Tuesday, February 27, 2018

Understanding "social brain" neural networks in autistic children

A team of researchers from the University of Geneva (UNIGE), Switzerland, studies how neural networks develop in brains of toddlers with autism. Their findings are published in the journal eLife.

As infants grow, they start reacting and responding to social cues like human gestures, voices, and faces. During this time their social brain develops. "Social brain" is part of the brain neural networks that respond to social cues.  It is well known that infants with Autism Spectrum Disorder (ASD) have lower attention and sensitivity during the first year and this is thought to ultimately influence normal development of neural networks related to the social brain.

Each dot represents the gaze position for an individual child watching the movie. The blue dots on the left represent the typically developing toddlers. The red dots represent toddlers with Autism Spectrum Disorders (ASD).
Credit: University of Geneva.
The study results show that therapies and interventions targeting children at an early age to develop the ability to respond to social cues could rewire neural networks of the brain when the brain is still elastic and programmable.

Dr Holger Sperdin, Postdoctoral Research Associate at the UNIGE's Faculty of Medicine and lead author of the study, explains what he and his team set out to discover: "As toddlers with Autism Spectrum Disorder (ASD) have less preferential attention for social cues, we hypothesised that when we showed them moving social images, they would demonstrate differences in both the way they visually explore these images and in the way their brain networks process social information, compared with typically developing toddlers."

The research team used electroencephalography (EEG) to monitor the children's brain activity, and powerful eye-tracking technology to observe their eye gaze while they watched movies featuring human social interactions. They found that the children with Autism Spectrum Disorder (ASD) had different gaze patterns while watching the movies to the typically developing infants and that this was accompanied by alterations in neural networks and information flow in the brain.

In those with Autism Spectrum Disorder (ASD), the team also observed what is known as 'increased driving' in two specific frequencies of brain waves alpha and theta as well as high levels of connectivity between nerve cells in certain regions in the brain. The theta brainwave frequency and the regions of the brain affected are both known to be important components of the "social brain", and the alpha frequency is important for visual attention.

These findings represent the first evidence that differences in the visual exploration of images coincide with changes in connectivity between critical regions of the social brain in very young children with Autism Spectrum Disorder (ASD). Brain regions generating these brainwave frequencies may, therefore, develop differently in children with Autism Spectrum Disorder (ASD) compared with their typically developing peers.

"Our results show for the first time the presence of alterations in information flow from brain areas involved in social cue processing in toddlers and pre-schoolers with Autism Spectrum Disorders (ASD)," concludes senior author Professor Marie Schaer, Assistant Professor at the University of Geneva, Switzerland. "These alterations within regions of the social brain are present at early stages of Autism Spectrum Disorder (ASD) and justify further investigation into whether therapeutic interventions targeting social orienting skills may help to remediate social brain development during this critical stage when neural plasticity is still possible."

Citation: Sperdin, Holger Franz, Ana Coito, Nada Kojovic, Tonia Anahi Rihs, Reem Kais Jan, Martina Franchini, Gijs Plomp, Serge Vulliemoz, Stephan Eliez, Christoph Martin Michel, and Marie Schaer. "Early alterations of social brain networks in young children with autism." ELife 7 (2018). doi:10.7554/elife.31670.

Adapted from press release by the University of Geneva.

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