Children with autism spectrum disorder (ASD) look less often at other people’s faces than children without the disorder, and a new study has found that when the brain’s visual system does not develop normally, possible irregularities that occur can alter the way some babies interpret their environment and interact with other people, further affecting brain development and potentially predisposing them to developing autism.
When parents and infants are together they tend to look into each other’s eyes in a process that provides infants with a way to learn to interpret subtle visual cues in the environment, influencing how they learn to relate a caregiver’s behaviors to their own and It is essential during the first years of life for the cognitive, emotional and social development of children. The results of the new study, which has been published in the American Journal of Psychiatry, suggest that something is wrong with the brain’s visual system and that this affects this visual interaction in babies who develop autism.
The research has been conducted by scientists at Washington University School of Medicine in St. Louis and the University of North Carolina School of Medicine, who have identified certain abnormalities in the development of the brain’s visual system in infants that can contribute to the development of ASD. To carry out the study, brain MRIs were performed on 384 babies who had a high risk of autism because they had older siblings with ASD.
Alterations in the visual system and severity of autism traits
About 25% of the babies in the study were diagnosed with autism. Brain scans showed abnormalities in the size, white matter, and functional connectivity of the infants’ visual systems, and these irregularities were present long before autism symptoms were detected. “These abnormalities in the visual structures of the brain follow very well with our previous research on eye movements in children with autism,” said John N. Constantine, MD, Blanche F. Ittleson Professor of Psychiatry and Pediatrics and Director of the Division of Child and Adolescent Psychiatry at the University of Washington and one of the lead authors of the study.
“In previous research -he continues- we noticed that children with autism often look less at people’s faces than children without the disorder. In this study, we have seen that abnormal development of the visual system may have its roots in genetics because the extent of disturbances in the visual systems in children up to six months of age was associated with the severity of autistic traits in their children. Older brothers”.
Brain scans showed abnormalities in the size, white matter and functional connectivity of the infants’ visual systems, present long before symptoms of autism were detected
They also measured brain volume and surface area in the occipital cortex — a brain region involved in vision — and examined white matter in a part of the brain previously linked to how infants track visual stimuli. in the environment, and autistic traits were documented in older siblings. The researchers found that brain characteristics related to the structure and function of the visual system in six-month-olds who developed autism by their second birthday were different from those in infants who did not develop autism.
“It is particularly remarkable that we were able to demonstrate associations between the brain findings in these infants and the behavior of their older siblings with autism,” said Dr. John R. Pruett Jr., a professor of psychiatry at the University of Washington and co-senior author. “The convergence of whole-brain fcMRI results with diffusion and structural MRI findings strengthens our confidence in these discoveries, which can now be tested in a new group of 250 infants who are being recruited for another study because they have affected to siblings and they have a very high probability.”
While the paper’s authors acknowledge that more study is needed, they also say the findings suggest that behavioral interventions targeting the visual system may be possible to try to reduce the likelihood that children will develop some of the more severe features associated with the disorder. Autistic spectrum.
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