Most people possess a standard functional brain organisation, where the right hemisphere is associated with emotion and processing of faces while the left hemisphere is dominant for fine motor control.
An example of this has been observed in what is known as the “left-cradling bias”, where humans typically cradle a baby on their left side – as information from the left visual field is processed by the right hemisphere of the brain.
But in experiments using dolls, scientists found that children who have autism were more likely to cradle the toy on their right side rather than the left, indicating a reversed brain organisation or a “mirroring of the standard template”.
The researchers say the findings, recently published in the journal Scientific Reports, could help in identifying children at risk of neurodevelopmental disorders much earlier than current diagnostic practices allow.
Dr Gillian Forrester, of Birkbeck, University of London – who led the study, said: “Brain and behavioural biases are key to understanding how brains develop.
“They can also help doctors spot children at risk of neurodevelopmental disorders, like autism, earlier than current diagnostic practices allow, enabling them to put in place support at a younger age to improve their outcomes.
“The reversal from the typical pattern may explain why children with autism have difficulties with their social and communication skills.”
Nearly 200 children, aged between four and five, took part in the small study, half of whom had autism.
They performed cradling tasks using pillows and gender-neutral dolls.
The children were also tested on their fine motor skills, which involved assessing their pincer grip ability to determine hand preference.
Each child’s social and communication abilities was assessed individually by teachers.
Dr Forrester and her team found children who were typically developing were more likely to possess a standard brain organisation for social and communication abilities, whereas those with autism showed a “significant rise” in reversed organisation, associated with decreased skills in these areas.
Typically developing children were also found to have a left hemisphere that was dominant for fine motor control, meaning they were more likely to be right-handed.
However, the researchers said that left-handedness on its own was not associated with decreased cognitive ability or autism but can rather “act as a marker for decreased cognitive performance when paired with reversed brain organisation”.
Dr Forrester said identifying children with reversed brain organisation could help in designing early interventions that could “target the overriding area of the neurodevelopmental disorder”.
She added: “We now have an opportunity to develop new and innovative diagnostic tools and therapeutic interventions that target gaze behaviour much earlier in life in the hopes of decreasing the severity of the social deficits associated with the condition.”