Working memory development in children with mild to borderline intellectual disabilities.
Verbal short-term memory tops out by age 10 in students with mild-borderline ID, so plan supports that bypass spoken memory loads.
01Research in Context
What this study did
Researchers tested 8- to young learners with mild or borderline intellectual disability.
They gave each child three kinds of memory tests: working memory, visuospatial short-term memory, and verbal short-term memory.
The team wanted to see how these skills grow across the school years.
What they found
Working memory and visuospatial memory kept improving until about age 15.
Verbal short-term memory stopped growing around age 10 and stayed flat.
This means older students still struggle to hold spoken words in mind.
How this fits with other research
O'Hearn et al. (2011) found the same kids have smaller phonological storage. The new study shows this gap never closes after age 10.
van Wingerden et al. (2017) showed reading stays at early levels for these students. The flat verbal memory line helps explain why decoding and listening skills stall.
Together, the three papers build a clear picture: limited verbal storage starts early and locks in, shaping both memory and reading growth.
Why it matters
You can stop expecting verbal rehearsal gains after fifth grade. Shift your supports: use visual aids, shorten spoken instructions, and preload key vocabulary on cards or tablets. This matches the child’s actual memory ceiling, not their age.
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02At a glance
03Original abstract
BACKGROUND: The purpose of the current cross-sectional study was to examine the developmental progression in working memory (WM) between the ages of 9 and 16 years in a large sample of children with mild to borderline intellectual disabilities (MBID). Baddeley's influential WM model was used as a theoretical framework. Furthermore, the relations between WM on the one hand, and scholastic skills (arithmetic and reading) on the other were examined. METHOD: One hundred and ninety-seven children with MBID between 9 and 16 years old participated in this study. All children completed several tests measuring short-term memory, WM, inhibition, arithmetic and single word reading. RESULTS: WM, visuospatial short-term memory and inhibition continued to develop until around age 15 years. However verbal short-term memory showed no further developmental increases after the age of 10 years. Verbal short-term memory was associated with single word reading, whereas inhibition was associated with arithmetic. DISCUSSION: The finding that verbal short-term memory ceases to develop beyond the age of 10 years in children with MBID contrasts with results of studies involving typically developing children, where verbal short-term memory develops until around age 15 years. This relative early developmental plateau might explain why verbal short-term memory is consistently considered weak in children with MBID.
Journal of intellectual disability research : JIDR, 2014 · doi:10.1111/jir.12061