Verbal short-term memory in Down's syndrome: an articulatory loop deficit?

Area of Science:

• Cognitive Psychology
• Neurodevelopmental Disorders
• Genetics

Background:

• Verbal short-term memory is typically impaired in individuals with Down's syndrome (DS).
• Working memory models propose that articulatory loop sub-components may underlie phonological representation deficits in DS.
• This study investigates the specific role of the articulatory loop in verbal short-term memory deficits in DS.

Purpose of the Study:

• To test the hypothesis that impaired articulatory loop function contributes to reduced verbal short-term memory in Down's syndrome.
• To examine subvocal rehearsal and phonological store functioning in adolescents with DS compared to mental age-matched controls.

Main Methods:

• Two experiments were conducted with adolescents with DS and typically developing children matched for mental age.
• Experiment 1 assessed reliance on subvocal rehearsal and word frequency effects on word span.
• Experiment 2 investigated the phonological store component of the articulatory loop.

Main Results:

• A reduced verbal span in individuals with DS was confirmed.
• Neither DS individuals nor controls showed spontaneous subvocal rehearsal.
• Data provided limited evidence for defective phonological store functioning in DS.

Conclusions:

• Dysfunction of the articulatory loop does not significantly explain reduced verbal span in DS.
• Alternative explanations, such as central executive system impairment, should be considered for verbal short-term memory deficits in DS.