Semantic representation and naming in children with specific language impairment.

When 16 children with SLI (mean age = 6;2) and 16 normally developing age-mates named age-appropriate objects, the SLI cohort made more naming errors. For both cohorts, semantic misnaming and indeterminate responses were the predominant error types. The contribution of limited semantic representation to these naming errors was explored. Each participant drew and defined each item from his or her semantic and indeterminate error pools and each item from his or her correctly named pool. When compared, the drawings and definitions of items from the error pools were poorer, suggesting limited semantic knowledge. The profiles of information included in definitions of items from the correct pool and the error pools were highly similar, suggesting that representations associated with misnaming differed quanlitatively, but not qualitatively, from those associated with correct naming. Eleven members of the SLI cohort also participated in a forced-choice recognition task. Performance was significantly lower on erroneous targets than on correctly named targets. When performance was compared across all three post-naming tasks (drawing, defining, recognition), the participants evinced sparse semantic knowledge for roughly half of all semantic misnaming and roughly one third of all indeterminate responses. In additional cases, representational gaps were evident. This study demonstrates that the degree of knowledge represented in the child's semantic lexicon makes words more or less vulnerable to retrieval failure and that limited semantic knowledge contributes to the frequent naming errors of children with SLI.

Semantic representation and naming in young children.

Children's semantic representations and semantic naming errors were the focus of this study. In Experiment 1, 25 normally developing children (mean age = 5 years 4 months) named, drew, and defined 20 age-appropriate objects. The results suggested that functional and physical properties are core aspects of object representations in the semantic lexicon and that these representations are often organized and accessed according to a taxonomic hierarchy. Results of a new procedure, comparative picture naming/picture drawing, suggested that the degree of knowledge in the semantic lexicon makes words more or less vulnerable to retrieval failure. Most semantic naming errors were associated with limited semantic knowledge, manifested as either lexical gaps or fragile representations. Comparison of definitions for correctly named and semantically misnamed objects provided converging evidence for this conclusion. In Experiment 2, involving 16 normally developing children (mean age = 5 years 5 months), the comparative picture naming/picture drawing results were replicated with a stimulus set that allowed a priori matching of the visual complexity of items drawn from correct and semantic error pools. Discussion focuses on the dynamic nature of semantic representations and the relation between semantic representation and naming during a period of slow mapping. The value of comparative picture naming/picture drawing as a new method for exploring children's semantic representations is emphasized.