Scientists have identified differences in brain activity that explain why people with an Autism Spectrum Disorder (ASD) may endure social deficits and fail to respond appropriately when unexpected events unfold.
They found that an area of the brain called the gyrus of the anterior cingulate cortex (ACCg) signals when something surprising takes place for someone else, but individuals with ASD lack this typical response. This research therefore provides a novel insight into the biology underlying a condition that affects millions of people and isolates the ACCg as a target for potential therapies for ASD and other social deficit disorders.
The international team, which comprises scientists from Switzerland (ETH Zürich), Ireland (Trinity College Dublin), and the UK (Oxford University and Royal Holloway), has just published the research findings in the journal Brain.
The team was led by Dr Joshua Henk Balsters, who performed much of the research at Trinity. He said: “The ability to understand how other people make decisions and what happens to them as a result is key to successful social interaction. Unfortunately, individuals with ASD often find it very difficult to understand why the decisions of other people have the consequences that they do, and this can lead to social problems in everyday life.”
While being scanned in an MRI machine, individuals with an ASD and a group of age and IQ-matched volunteers had to think about the outcomes of their own decisions, about the results of another person’s decisions, and about the decisions made by a computer. Usually the outcomes of these decisions were exactly what people expected to happen, but the scientists were interested in the occasions where the outcomes were unexpected and surprising, particularly when they were unexpected and surprising for another person.
They then compared the brain signals in both experimental groups, and discovered a key difference in activity between the two.
Dr Balsters said: “A number of brain regions are activated when something unexpected happens, but there is a special part of the brain called the gyrus of the anterior cingulate cortex – the ACCg – that signals when something surprising happens to other people. We found that individuals with an ASD are less accurate at identifying other people’s expectations, but they also lack the typical response in the ACCg when surprising things happen to other people.”
“Additionally, we found that those with the greatest difficulties in social interaction –according to clinical measures — also show the least responsive ACCg. Given that brain responses in the ACCg correspond to social deficits in ASD, we hope that this will become a new therapeutic target. In the future we want to see whether pharmaceuticals or neurofeedback training, where we teach people to increase or decrease activity in this brain area, could complement existing behavioural therapies to improve social interaction.”