Memory Consolidation in Adults With and Without Developmental Language Disorder and Dyslexia

Developmental language disorder (DLD) and dyslexia are common language-based learning disabilities that often co-occur, prompting debate regarding the nature of overlap in their learning and memory profiles. The current study examined how young adults with and without DLD or dyslexia learn and consolidate declarative, procedural, and speech-sound information over a 12-hour period. Participants completed learning tasks in the morning or evening and were retested on their performance after 12 hours. Declarative memory performance improved after 12 hours among evening-trained participants without DLD but not in morning-trained participants, nor in participants with DLD. Procedural memory performance improved after 12 hours among all participants without DLD, but not in participants with DLD. Sensitivity to the learned speech sounds improved after 12 hours across all participants. Together, these findings suggest that the time course of learning and consolidation differs across different types of learning and across different learning disability subtypes.