On the association between serial naming speed for letters and digits and word-reading skill: towards a developmental account

The current study examined several alternative explanations of the association between serial naming speed within fourth-grade children by determining the extent to which the association between word reading and naming speed for letters and numbers is mediated by global processing speed, alphanumeric symbol processing efficiency and phonological processing ability. Children were given multiple measures of key constructs, i.e. word-level reading, serial naming of both alphanumeric and non-alphanumeric items, phonological processing ability, articulation rate and global processing speed. The robust association between alphanumeric naming speed and reading within fourth-grade children was largely mediated by phonological processing ability. Markedly different patterns of results were observed for naming speed for letters and digits and naming speed for colours and pictures in children of this age. Relative to the latter, alphanumeric naming speed better assesses an underlying phonological processing ability that is common to word-reading ability. We argue that item identification processes contribute little to individual differences in alphanumeric naming speed within relatively proficient readers and that the extent to which alphanumeric naming speed primarily reflects phonological processing is likely to vary with the level of overlearning of letters and numbers and their names.