Chronological age, receptive vocabulary, and syntax comprehension in children and adolescents with mental retardation.

This study was designed to examine the association of CA with syntax and vocabulary comprehension in children and adolescents with mental retardation. It was conducted using the PPVT-R and the Test for Reception of Grammar. The cognitive level of participants was estimated by means of three nonverbal intelligence tests. Results indicated that scores on intelligence tests account for 55% and 29% of the variability of syntax and vocabulary scores, respectively. For the vocabulary, the introduction of CA into the regression equation produced a significant increment of the variance explained (17%). However, its contribution to the variance of the syntax test was not significant. This finding suggests that CA-related experience is linked to on the receptive vocabulary of children and adolescents with mental retardation.