and Prereading: Update on a Longitudinal Study

This study examined the effects of overt phonologic impairment (disordered speech) on phonological awareness, verbal working memory, and letter knowledge. Forty-five children—29 with moderate to severe productive phonologic impairment at the inception of the project and 16 without impairment—were followed from mean age 3-6 to age 6-0. Fifteen participants with impairment were matched on gender and mental age to 15 without impairment for certain aspects of the analysis. The children with phonologic impairment performed significantly worse than their controls on tasks of verbal working memory, phoneme segmentation, and letter identification. In addition, a path analysis revealed working memory to be a potentially important mediating variable. The investigators also measured productive syntax, which, although associated with productive phonology and working memory, was not associated with letter identification. Research findings regarding lit-eracy acquisition in children with contemporaneous and/or historical phonologic impairment are perplexing. Phonologic impairment re-fers to a disturbance in the speech-sound system that results in systematic speech errors, rendering a speaker difficult to understand. Although the intuitive assumption (supported by clinical observations) may be that chil-dren with phonologic impairment are at significant risk for literacy prob-lems, strong empirical support for this is lacking to date (Hodson, 1994; Hod-son, Nonomura, & Zappia, 1989). A collection of retrospective and prospec-tive studies has provided support, however, for an increased risk for litera-cy problems in children with speech-language impairment as a group (e.g.