Oculomotor dysfunctions, including accuracy, timing and sensorimotor processing, are promising endophenotypes for investigating the aetiology of neurodevelopmental conditions such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). This study compared 405 Australian children and adolescents with ASD, ADHD, both conditions (ASD + ADHD) and neurotypical controls using four oculomotor tasks: visual cued saccades, antisaccades, sinusoidal pursuit and step-ramp pursuit. Confirmatory analyses were performed with data from the UK and USA.
Results revealed that children and adolescents with ASD + ADHD showed greater variability in the final position of saccades during the guided visual saccade task, suggesting deficits in cerebellar and brainstem sensorimotor circuits. Participants with ASD showed a significant increase in corrective saccades during the step-ramp pursuit task, indicating impairments in corrective control and sensory integration.
The findings highlight that individuals with ASD + ADHD exhibit alterations in sensorimotor and inhibitory control networks, while individuals with ASD alone demonstrate more pronounced deficits in corrective control, possibly mediated by fronto-parietal and cerebellar networks. Such differences may provide new insights into the etiological and phenotypic mechanisms of these conditions, contributing to more accurate diagnostic strategies.
Keywords:
Autism Spectrum Disorder, ADHD, Neurodevelopment, Oculomotor Control, Endophenotypes.
Reference :
FORBES, EJ; TIEGO, J.; LANGMEAD, J.; UNRUH, K.E.; MOSCONI, MW; FINLAY, A.; KALLADY, K.; MACLACHLAN, L.; MOSES, M.; CAPPEL, K.; KNOTT, R.; CHAU, T.; MOHANAKUMAR SINDHU, VP; BELLATO, A.; GROOM, MJ; KERESTES, R.; BELLGROVE, MA; JOHNSON, BP Oculomotor Function in Children and Adolescents with Autism, ADHD or Co-occurring Autism and ADHD. Journal of Autism and Developmental Disorders, vol. 2025, p. 1–20, 2024. Available at: https://doi.org/10.1007/s10803-024-06718-3. Accessed on: January 27, 2025.
