A compensatory role for declarative memory in neurodevelopmental disorders

Abstract

Most research on neurodevelopmental disorders has focused on their abnormalities. However, what remains intact may also be important. Increasing evidence suggests that declarative memory, a critical learning and memory system in the brain, remains largely functional in a number of neurodevelopmental disorders. Because declarative memory remains functional, and because this system can learn and retain numerous types of information, functions, and tasks, it should be able to play compensatory roles for multiple types of impairments across the disorders. Here, we examine this hypothesis for specific language impairment, dyslexia, autism spectrum disorder, Tourette syndrome, and obsessive-compulsive disorder. We lay out specific predictions for the hypothesis and review existing behavioral, electrophysiological, and neuroimaging evidence. Overall, the evidence suggests that declarative memory indeed plays compensatory roles for a range of impairments across all five disorders. Finally, we discuss diagnostic, therapeutic and other implications.

Deficits in Coordinative Bimanual Timing Precision in Children With Specific Language Impairment

“…The procedural deficit hypothesis is based on Ullman's (2001Ullman's ( , 2004 declarative-procedural model, which posits that there are two distinct memory systems: the declarative memory system and the procedural memory system. The declarative memory system is responsible for learning, storing, and consciously recalling explicit knowledge, such as facts and events, as well as lexical knowledge (Ullman & Pullman, 2015). The medial temporal lobes, including the entorhinal, perirhinal, and parahippocampal cortices and the hippocampus, are the primary structures responsible for the development of the declarative memory system (Ullman & Pullman, 2015).…”

“…The declarative memory system is responsible for learning, storing, and consciously recalling explicit knowledge, such as facts and events, as well as lexical knowledge (Ullman & Pullman, 2015). The medial temporal lobes, including the entorhinal, perirhinal, and parahippocampal cortices and the hippocampus, are the primary structures responsible for the development of the declarative memory system (Ullman & Pullman, 2015). In contrast, the procedural memory system is responsible for the acquisition and use of new cognitive, perceptual, and motor skills (Viskontas & Knowlton, 2003) and is associated with phonological, morphological, and syntactic rule learning .…”

“…Children with SLI also exhibit performance decrements on nonlinguistic procedural tasks, such as statistical learning (e.g., Evans, Saffran, & Robe-Torres, 2009) and the serial reaction time task (e.g., Hsu & Bishop, 2014;Tomblin, Mainela-Arnold, & Zhang, 2007). In contrast, the acquisition of the lexicon, which relies more heavily on the declarative memory system (Ullman et al, 1997;Ullman & Pullman, 2015), is typically less affected in children with SLI (e.g., Lum & Bleses, 2012;Ullman & Pierpont, 2005). Thus, the procedural deficit hypothesis provides one framework for assessing common mechanisms that underlie motor and language deficits in children with SLI.…”

Untitled

“…The evidence so far suggests that declarative learning is preserved in children with LI 103 (Lum, & Conti-Ramsden, 2013) and that there is a compensatory role of this system in these 104 children (Ullman & Pullman, 2015). However, it could be that the preserved declarative learning 105 abilities of these children apply specifically to the processing of visual information (Baird, 106 Dworzynski, Slonims, & Simonoff, 2010) and not to verbal information.…”

“…They can even memorize high frequency phrases 125 and declarative rules, increasing declarative lexicon strategies, especially for complex linguistic 126 representations, compensating for the sequential learning deficit. Paradis and Gopnik (1997) 127 argue that children with LI rely on declarative learning strategies for the acquisition and 128 processing of syntactic information, which suggests a compensatory role of declarative learning 129 (for an explanation of the compensation hypothesis and its main arguments see the recent review 130 by Ullman & Pullman, 2015). 131 Specific linguistic ability differences have been found among children with LI depending on 132 their native language (Leonard, 2000).…”