A non-drug, placebo-controlled study of the efficacy of a computer-based program to improve working memory in adolescents and young adults with Down syndrome.

Institution: Duke University, KKH Women’s and Children’s Hospital (Singapore)

Investigator(s): James Heller, M.A., Dr. Sriram Bhavani

Program: Cogmed RM, 8 weeks

Background & Aim: It is widely believed that individuals with Down syndrome have specific impairments in expressive language (the ability to formulate and express ideas), working memory (the ability to retain information during short periods of time) and executive function (management of responses). Sentence construction appears to be an area of particular weakness in expressive language and auditory memory has been identified as a particular short term memory problem.

Visual-spatial memory has been thought of as a relative strength, however this skill may be context specific, that is to say that individuals with Down syndrome appear to exhibit relatively fewer problems with visual-spatial memory in tasks requiring minimal cognitive control, however, as the demands on cognitive control increase, visual-spatial memory performance drops precipitously. In tasks requiring high cognitive control the relative deficit level of auditory memory and visual-spatial memory are comparable. Visual-spatial memory can be further broken down into visual tasks (requiring the memory of the visual properties of objects) and spatial tasks (requiring the memory of spatial relationships of objects).

Individuals with Down syndrome appear to have superior visual memory skills as compared to spatial memory. Memory and executive function deficits of individuals with Down syndrome have been associated with the neurologic impairment of the hippocampus (memory) and frontal lobes (executive function). Nerve densities in these areas of the brain are much less as compared to typically developing peers. The relationship between neurologic function and language deficit in Down syndrome has not been clearly delineated. It has been suggested that the language deficit may be related to and perhaps result from the working memory deficit. However, new brain imagining data suggest that language deficits seen in Down syndrome also may be directly linked to impaired hippocampus function.

The aim of this research is to determine if working memory deficits can be improved by Cogmed in adolescents and young adults with Down syndrome, as well as whether there is a differential effect of memory training on visual versus spatial memory and visual-spatial memory versus auditory memory. The learning performance profiles of the individuals with Down syndrome will be compared to the reported learning profiles of the school-age children with ADHD and the preschool children. Another aim is to determine if the learning achieved through Cogmed generalizes to other computer-based and non computer-based assessments of working memory, attention, reasoning and language function.

Population & Sample Size: N = 80 individuals with Down syndrome, ages 11-25 years, and a participating parent

Design: Randomized, Placebo controlled (2:1 ratio), Test-retest