Spatial Network Connectivity and Spatial Reasoning Ability in Children with Nonverbal Learning Disability

Abstract

(NVLD) is characterized by deficits in visual-spatial, but not verbal, reasoning. nevertheless, the functioning of the neural circuits supporting spatial processing have yet to be assessed in children with nVLD. We compared the resting state functional connectivity of a spatial brain network among children with nVLD, children with reading disorder (RD), and typically developing (TD) children. Seventy-five participants (7-15 years old) were included in the study (20 TD, 24 NVLD, and 31 RD). Group differences in global efficiency and functional connectivity among 12 regions comprising a previously defined spatial network were evaluated. Associations with behavior were explored. Global efficiency of the spatial network associated positively with spatial ability and inversely with socioemotional problems. Within the spatial network, associations between left posterior cingulate (pcc) and right retrosplenial cortical activity were reduced in children with nVLD relative to those without spatial deficits (RD and TD). Connectivity between left PCC and right posterior cerebellum (crus i and ii) was reduced in both groups of children with learning disabilities (nVLD and RD) relative to tD children. functional connectivity of the spatial network was atypically associated with cognitive and socioemotional performance in children with nVLD. identifying a neurobiological substrate for nVLD provides evidence that it is a discrete clinical entity and suggests targets for treatment. Nonverbal Learning Disability (NVLD) is a neurodevelopmental disorder characterized by deficits in spatial, but not verbal, reasoning. Children with NVLD frequently have accompanying impairments in socioemotional functioning, mathematical skills, executive function, and fine motor control 1-3 that may derive from their core deficit in spatial processing. Understudied is if NVLD is discrete from other neurodevelopmental disorders. For example, the social deficits associated with the disorder are often thought to overlap with Autism Spectrum Disorders (ASD). However, prior findings point to differing social deficits in the two disorders 1,2 that are subserved by distinct circuit alterations 4. A deeper understanding of the neural correlates of NVLD could provide evidence for recognizing NVLD as a discrete clinical entity. Spatial reasoning is a complex cognitive skill that relies on perception, memory, attention, and object recognition 5. The spatial deficit in NVLD encompasses problems in visuospatial awareness (e.g., awareness of own body in space), visuospatial construction (e.g., copying visually presented materials), visuospatial memory (e.g., remembering patterns and designs), spatial estimation (e.g., judging distance), three-dimensional thinking (e.g., imagining how things will look when rotated), interpreting information presented pictorially (e.g., reading maps) or visuospatial attention (e.g., visual scanning) 6-10. Spatial function is also known to associate with social function 11,12 , suggesting that the social impairment observed in NVLD ...

Altered structure and functional connectivity of the hippocampus are associated with social and mathematical difficulties in nonverbal learning disability

“…For individuals in the midrange, slight fluctuations in hippocampal volume may not result in changes in navigation ability due to the more central role of the retrosplenial cortex. Our prior findings that children with NVLD show reduced retrosplenial connectivity which associates with their PIQ further support this circuit‐based view (Banker et al, 2020).…”

Estimated Prevalence of Nonverbal Learning Disability Among North American Children and Adolescents

“…Such findings also suggest that these disorders may represent common comorbidities with NVLD. It is likely that the impairment experienced by individuals with NVLD differs from that in those with more typical anxiety or ADHD because the impairment in NVLD is thought to derive form underlying spatial deficits . Future research should begin to detail how spatial deficits manifest as functional impairments.…”

“…In addition, problems in visual-spatial memory, attention, visual executive functioning, fine-motor skills, and social skills are often present. This definition has been operationalized in previous empirical studies of the neuropsychological profile, 13 brain structure, 14 and function 15,16 of children with NVLD (Table 1).…”

How perception and attention participate in reading skill?

“…For optimal interaction with surroundings only a subset information or the relevant aspects of visual scene needs to be prioritized and reach the awareness (Kastner and Pinsk, 2004;Roach and Hogben, 2007). In brain, primary visual perceptions depend upon intact early visual areas and specific higher-order parietal areas (Pollen, 2011) with the visuospatial network (Banker et al, 2020;Diehl et al, 2014), visual filtering of posterior parietal cortex . Magnocellular system plays a role in visual discrimination (Ramus and Ahissar, 2012;Stein, 2014) where fast visual scene changes are processed (Livingstone et al, 1991) by inhibiting the parvocellular system (Stein and Walsh, 1997), or magnocellular being inhibited by the parvocellular system (Burr et al, 1994).…”