Lexical learning skills in young children with specific language impairment (SLI)

Twenty-eight children with specific language impairment (SLI) aged 4; 4-5; 10, and 28 children with normal language (NL) aged 2; 4-3; 7 were exposed to four novel verbs, and four novel nouns in eight naturalistic play sessions, over 4 weeks. Spontaneous utterances of the novel lexical items in each of the training sessions were recorded and formed the basis of the analyses. The results of the spontaneous production data (across all sessions) revealed that children with NL produced more novel verbs than children with SLI, with a trend for children with SLI to produce more novel nouns. Importantly, children with SLI learned novel verbs at a slower rate than children with NL. Results are discussed in relation to current theories of SLI with particular reference to the SLI critical mass hypothesis.