Speech categorization consistency is associated with language and reading abilities in school-age children: Implications for language and reading disorders.

Speech perception is fundamental to language and reading abilities. While these skills are correlated, most studies examining the role of speech perception on outcomes do not test both concurrently. Moreover, traditional forced-choice tasks have limitations in accurately indexing these relationships. This study used a visual analog scaling task-a continuous measure of speech categorization-to examine speech categorization alongside conventional language and reading assessments in a large sample of children (n = 237), including those with language and/or reading disabilities. Children with poorer language/reading exhibited lower trial-by-trial categorization consistency, but no differences in the gradiency of the mean function. Group analyses further linked differences in categorization consistency to language/reading disabilities, with reading ability being linked particularly to the processing of vowels. Critically, categorization consistency was uniquely linked to language/reading ability, even when controlling for the mediating effect of phonological processing. These findings suggest that the consistency of perceptual processes, rather than the quality of the representations, is the critical property of speech perception that is associated with broader language and reading function.