paper generates hypotheses about a developmental language disorder called specific language impairment SLI). We first propose that there are two types of SLI and that they share behavioural characteristics with two types of aphasia. We suggest that adult-onset Brocas aphasia, the typical type of child-onset aphasia, and the phonological—syntactic type of SLI share a common set of non-fluent language behaviours; and that adult-onset and child-onset fluent aphasias and the semantic—pragmatic type of SLI share a common set of fluent language behaviours. Our approach is then to infer, by analogical reasoning, the neuroanatomical basis of the two types of SLI from what is known about the neuroanatomical basis of the two types of aphasia. Previous investigators who reasoned by analogy have explained SLI as a unitary phenomenon by positing bilateral hemispheric dysfunction. We posit instead that the bilateral hemisphere hypothesis is needed only to acc...