Evaluation of the role of phonological STM in the development of vocabulary in children: A longitudinal study

Abstract

This study explores the hypothesis that the short-term phonological storage component of working memory may play a role in the acquisition of vocabulary by young children. In a longitudinal design, the vocabulary skills of 104 children entering school between the ages of 4 and 5 were tested and retested 1 year later. On both occasions, phonological memory was investigated by requiring a child to repeat back nonwords varying in length and complexity, while nonverbal intelligence and reading were assessed using standard tests. The phonological memory score was highly correlated with vocabulary at both age 4 ( r = .525) and age 5 ( r = .572), in both cases accounting for a substantial and significant proportion of the variance when all other predictors are removed by stepwise regression. Phonological memory at age 4 also accounted for a significant amount of variance in vocabulary score at age 5, over and above that accounted for by the vocabulary score the previous year. Although these relationships are necessarily correlational in nature, the data are certainly consistent with the view that phonological memory is involved in the acquisition of new vocabulary in children. Possible mechanisms accounting for this relationship are discussed.