Parietal hyper‐connectivity, aberrant brain organization, and circuit‐based biomarkers in children with mathematical disabilities

Abstract

Mathematical disabilities (MD) have a negative life-long impact on professional success, employment, and health outcomes. Yet, little is known about the intrinsic functional brain organization that contributes to poor math skills in affected children. It is now increasingly recognized that math cognition requires coordinated interaction within a large-scale fronto-parietal network anchored in the intraparietal sulcus (IPS). Here we characterize intrinsic functional connectivity within this IPS-network in children with MD, relative to a group of typically developing (TD) children who were matched on age, gender, IQ, working memory, and reading abilities. Compared to TD children, children with MD showed hyper-connectivity of the IPS with a bilateral fronto-parietal network. Importantly, aberrant IPS connectivity patterns accurately discriminated children with MD and TD children, highlighting the possibility for using IPS connectivity as a brain-based biomarker of MD. To further investigate regional abnormalities contributing to network-level deficits in children with MD, we performed whole-brain analyses of intrinsic low-frequency fluctuations. Notably, children with MD showed higher low-frequency fluctuations in multiple fronto-parietal areas that overlapped with brain regions that exhibited hyper-connectivity with the IPS. Taken together, our findings suggest that MD in children is characterized by robust network-level aberrations, and is not an isolated dysfunction of the IPS. We hypothesize that intrinsic hyper-connectivity and enhanced low-frequency fluctuations may limit flexible resource allocation, and contribute to aberrant recruitment of task-related brain regions during numerical problem solving in children with MD.

Mechanisms of interactive specialization and emergence of functional brain circuits supporting cognitive development in children

“…Consistent with this view, greater IPS connectivity with the dlPFC, vlPFC and insula has previously been found in children with math disabilities. 58 Notably, in contrast to the findings from the present longitudinal study spanning 6 years, a cross-sectional study of 2nd and 3rd grade children (ages 7-8 to [8][9] found no changes in IPS connectivity over the period of 1 year. 59 Thus, the characterization of longitudinal growth trajectories over a longer time interval are necessary for detecting selective weakening of parietal-prefrontal circuits with age.…”

Challenging the neurobiological link between number sense and symbolic numerical abilities

“…[38][39][40][41] Furthermore, deficits in number sense are associated with irregularities in parietal structure and function. Individuals with dyscalculia are shown to have decreased gray matter, [42][43][44][45] atypical patterns of neural activation during the number comparison task, 46 and altered functional connectivity of parietal structures both at rest 47 and during arithmetic problem solving. 48 In addition to correlational studies, some research has attempted to provide causal support for the role of parietal mechanisms in processing numerical information.…”

Memory and cognitive control circuits in mathematical cognition and learning

“…4). Compared to their typically developing peers, children with MD show aberrant IPS connectivity with multiple prefrontal and parietal regions (Jolles et al, 2016). Specifically, children with MD show greater functional connectivity between left and right IPS, as well as between IPS and dorsolateral and ventrolateral PFC.…”