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Working memory processes in children with and without persistent speech sound disorders
Approximately 11-13% of children ages 5-7 years are diagnosed with a speech sound disorder (Shriberg, Tomblin, & McSweeney, 1999). Speech sound disorders (SSD) are a significant delay in the acquisition of articulate speech sounds (Lewis, Freebairn, Hansen, Shriberg, Stein, Taylor, & Iyengar, 2006) and often involve impairment in the phonological portion of a child's language system. There is a subgroup of children with SSD who have speech sound errors that persist past the point of typical development (i.e., 8-years-old). It is plausible that children who have persistent errors have deficits in underlying skills necessary for phonological production. The underlying skills necessary for phonological awareness and speech sound production are numerous and include among others: language, letter knowledge, phonological representations, and phonological working memory. Working memory (WM) is a cognitive process that facilitates the immediate storage and retrieval of phonological and visual information from long-term memory and may partially account for the phonological deficits seen in children with persistent SSD. ^ There are also lexical factors such as neighborhood density (ND) that may contribute to the speed of retrieval and storage of phonological information in working memory. ND is a metric used to quantify the number of similar words that reside within the lexicon. Children with SSD have been reported to recall both words and nonwords in high density neighborhoods better than words in low density neighborhoods. ^ This study aimed to examine the working memory differences in children with persistent speech sound disorders compared to typically developing children. In addition, the role of neighborhood density as well as the influence of speech production on working memory task performance was examined. The results of this study support the hypothesis that children with persistent speech sound disorders have a deficit specific to the phonological loop of working memory. In addition, phonologically similar features seen in neighborhood density contributed significantly to how children with P-SSD perform on working memory and phonological awareness tasks. However, these results do not exist in a vacuum; multiple linguistic and cognitive factors contribute to these children's performance on working memory tasks. Future research in this population of children should take into consideration the working memory deficits as well as nonverbal intelligence, expressive vocabulary, and word reading.^
Health Sciences, Speech Pathology|Psychology, Cognitive
Schussler, Kelly Farquharson, "Working memory processes in children with and without persistent speech sound disorders" (2012). ETD collection for University of Nebraska - Lincoln. AAI3522086.