Rapid naming and phonemic awareness in children with reading disabilities and/or specific language impairment: differentiating processes?

De Groot, B. J. A., Van den Bos, K. P., Van der Meulen, B.F., Minnaert, A. E. M. G. (2015). Rapid naming and phonemic awareness in children with reading disabilities and/or specific language impairment: differentiating processes? Journal of Speech, Language, and Hearing Research, 58. 1538-1548.

Specific language impairment (SLI) and reading disability (RD) have higher rates of comorbidity than expected, and it remains unclear how the two disorders are related to one another. The current study examined whether decoding and recognition processes during reading can be differentiated in children with SLI with or without a comorbid RD. Phonemic awareness (PA), the ability to identify and manipulate speech sounds, is often considered to be a core deficit of RD, although studies have also observed PA deficits in children with SLI. Rapid automatized naming (RAN) involves naming arrays of objects, colours, letters, or numbers, and has been shown to be impaired in RD.

In the present study, groups of children between 8 and 13 years old with SLI, RD, and comorbid SLI and RD completed RAN and PA tasks to examine whether performance on both tasks would differ between groups. The RAN tasks included a letter array and a number array, and the PA tasks consisted of an elision task (i.e. say “string” without the “r”) and a substitution task (switch the first sounds in the words “red fish”). Performance was analyzed using a principal components analysis, which revealed two components explaining 85% of the variance: a RAN factor and a PA factor. The analyses revealed that the SLI-only group had low PA scores, the RD-only group had low scores on both RAN and PA, and the comorbid SLI and RD group had the most severely impaired performance on all the tasks. A similar pattern of results was demonstrated with a multivariate analysis of variance.

These findings are consistent with past research demonstrating RAN and PA impairments in children with RD.  Although some literature suggests that PA impairments may not be severe in children with SLI older than 9 years, the severe PA impairment observed in the present study’s SLI group may be associated with the large short-term memory load in the PA substitution task. The authors suggest that their data best fits a model of RD and SLI in which the two disorders are similar but distinct phonologically-linked disorders. The authors emphasize the importance of distinguishing between RD-only, SLI-only, and comorbid groups in research and in clinical practice, given that additive impairment effects were observed when SLI and RD occurred comorbidly.

Blogger: Alex Cross; Alex is a student in the combined speech language pathology/Ph.D. program supervised by Drs. Lisa Archibald and Marc Joanisse