A comparison of working memory abilities between children with intellectual disability with non-specific aetiology and children with Down syndrome in schools for intellectual development in Germany

ObjectivesThe study compares the working memory performance of students with Down syndrome (DS) to that of matched controls with non-specific intellectual disability (NSID). Even though empirical evidence is somewhat mixed and inconclusive, previous research suggests that students with DS display a relative weakness in the phonological loop. In contrast, no differences are reported in the visuo-spatial sketchpad and the central executive.MethodsThe sample consisted of 23 students with DS and 23 matched controls with NSID. The phonological loop was assessed using nonword repetition and picture span. Measures of the visuo-spatial sketchpad included a corsi-block task and a pattern span. Finally, an odd-one-out task was used to assess the executive-loaded working memory (ELWM) as a part of the central executive.ResultsSupporting our hypotheses, students with DS significantly differed from their peers with NSID in the phonological loop, while we found no performance differences for the visuo-spatial sketchpad and the ELWM.ConclusionsWeaknesses in the phonological loop in students with DS are documented in literature and supported by this study. Important conclusions can be drawn for teachers' instruction and students' reading development. However, the study's limitations mean that any inferences must be drawn cautiously.