Working memory functions in children with different degrees of intellectual disability.
Phonological working memory in kids with ID is structurally impaired, so lighten verbal load and lean on visual supports.
01Research in Context
What this study did
Xenitidis et al. (2010) looked at working memory in children with intellectual disability. They compared kids with mild, moderate, and severe ID to see which memory parts broke down.
The team tested the phonological loop, visuospatial sketchpad, and central executive. They wanted to know if poor scores were a delay or a permanent difference.
What they found
Children with ID had weaker working memory as disability level rose. The phonological loop showed the biggest hit and looked like a structural flaw, not just slow growth.
Other memory systems acted more like normal development running late.
How this fits with other research
Stancliffe et al. (2007) saw the same phonological weakness in mild ID and called it a delay. K et al. now say the loop is built differently, updating that view.
Cudré-Mauroux (2010) tested the episodic buffer in kids with ID and found mental-age level scores. Together the papers show one memory lane is broken while another simply lags.
Firth et al. (2001) found a large phonological deficit in adults with Down syndrome but intact everyday skills. K et al. extend this pattern to children across all ID levels.
Why it matters
You now know the phonological loop is a hard weakness, not a late bloomer. When you teach reading or following multi-step instructions, cut phonological load first. Use visual cues, shorter spoken chains, and repeated practice. Target mental-age goals for other memory tasks, but do not expect the loop to catch up.
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02At a glance
03Original abstract
BACKGROUND: In recent years, there has been increased research interest in the functioning of working memory in people with intellectual disabilities. Although studies have repeatedly found these individuals to have weak working memory skills, few investigations have distinguished between different degrees of intellectual disability. This study aims to help close this research gap and, in so doing, to examine whether the deficits observed reflect a developmental lag or a qualitative deviation from normal development. METHOD: In a 5-group design, the working memory performance of a group of 15-year-olds with mild intellectual disability (IQ 50-69) was compared with that of two groups of children (aged 10 and 15 years) with borderline intellectual disability (IQ 70-84) and with that of two groups of children with average intellectual abilities (IQ 90-115) matched for mental and chronological age (aged 7 and 15 years). All children were administered a comprehensive battery of tests assessing the central executive, the visual-spatial sketchpad, and the phonological loop. RESULTS: The results showed deficits in all three components of working memory, and revealed that these deficits increased with the degree of intellectual disability. The findings indicate that, relative to their mental age peers, children with learning difficulties show structural abnormalities in the phonological store of the phonological loop, but developmental lags in the other two subsystems. CONCLUSIONS: Similar patterns of results emerged for both subgroups of children with intellectual disability, indicating that problems with phonological information processing seem to be one of the causes of cognitive impairment in individuals with intellectual disability.
Journal of intellectual disability research : JIDR, 2010 · doi:10.1111/j.1365-2788.2010.01265.x