An international team of scientists studying social deficits in individuals with autism spectrum disorders (ASD) has found significant differences in the way in which an area of their brain responds to unexpected situations.
The team from Trinity College Dublin (Ireland), ETH Zürich (Switzerland) and Oxford University and Royal Holloway (UK) found that an area of the brain called the gyrus of the anterior cingulate cortex (ACCg) signalled social prediction errors in typically developing individuals but that this signal was altered in individuals with ASD.
Social prediction errors are coding discrepancies between the predicted and actual outcome of another person’s decision and are thought to play a key role in understanding how others think and behave.
The study, published in the journal Brain, involved 16 individuals with ASD and 20 typically developing (TD) matched controls. Each participant was asked to play a choice game involving monetary awards while they were monitored in a MRI scanner. In each case the participant was led to believe that there would be a second player outside the scanner and a computer, both tasked with making similar choices in the course of the game. The study participants were then asked to indicate whether their outcomes and those of the second player and the computer were in line with their expectations or not. Unknown to them the second player was in fact a stooge who did not take part in the game. Instead in each case their choices were made by the computer.
The study found that individuals with ASD were generally less accurate at identifying both expected and unexpected outcomes compared to typically developing matched controls. However, the difference between ASD and TD accuracy was significantly larger for third person and computer trials compared to first person trials — i.e. those with ASD had greater difficulty monitoring the expectations and outcomes for other players than they did for themselves.
Lead researcher Dr Joshua Henk Balsters told RTE Radio that the team had targeted the ACCg area of the brain because they believe it is used to track other people’s thinking:
What we have done now is to make this more clinical and shown for the first time that people with autism don’t show the same brain signals in this area whilst they’re tracking other people’s actions and expectations.
Asked how the findings might help people with autism Dr Balsters described them as the first step.
We’ve got high hopes that we can change the intensity of that brain area either by using pharmaceuticals or by using some kind of neuro-feedback training, which is where you show the person their own brain activity and over weeks you can train them to naturally increase or decrease activity in that area.
Because in our study we showed there is such a tight relationship between the amount of activity in that brain area and how severe the social symptoms were in different individuals we think if we can teach them to increase or decrease activity in that brain area it could help to alleviate social symptoms.