Relations among verbal and nonverbal cognitive skills in normal language and specifically language-impaired children.

This study tested the hypothesis that specifically language-impaired (SLI) children have a qualitatively different cognitive system from that of normal language (NL) children. Twenty NL and 20 SLI children between the ages of 4:2 (years:months) and 5:11 were presented with experimental language-learning measures, experimental nonverbal measures, and verbal and nonverbal norm-referenced tests. A confirmatory analysis of the covariance matrix structures of the two subject groups indicated that relations among cognitive skills differed between NL and SLI children. In addition, a planned comparison indicated that the relation between nonverbal rule-induction and novel bound-morpheme learning differed significantly between groups. The findings indicate that a "qualitative-differences" model of specific language impairment better accounts for the co-occurrence of poor verbal and poor nonverbal cognitive skills in SLI children than a "low-normal" model.