UBC Theses and Dissertations
Central executive functions in children with specific language impairment Reggin, Lorraine Dale
The present study examined the phonological and visual components of working memory, both singly and within a dual-task presentation, in order to investigate the central executive functioning of children with Specific Language Impairment (SLI). Thirteen children with SLI (age 6;1 - 9;8) were matched by age to 11 children who showed normal language development (NL). Both groups completed a Nonword Repetition task (Dollaghan & Campbell, 1998) and a visual-spatial task requiring Memory for Locations. In the latter, children saw a 4 x 4 grid in which a given number of identical monsters were randomly placed. Following a 500 ms delay, children had to recall the positions of the monsters on a blank grid by pointing. Each child's span level was ascertained on each task and then the tasks were presented "simultaneously" at the child's own level. Children saw a 4 x 4 grid with a "span-level" number of monsters. The screen went blank for 5 seconds and the child repeated nonwords with a "span-level" number of syllables. Finally, an empty grid appeared and the child had to recall the monsters' positions. In a control condition, children recalled locations after a 5 sec delay with no word repetition. The results of the study indicated that children with SLI had significantly lower nonword repetition "spans" than children with NL, but showed only a nonsignificant difference in "spans" for visual locations. On the dual task, there was a significant decrement in visual task performance due to delay and a further significant decrement due to interference of auditory task, but no group differences in degree or pattern of decrement. The findings imply that the combined storage load from different modalities does call on the central executive for resource management, but that this may not be a source of difference between children with SLI and children with NL.
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