Abnormalities shown to first appear in brain networks involved in sensory processing

August 29, 2017
This artwork shows a few of the connections in the brain of a typically developing 6-month infant who participated in the study. In the study, connections between all brain regions are generated, and the lengths and strengths of the connections are combined to determine the network efficiency of each region. Credit: Ludmer Centre

The origins of autism remain mysterious. What areas of the brain are involved, and when do the first signs appear? New findings published in Biological Psychiatry brings us closer to understanding the pathology of autism, and the point at which it begins to take shape in the human brain. Such knowledge will allow earlier interventions in the future and better outcomes for autistic children.

Scientists used a type of (MRI), known as diffusion weighted imaging, to measure the brain connectivity in 260 infants at the ages of 6 and 12 months, who had either high or low risks of autism. The lengths and strengths of the connections between was used to estimate the network efficiency, a measure of how well each region is connected to other regions. A previous study with 24-month-old children found that network efficiency in was lower in regions of the brain involved in language and other behaviours related to autism. The goal of this new study was to establish how early these abnormalities occur.

Lead author John Lewis, a researcher at the Montreal Neurological Institute and Hospital of McGill University and the Ludmer Centre for Bioinformatics and Mental Health, found network inefficiencies had already been established in six-month-old infants who went on to be diagnosed with autism. Inefficiencies in the six-month-olds appeared in the auditory cortex. He also found the extent of the inefficiency at six months of age was positively related to the severity of autistic symptoms at 24 months. As the children aged, areas involved in processing of vision and touch, as well as a larger set of areas involved in sound and language, also showed such a relation between inefficiency and symptom severity.

Identifying the earliest signs of autism is important because it may allow for diagnosis before behavioural changes appear, leading to earlier intervention and better prospects for a positive outcome. By pinpointing the brain regions involved in processing as the earliest known locations of neural dysfunction related to autism, researchers narrow down the genetic factors and mechanisms that could be responsible for its development. The fact that neurological signs are already present at six months also eliminates some environmental factors as potential causes of the disorder.

"Our goal was to discover when and where in the brain the network inefficiencies first appeared," says Lewis. "The results indicate that there are differences in the brains of infants who go on to develop even at six months of age, and that those early differences are found in areas involved in processing sensory inputs, not areas involved in higher cognitive functions. We hope that these findings will prove useful in understanding the causal mechanisms in autism spectrum disorder, and in developing effective interventions."

The research comes from the Infant Brain Imaging Study (IBIS), a collaborative effort by investigators at the Montreal Neurological Institute, and four clinical sites in the United States, coordinated to conduct a longitudinal imaging and behavioural study of infants at high risk for .

Explore further: Study identifies tools to identify patients at risk for autism spectrum disorders

More information: John D. Lewis et al, The Emergence of Network Inefficiencies in Infants With Autism Spectrum Disorder, Biological Psychiatry (2017). DOI: 10.1016/j.biopsych.2017.03.006

Related Stories

Study identifies tools to identify patients at risk for autism spectrum disorders

July 17, 2017
A tool intended to detect signs of autism in high-risk infants can be used to help identify and treat patients with tuberous sclerosis complex (TSC), a genetic disorder, who most need early intervention. Moreover, they can ...

Brain scans detect early signs of autism

June 27, 2012
A new study shows significant differences in brain development in high-risk infants who develop autism starting as early as age 6 months. The findings published in the American Journal of Psychiatry reveal that this abnormal ...

Autism severity detected with brain activity test

July 25, 2017
UCLA researchers have discovered that children with autism have a tell-tale difference on brain tests compared with other children. Specifically, the researchers found that the lower a child's peak alpha frequency—a number ...

Predicting autism: Study links infant brain connections to diagnoses at age 2

June 7, 2017
For the first time, autism researchers used MRIs of six-month olds to show how brain regions are connected and synchronized, and then predict which babies at high risk of developing autism would be diagnosed with the condition ...

Does having a sibling with autism affect a child's language and motor skills?

July 19, 2017
A review of published studies suggests that infants who have siblings with autism spectrum disorder may have less advanced linguistic and motor skills than siblings of children with typical development.

Brain network connections may underlie social behavior linked to autism

February 10, 2017
Evaluating the strength of connections in the brain is one avenue researchers have been exploring to help identify children at risk for autism spectrum disorder earlier in life.

Recommended for you

Social phobia linked to autism and schizophrenia

December 11, 2017
New Swinburne research shows that people who find social situations difficult tend to have similar brain responses to those with schizophrenia or autism.

Odors that carry social cues seem to affect volunteers on the autism spectrum differently

November 27, 2017
Autism typically involves the inability to read social cues. We most often associate this with visual difficulty in interpreting facial expression, but new research at the Weizmann Institute of Science suggests that the sense ...

Video game improves balance in youth with autism

November 21, 2017
Playing a video game that rewards participants for holding various "ninja" poses could help children and youth with autism spectrum disorder (ASD) improve their balance, according to a recent study in the Journal of Autism ...

Potential new autism drug shows promise in mice

November 14, 2017
Scientists have performed a successful test of a possible new drug in a mouse model of an autism disorder. The candidate drug, called NitroSynapsin, largely corrected electrical, behavioral and brain abnormalities in the ...

Relational factors in music therapy can contribute to positive outcome for children with autism

November 6, 2017
It might not surprise that good relationships create good outcomes, as meaningful relational experiences are crucial to all of us in our everyday life. However, the development of a relationship with a child with autism may ...

In autism, too many brain connections may be at root of condition

November 2, 2017
A defective gene linked to autism influences how neurons connect and communicate with each other in the brain, according to a study from Washington University School of Medicine in St. Louis. Rodents that lack the gene form ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.