A Cognitive Test Battery for Intellectual Disabilities

The overarching goal of this project is to develop and validate an assessment battery to measure cognitive outcomes in clinical trials of individuals with intellectual disabilities. The project has arisen from our own preliminary studies in this area, and it will critically leverage efforts by the NIH Neuroscience Blueprint Toolbox consortium [6] which recently validated a computer administered cognitive battery (NIH Toolbox Cognitive Battery – NIH-TCB, www.nihtoolbox.org) normed in the general population for individuals between the ages of 3 and 89 years. Although the battery has great potential for ID, psychometric studies on this population are required. The cognitive battery will be piloted, refined and adapted if needed, and then formally validated utilizing groups of individuals with fragile X syndrome with ID (FXS-ID), Down syndrome with ID (DS-ID), and idiopathic ID (I-ID). The proposed research will benefit a wide range of studies aiming to assess or improve specific domains of cognition and general intellectual functioning in persons with ID. More generally, it will critically extend the utility of the NIH-TCB into populations of individuals with developmental and intellectual disabilities. Aim 1. To validate the NIH-TCB, including measures of executive function, episodic memory, working memory, processing speed, attention, and language, for individuals with ID, and modify it where necessary to meet the needs of this population. Aim 2. To examine the sensitivity of the NIH-TCB to detect clinically meaningful differences in persons with ID, including within-sample variation, detection of expected syndrome-specific cognitive phenotypes, and sensitivity to changes in cognitive growth on the measures across a two-year period. Aim 3. To examine the validity of the NIH-TCB composite scores (crystallized, fluid, and overall cognition) in ID groups compared with the established composites in general population controls, and to compare the psychometric properties of these composite scores to analogous gold standard measures of general intelligence (Stanford-Binet Intelligence Scales).