Receptive vocabulary and semantic knowledge in children with SLI and children with Down syndrome

Abstract

Receptive vocabulary and associated semantic knowledge were compared within and between groups of children with specific language impairment (SLI), children with Down syndrome (DS), and typically developing children. To overcome the potential confounding effects of speech or language difficulties on verbal tests of semantic knowledge, a novel task was devised based on picture-based semantic association tests used to assess adult patients with semantic dementia. Receptive vocabulary, measured by word-picture matching, of children with SLI was weak relative to chronological age and to nonverbal mental age but their semantic knowledge, probed across the same lexical items, did not differ significantly from that of vocabulary-matched typically developing children. By contrast, although receptive vocabulary of children with DS was a relative strength compared to nonverbal cognitive abilities (p < .0001), DS was associated with a significant deficit in semantic knowledge (p < .0001) indicative of dissociation between word-picture matching vocabulary and depth of semantic knowledge. Overall, these data challenge the integrity of semantic-conceptual development in DS and imply that contemporary theories of semantic cognition should also seek to incorporate evidence from atypical conceptual development.

Keywords:

• Semantic cognition
• Specific language impairment
• Down syndrome
• Semantic
• Vocabulary

The authors thank the children who participated, and the teachers and schools that cooperated with the research.

Notes

1 Stroller in the United States.

Additional information

Funding

This work was supported by the Wellcome Trust (project grant number 076520). Laura Bence, Alison Fisher, Stephanie Guillaume, Elizabeth Main, Emily Mason-Apps, and Catherine White contributed to assessments or data coding and entry. Some data used in the study were gathered for MSc dissertations completed by Heather Brown and Anna Kapikian.