Dimensional Thinking in Language Impaired Children

This study investigated the dimensional knowledge evidenced by language impaired (LI) preschoolers. Ten LI and 10 language normal (LN) children, aged 3:6 to 5:9, were asked to solve verbal and nonverbal problems requiring color and size judgments. There were no group differences on the verbal task, but the LI children performed less well than the LN children on the nonverbal task. Much of this difference stemmed from their difficulty with size items. The ordinal nature of the size dimension implies greater cognitive processing demands than are inherent in nominal dimensions such as color. Given the known processing limitations of language impaired children, this complexity apparently can lead to erroneous judgment even when requisite knowledge is present. It may also contribute to delays in the initial construction of dimensional knowledge.