Abstract
Purpose: The aim of this study was to explore the role of working memory processes as a possible cognitive underpinning of persistent speech sound disorders (SSD).
Method: Forty school-aged children were enrolled; 20 children with persistent SSD (P-SSD) and 20 typically developing children. Children participated in three working memory tasks – one to target each of the components in Baddeley’s working memory model: phonological loop, visual spatial sketchpad and central executive.
Result: Children with P-SSD performed poorly only on the phonological loop tasks compared to their typically developing age-matched peers. However, mediation analyses revealed that the relation between working memory and a P-SSD was reliant upon nonverbal intelligence.
Conclusion: These results suggest that co-morbid low-average nonverbal intelligence are linked to poor working memory in children with P-SSD. Theoretical and clinical implications are discussed.
Acknowledgements
The authors thank the following funding sources for stimuli and task development as well as participant recruitment support: National Institutes of Health R03 Small Grant Award (R03 DC9667) (Hogan) National Institutes of Health R01 (R01 DC010784) (Gray, Alt, Hogan, Cowan, and Green) and Barkley Memorial Trust Dissertation Award (Farquharson). The authors thank the following team for the creation of the stop-signal central executive task: Shelley Gray, Mary Alt, Tiffany Hogan, Nelson Cowan and Trudy Kuo. The authors thank Jordan Green and Mary Alt for helpful suggestions on drafts of this manuscript.
Declaration of interest
The authors have no financial interest or benefit that has arisen from the direct applications of this research.
Supplementary material
Supplemental data for this article can be accessed at http://dx.doi.org/10.1080/17549507.2017.1293159