Some autistic teens often adopt behaviors to mask their diagnosis in social settings helping them be perceived — or "pass" — as non-autistic. For the first time, researchers are able to observe brain functions that differ in those who "pass as non-autistic," which could lead to a better understanding of the cognitive toll of this kind of masking, and of how these individuals could be more effectively supported.
Using an electroencephalogram (EEG) to measure brainwaves, researchers from Drexel University's A.J. Drexel Autism Institute found that teens who pass as non-autistic in school settings showed faster automatic responses to faces and reduced emotional reactivity to subtle emotional facial expressions. This finding could play a key role in ensuring autistic teens, who may not feel comfortable revealing their diagnosis, can still receive the support they need to thrive.
"This suggests that their brains may be wired to quickly recognize social cues while dampening emotional responses, either as a preparatory or coping mechanism," said Matthew Lerner, PhD , associate professor, leader of the Life Course Outcomes Research Program, and director of the Social Connections and Treatment Lab in the Autism Institute and lead author of the study. "These findings offer the first direct evidence of how brain activity might differ in those who pass as non-autistic, shedding light on the hidden mental effort behind social masking in autism. The findings could reshape how we understand the mental toll of masking."
The study, recently published in Scientific Reports , revealed that 44% of community-recruited autistic teens passed as non-autistic in the classroom – meaning their teachers would not have noticed or identified them as autistic. Those who were in the "passed as non-autistic" group showed faster initial brain response when looking at faces and showed less emotionally reactive brain response to subtle emotions in faces.
Lerner explained that these findings reveal, for the first time, some of the ways in which autistic teens who pass as non-autistic process social information in unique ways, which differ both from non-autistic teens and autistic teens who do not pass as non-autistic. These findings also suggest that there may be more autistic teens who pass as non-autistic than previously thought, though larger-scale research is needed to support this.
These datasets were collected as part of a larger National Institute of Mental Health-funded study examining factors impacting social outcomes in autistic teens. Importantly, this study focused on recruiting a broad population from the community, including those who did not necessarily have an autism diagnosis in advance. Lerner added that this allowed for inclusion of teens who meet criteria for autism by formal diagnostic processes but may not otherwise have an existing diagnosis or supports in schools.
The research team explained that the "passing as non-autistic" group was identified by looking at the difference between autism features as displayed in a gold-standard diagnostic setting and those displayed in classrooms (according to teachers) and at home (according to parents).
"This allowed for more clearly defining what we mean by 'passing,' because those youth who did so both unambiguously met criteria for autism by gold-standard measures and did not show any significant hints of autism in the classroom according to their teachers," said Lerner.
The EEG measurements were taken during a standardized procedure where participants were shown a set of faces and asked to rate their emotion.
Their event-related potential responses — the small "blips" in the brainwave that indicate a brain's response to stimuli (the faces) — provided information about how a person differentiates a face from a non-face object, and how a person regulates their emotional response to a stimulus.
"We hope this will spur greater inquiry into identifying autistic youth who are 'passing as non-autistic,' determining what cognitive efforts are involved in this, and developing improved ways to support the lives of those who are doing so," said Lerner.
The full report can be read here: https://www.nature.com/articles/s41598-025-04801-y .
