A number of previous studies have suggested that young people with Down's s
yndrome (DS) have a specific deficit of the phonological loop component of
the working memory. However, there have also been studies which have propos
ed a specific deficit of the central executive component of working memory
and suggested similarities of working memory functioning with patients with
Alzheimer's disease. Fifteen middle-aged people with DS were matched for t
heir individual scores of non-verbal intelligence to 15 individuals with mi
xed aetiology of intellectual disability. A versatile range of tasks was us
ed in order to evaluate the functioning of working memory components. In ad
dition, several everyday cognition skills were assessed. The subjects with
DS performed significantly more poorly in all tasks assessing the phonologi
cal loop. Performance in other working memory tasks and compound variables
representing different working memory components was equal in the groups. I
n addition, both groups had equal everyday cognition skills. The functionin
g of the phonological loop seems tb be clearly deficient in people with DS.
Interestingly, the deficit does not seem to affect the vocabulary or other
everyday cognition skills in individuals with DS. No signs of specific def
icit of the central executive component of working memory were found.