Working memory studies among individuals with intellectual disability: An integrative research review

Background Integrative research review infers generalizations about a substantive subject, summarizes the accumulated knowledge that research has left unresolved and generates a new framework on these issues. Due to methodological issues emerging from working memory (WM) studies in the population with non-specific intellectual disability (NSID) (N = 64) between 1990–2014, it is difficult to conclude on WM performance in this population. Aim This integrative research review aimed to resolve literature conflicts on WM performance among individuals with NSID and to identify the conditions/moderators that govern their WM performance compared to controls with Typical development. Method/procedure We used the six stages of integrative research review: problem formulation, data collection, evaluation, data analysis, results, interpretation and discussion. Outcomes and results The findings indicate two types of moderators that determine WM performance in the population with NSID: Participants’ moderators (criteria for matching the ID and TD groups, CA and MA), and task moderators [the three WM components of Baddeley and Hitch's (1974) model and task load]. Only an interaction between the two moderators determines WM performance in this population. The findings indicate a hierarchy (from more to less preserved) in WM performance of individuals with NSID: The visuospatial tasks, then some of the executive functions tasks, and the phonological loop tasks being less preserved. Furthermore, at a low level of control, the performance of participants with NSID was preserved beyond the modality and vice versa. Conclusions and implications Modality and MA/intelligence determine WM performance of individuals with ID. Educators should prepare intervention programs take the impact of the two moderators into account.