An investigation of cognitive overlap in working memory profiles in children with developmental disorders

• Some cognitive overlap in nonverbal IQ in developmental disorders (ASD, SLI, and ID).
• Some cognitive overlap in visuo-spatial working memory in developmental disorders.
• All 3 developmental disorder groups were distinguished by their severity of deficits.
• Developmental disorders do not have single, independent cognitive deficit.

We investigated the nature of cognitive independence or overlap between working memory and IQ in the following developmental disorder groups: Autism Spectrum Disorder (ASD), Intellectual Disability (ID), and Speech and Language Impairment (SLI). Participants were tested on standardized measures of IQ and working memory. The data indicates that there was some cognitive overlap in visuo-spatial working memory and nonverbal IQ. All three developmental disorder groups were distinguished by their severity of deficits: the SLI group performed in the normal range; the ASD group had scores in low-average range, and ID group scored below average. These findings correspond with evidence that developmental disorders do not have single, independent cognitive deficit. Clinical and educational support should be tailored accordingly.