Abstract
Purpose: To gain a better understanding of the cognitive processes supporting verbal abilities, the underlying structure and interrelationships between common verbal measures were investigated.
Methods: An epidemiological sample (n = 374) of school-aged children completed standardized tests of language, intelligence, and short-term and working memory, as well as nonstandardized measures of grammaticality judgment, rapid naming, and sentence recall.
Results: Results of a principal component analysis revealed 4 factors corresponding to domain-general working memory, language processing, phonological short-term memory, and fluid reasoning. In corresponding analyses based on younger and older halves of the data, more variables loaded on the fluid reasoning factor for the younger group, and more task variance was explained by the language or phonological storage factors for the older group. The language processing factor correlated with all of the nonstandardized measures, whereas rapid naming was additionally correlated with working memory.
Discussion/conclusions: Separable cognitive processes influence performance on common verbal measures, which has implications for assessment and intervention of children with developmental language impairments.