Word-length effect in verbal short-term memory in individuals with Down's syndrome.
For kids with Down syndrome, short verbal memory is limited by how fast they can find words, not how fast they can speak.
01Research in Context
What this study did
The team asked kids to repeat lists of words. Some lists had short words like 'cat.' Others had long words like 'elephant.'
They tested the children with Down syndrome. They also tested the kids without disabilities who had the same mental age.
What they found
Both groups remembered fewer long words than short words. Kids with Down syndrome remembered fewer words overall.
Talking speed did not predict who forgot more. The real problem was how fast they could find the word in their head.
How this fits with other research
Neitzel et al. (2021) later showed that better verbal short-term memory helps kids with Down syndrome pass false-belief tasks. This extends the 2002 finding: memory support may boost social skills too.
Leclercq et al. (2014) saw a similar lexical effect in children with specific language impairment. Low-frequency words hurt comprehension just like long words hurt recall. Both studies point to weak word access, not weak grammar.
Durbin et al. (2019) found that kids with Down syndrome do not gain from sleep-dependent learning, while kids with Williams syndrome do. Together these papers map different memory bottlenecks across syndromes.
Why it matters
When you teach a client with Down syndrome, keep vocabulary short and familiar. Use pictures or signs to offload the verbal channel. Check that they can quickly name the items before you ask them to remember a list. These small tweaks target the real problem: lexical access speed, not speech rate.
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02At a glance
03Original abstract
BACKGROUND: Many studies have indicated that individuals with Down's syndrome (DS) show a specific deficit in short-term memory for verbal information. The aim of the present study was to investigate the influence of the length of words on verbal short-term memory in individuals with DS. METHODS: Twenty-eight children with DS and 10 control participants matched for memory span were tested on verbal serial recall and speech rate, which are thought to involve rehearsal and output speed. RESULTS: Although a significant word-length effect was observed in both groups for the recall of a larger number of items with a shorter spoken duration than for those with a longer spoken duration, the number of correct recalls in the group with DS was reduced compared to the control subjects. The results demonstrating poor short-term memory in children with DS were irrelevant to speech rate. In addition, the proportion of repetition-gained errors in serial recall was higher in children with DS than in control subjects. CONCLUSIONS: The present findings suggest that poor access to long-term lexical knowledge, rather than overt articulation speed, constrains verbal short-term memory functions in individuals with DS.
Journal of intellectual disability research : JIDR, 2002 · doi:10.1046/j.1365-2788.2002.00438.x