The Brain’s Response to Faces Predicts Social Development in Autistic People | Spectrum
A delayed brain response to the visualization of faces can predict delays in social skills development in people with autism, according to an unpublished study, suggesting the response could be used as a biomarker for autism.
The researchers presented the findings virtually today at the 2021 annual meeting of the International Society for Autism Research. (Links to abstracts may only work for registered conference attendees.)
Because autism traits vary widely, researchers regularly look for ways to group study participants with similar traits and support needs. Such “layering biomarkers” could allow researchers to better target therapies or predict individual responses to drugs, says researcher Emily Jones, professor of translational neurodevelopment at Birkbeck, University of London in the UK.
“People with autism tell us they don’t want us to change their personality or the way they experience their autism, but there may be more specific things they want help with,” Jones says. “One of the reasons we’re interested in stratification markers is to find markers of things people with autism want support or treatment for.”
One such biomarker could be a brain response called “N170 event-related potential,” a spike in electrical activity that occurs about 170 milliseconds after a person has seen a face. This response is often delayed in autistic people compared to non-autistic people. The discovery is one of the reasons the U.S. Food and Drug Administration take into account the use of N170 as a biomarker in clinical trials.
Delays in the N170 response could help identify children who would benefit from more help developing social skills — such as group play — that are important for quality of life, Jones says.
“We find consistent evidence that at least there’s something to looking at these traditional measures of the social brain,” Jones says.
Jones’ team used electroencephalography to measure the N170 response in 246 autistic and 190 non-autistic people aged 6 to 31 as they looked at pictures of faces. The researchers also imaged the participants’ brains during the task using functional magnetic resonance imaging and asked the participants’ parents to complete a survey assessing daily social skills. The participants, who are part of the European Autism Longitudinal Project, repeated the tests one to two years later and also provided genetic data.
On average, people with autism had more delayed N170 responses than people without autism. Regardless of group, people who had more autism-linked genetic variants had slower N170 responses, and people with slower responses had less activity in the fusiform gyrus, a part of the brain involved in social treatment.
Among autistic participants, those with slower N170 responses were less likely to show gains in social skills on the second assessment than those with faster responses. After grouping participants based on their neural responses, the researchers found that about 10% of people with autism belonged to a group with slow N170s and little improvement in social skills.
The work is a first step toward translating research findings into useful clinical measures, Jones says. Researchers need to replicate findings in larger groups and establish guidelines for when a biomarker might be implemented.
“We’ve crafted a path to ask these questions,” Jones says. “If we wait forever for the perfect signal, we don’t do people any good either.”
Read more reports of the 2021 International Autism Research Society annual meeting.