Memory coding in individuals with Down syndrome

Previous research has identified a deficit in phonological short-term memory in individuals with Down syndrome. The present work aimed to analyze how a group of 30 individuals with Down syndrome performed in a picture span task compared with 30 typically developing children of the same mental age. The task involved four conditions (i.e., dissimilar, phonologically similar, visually similar, and long-name items) chosen to analyze the strategy used by individuals with Down syndrome to code visually presented nameable items. Individuals with Down syndrome performed less well than typically developing children. Both groups showed the visual similarity effect. Taken together, our results confirm that individuals with Down syndrome have a verbal working memory deficit, even when nameable items are presented visually. Mental age appears to be an important determinant of memory coding stage in individuals with Down syndrome.