Approximately 6% of Americans suffer from the mathematical learning disability developmental dyscalculia (DD), facing academic difficulties, reduced employment, increased mental and physical illness, and higher rates of arrest and incarceration. Despite the potential consequences, no consensus currently exists regarding the brain and behavioral causes of DD. The project team will attempt to characterize the development of and interaction between brain mechanisms responsible for processing symbolic and nonsymbolic numbers in children from kindergarten through 2nd grade with DD, with the hope that understanding the root causes of the disorder will aid the development of effective diagnostic and remedial tools for educational interventions. They will engage in a combination of neuroscientific and behavioral research in order to disambiguate between competing causal theories that are unlikely to be distinguished on the basis of behavioral evidence alone. The project is supported by a CAREER award to Vanderbilt University by the EHR Core Research (ECR) program, which supports work that advances the fundamental research literature on STEM learning.
Competing theories of the underlying cause of DD suggest that there is a deficit either in the representation of numerical magnitude, or in the connection between those representations and symbolic numbers. The project will attempt to disambiguate between these theories by providing a multimodal characterization of the neural networks involved in basic nonsymbolic and symbolic number processing in DD children using functional magnetic resonance imaging (fMRI), as well as structural metrics of grey and white matter. The project will examine the development of those networks and will examine the extent to which those networks predict typical and atypical mathematical skill development. Investigators will study children with DD, children with dyslexia (DL), and typically developing (TD) children longitudinally from kindergarten to 2nd grade. By contrasting between these three groups, the investigators will be able to identify atypical brain and behavioral phenotypes that are specific to DD, as well as identify any commonalities between DD and DL. In each year, participants will complete a battery of symbolic and nonsymbolic number processing tasks in the fMRI scanner, in addition to a battery of behavioral tests measuring mathematics skills and general cognitive abilities. Measures of brain structure will also be collected in each year, allowing investigators to assess functional brain activation, functional and structural connectivity, and their relation to behavior and to each other. At the conclusion of the research project, the research team will provide evidence supporting a characterization of the core neurofunctional abnormalities in basic number processing underlying DD, identify the relationships between structural brain integrity and functional neural mechanisms underlying numerical magnitude processing in DD, and explore the causal developmental relationships beween aberrant number processing brain mechanisms and math outcomes in DD from kindergarten through 2nd grade.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
