The article, Multiple Components of Developmental Dyscalculia, challenges the idea that developmental dyscalculia (DD), a mathematical learning disability, stems from a single core deficit—most often proposed as a dysfunction in the Approximate Number System (ANS). Instead, the authors advocate for a multicomponent neurocognitive framework, emphasizing that DD results from the interaction of multiple cognitive impairments, not a singular cause.
Although the discovery of number-selective neurons in the intraparietal sulcus (IPS) of humans and primates initially suggested a biological basis for DD centered on number representation, recent research reveals a more complex picture. The authors highlight that DD often co-occurs with other disorders such as ADHD, dyslexia, and dyspraxia, pointing to the involvement of broader domain-general functions like working memory and attentional control.
Multiple brain regions and cognitive functions involved
Using fMRI data, the authors show that multiple brain regions, including the parietal cortex, inferior frontal gyrus, anterior cingulate, insula, and cerebellum, support number processing. These regions handle diverse tasks such as visual/auditory processing, semantic representation of quantities, cognitive control, and long-term memory retrieval. This complexity means impairments in any of these systems can lead to mathematical difficulties.
A critical component emphasized is working memory, especially its role in processing serial order and spatial information—both essential for understanding number magnitude and sequences. Behavioral phenomena such as the SNARC effect (associating small numbers with the left space and large numbers with the right) further illustrate the interplay between number cognition and spatial attention, potentially mediated by working memory.
The role of executive function and performance monitoring
Additionally, executive function, including inhibitory control and performance monitoring, is presented as another key factor. Evidence shows that children with DD often exhibit poor inhibitory control, leading to frequent errors in arithmetic. Neural mechanisms linked to performance monitoring, like activity in the anterior cingulate cortex and dorsolateral prefrontal cortex, are crucial for learning from mistakes—another area where children with DD may struggle.
