Brain organization underlying superior mathematical abilities in children with autism

Abstract

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social and communication deficits. While such deficits have been the focus of most research, recent evidence suggests that individuals with ASD may exhibit cognitive strengths in domains such as mathematics.

Methods: Cognitive assessments and functional brain imaging were used to investigate mathematical abilities in 18 children with ASD and 18 age-, gender-, and IQ-matched typically developing (TD) children. Multivariate classification and regression analyses were used to investigate whether brain activity patterns during numerical problem solving were significantly different between the groups and predictive of individual mathematical abilities.

Results: Children with ASD showed better numerical problem solving abilities and relied on sophisticated decomposition strategies for single-digit addition problems more frequently than TD peers. Although children with ASD engaged similar brain areas as TD children, they showed different multivariate activation patterns related to arithmetic problem complexity in ventral temporal-occipital cortex, posterior parietal cortex, and medial temporal lobe. Furthermore, multivariate activation patterns in ventral temporal-occipital cortical areas typically associated with face processing predicted individual numerical problem solving abilities in children with ASD but not in TD children.

Conclusions: Our study suggests that superior mathematical information processing in children with ASD is characterized by a unique pattern of brain organization and that cortical regions typically involved in perceptual expertise may be utilized in novel ways in ASD. Our findings of enhanced cognitive and neural resources for mathematics have critical implications for educational, professional, and social outcomes for individuals with this lifelong disorder.

Keywords: Autism; brain organization; cognitive strengths; mathematical abilities; multivariate pattern analysis; support vector machine.

Figure 1

Children with autism spectrum disorder (ASD) show significantly better mathematical abilities and sophisticated strategy use compared with their age-, gender-, and IQ-matched typically developing (TD) peers. (A) Standardized math achievement scores by group. Children with ASD performed better than TD children on the numerical operations subtest of the Wechsler Individual Achievement Test. (B) Discrepancy scores between standardized math measure and full IQ scores by group. Children with ASD displayed a bigger discrepancy score than TD children. (C) Different strategy use in ASD and TD. The groups differed significantly on the percentage of trials in which a decomposition strategy was used. Error bars indicate standard error of the mean. ^*p < .05. n.s., nonsignificant.

Figure 2

Brain activity patterns during arithmetic problem solving distinguish children with autism spectrum disorder from their typically developing peers. Multivariate pattern analysis revealed significant differences in spatial activation patterns between children with autism spectrum disorder and typically developing children in the (A) ventral temporal-occipital cortex: bilateral inferior lateral occipital cortex (LOC) and fusiform gyrus; (B) parietal cortex: left intraparietal sulcus (IPS), bilateral angular gyrus (AG), and left precuneus; and (C) medial temporal lobe: right entorhinal cortex and left hippocampus and parahippocampal gyrus.

Figure 3

Brain regions predicting numerical problem-solving abilities in children with autism spectrum disorder (ASD) overlap with face processing regions and cytoarchitectonically defined regional maps. Voxels in the left ventral temporal-occipital cortex, encompassing inferior lateral occipital cortex (LOC) and fusiform gyrus (shown in cyan), predicted better numerical abilities (R² = .69, q = .04, Cohen’s f ² effect size = 2.28) in children with ASD. (A) Voxels predicting better numerical abilities in ASD (cyan) showed prominent overlap with ventral temporal-occipital cortex face processing regions identified using Bayesian meta-analysis of 406 studies (blue) (www.neurosynth.org) (30). (B) Voxels predicting better numerical abilities in ASD (cyan) showed prominent overlap with cytoarchitectonically defined maps of the posterior fusiform gyrus, FG1 (green) and FG2 (violet) (31). (C) Maximum probability map (MPM) of the visual cortex. Other cytoarchitectonically delineated areas are abbreviated using the following nomenclature: hOc (human occipital cortex). Ordinal numbers 1 through 4 refer to the cytoarchitectonically defined visual areas moving laterally from the primary visual cortex (Brodmann area 17/primary visual cortex) (32). [Reproduced with permission from Caspers et al. (31)].