Verbal short-term memory in individuals with congenital articulatory disorders: new empirical data and review of the literature.

Eisenhower et al. (2006) looked at verbal short-term memory in people born without speech plus intellectual disability. They compared this group to peers who could speak. Everyone did simple memory tasks with sounds and words.

The team checked for three normal memory tricks: phonological similarity, word length, and word frequency. These tricks show the brain is silently rehearsing speech. No tricks meant the articulatory loop was broken.

The non-speaking group showed none of the usual memory patterns. They did not mix up similar sounds, did not do worse on long words, and did not favor common words. Their silent rehearsal system was missing.

The authors say these kids never built the articulatory loop. Instead, they rely on pictures or meaning to hold information.

Hawley et al. (2004) saw a similar memory drop in Down syndrome, but blamed central executive problems, not the loop. The two studies seem to clash, yet they tested different parts of memory. A et al. ruled out rehearsal tricks, while S et al. ruled out storage size. Together they show the whole verbal system is fragile in developmental disability.

Roch et al. (2012) later showed kids with Down syndrome understand text better than spoken words when pictures support the text. This extends A et al.’s advice: skip sound-based rehearsal and give visual or semantic help.

Martínez-Castilla et al. (2024) added that teens with Down syndrome also struggle with tiny timing cues in speech. This widens the idea that auditory timing, not just articulation, is weak across ID groups.

If your client cannot speak, do not ask them to “say it in your head.” They probably can’t. Give them pictures, written key words, or meaning cues instead. Match memory aids to their visual strength, not their missing inner voice.