White Matter Microstructure and Atypical Visual Orienting in 7-Month-Olds at Risk for Autism

Abstract

Objective The authors sought to determine whether specific patterns of oculomotor functioning and visual orienting characterize 7-month-old infants who later meet criteria for an autism spectrum disorder (ASD) and to identify the neural correlates of these behaviors. Method Data were collected from 97 infants, of whom 16 were high-familial-risk infants later classified as having an ASD, 40 were high-familial-risk infants who did not later meet ASD criteria (high-risk negative), and 41 were low-risk infants. All infants underwent an eye-tracking task at a mean age of 7 months and a clinical assessment at a mean age of 25 months. Diffusion-weighted imaging data were acquired for 84 of the infants at 7 months. Primary outcome measures included average saccadic reaction time in a visually guided saccade procedure and radial diffusivity (an index of white matter organization) in fiber tracts that included corticospinal pathways and the splenium and genu of the corpus callosum. Results Visual orienting latencies were longer in 7-month-old infants who expressed ASD symptoms at 25 months compared with both high-risk negative infants and low-risk infants. Visual orienting latencies were uniquely associated with the microstructural organization of the splenium of the corpus callosum in low-risk infants, but this association was not apparent in infants later classified as having an ASD. Conclusions Flexibly and efficiently orienting to salient information in the environment is critical for subsequent cognitive and social-cognitive development. Atypical visual orienting may represent an early prodromal feature of an ASD, and abnormal functional specialization of posterior cortical circuits directly informs a novel model of ASD pathogenesis.

A Diffusion Tensor Imaging Study in Children With ADHD, Autism Spectrum Disorder, OCD, and Matched Controls: Distinct and Non-Distinct White Matter Disruption and Dimensional Brain-Behavior Relationships

“…The corpus callosum facilitates interhemispheric connectivity/ inhibition across the cortex (31). Corpus callosum structure in infancy predicts executive function in childhood and has been shown to correlate with tasks related to cognition in preschool-age children (32). Corpus callosum axons undergo extensive refinement in the postnatal period, and splenium fractional anisotropy increases rapidly over the first 10 years of life (33), a period that overlaps with the onset of NDDs.…”

The Relationship Between Fine Motor Skills and Social Development and Maturation

“…Stronger connections between the two cerebral hemispheres and the cerebellum lead to better fine motor skills. These stronger connections guarantee learning and optimization of brain functions, leading to more effective social interactions [3]. Hand movement skills can be considered an important factor in the development of social relationships.…”

Moving beyond behaviour-only assessment: Incorporating biomarkers to improve the early detection and diagnosis of autism spectrum disorders

“…Several recent studies have used prospective longitudinal designs to investigate brain structure in infants at high familial risk of developing ASD (Elison, Paterson, Wolff, Reznick, Sasson, Gu, et al, 2013;Shen, Nordahl, Young, Wootton-Gorges, Lee, Liston, et al, 2013;Wolff, Hongbin, Guido, Elison, Styner, Gouttard, et al, 2012). Using diffusion tensor imaging, Wolff et al (2012) identifi ed signifi cant qualitative differences in white matter development between high-risk infants who were diagnosed with ASD by 24 months, compared to those who did not receive an ASD diagnosis.…”

“…Using diffusion tensor imaging, Wolff et al (2012) identifi ed signifi cant qualitative differences in white matter development between high-risk infants who were diagnosed with ASD by 24 months, compared to those who did not receive an ASD diagnosis. Adopting a similar neuroimaging technique, Elison et al (2013) reported associations between the white matter structure of the splenium and visual orienting for typically-developing infants but not for highrisk infants who went on to show behavioural features of ASD. Shen et al (2013) presented consistent results from a study that used magnetic resonance imaging.…”