Autistic girls were particularly understudied when we began this study in 2012. Fortunately, since we began data collection, people assigned female at birth have received increasing attention in autism research. The initial aim of the project was simply to learn more about the biology and behavior of children and adolescents assigned female at birth — in other words, to find and describe ways autistic girls might be similar to or different from autistic boys, and similar to or different from neurotypical girls.

Autistic and neurotypical children and adolescents took part in study visits where they participated in brain scans, donated blood for genetics analyses, took part in some behavior assessments, and completed surveys and questionnaires together with their parents.

One major finding from this study was that autistic girls seem to have differences in the striatal and motor systems of their brain versus both autistic boys and neurotypical girls. We saw that, on average, the group of autistic girls tended not to engage this brain system as much as neurotypical girls when processing simple movies of human motion. When we looked at genetic variations carried by autistic girls versus boys, autistic girls had larger sized rare variants containing genes that we think probably contribute to early development of the striatal region of the brain. Together, these brain and genetic findings make us think that differences in striatal development (and maybe motor development) are probably particularly important to autism in people assigned female at birth. The motor system is important for planning and executing movement, and the striatum interacts with the motor system to help connect information about what has value in the environment with the actions we would take to respond to that information.

This finding mostly serves to set the stage for future work more directly focused on improving well-being. For example, if autistic people assigned female are more likely to have differences in striatal development, this might mean that they would be more likely to experience certain kinds of health issues that involve the striatum. It might also mean that their autism might present in a way that “looks” slightly different to clinicians. So understanding striatal contributions to autism in people assigned female might help us make more accurate and timely diagnoses, or it could help us predict and address health challenges that might arise with age.

The cerebellum is an area at the back and bottom of the brain. Scientists used to think that it mostly helped people do things like walk and balance. Now we are learning that the cerebellum plays a part in lots of different kinds of thinking, feeling, and behavior. We wanted to learn whether the cerebellum helped other parts of the brain work well when viewing social information.

We also wanted to know if differences in how the cerebellum was working from person to person could help explain differences in their behavior.

Children, teens, and adults watched short videos of human motion, and scrambled versions of these videos, while they got an MRI brain scan. This let us understand what regions of their brain were active while they were viewing other people’s movements.

We found that the cerebellum was playing an important role in social information processing; both autistic and non-autistic people were using parts of their cerebellum while watching human motion. Differences in how participants were using their cerebellum were related to their age and social behavior.

It helped us get a better understanding of how a specific region of the brain (the cerebellum) works, and it showed us that differences between autistic people in terms of how they use their cerebellum might relate to their social behavior and development.

This study doesn’t directly impact autistic well-being right now. However, information we gained from this study helped us design a new study, which we are currently running, that has to do with how autistic teens use the cerebellum while they learn. We think that differences from person to person in terms of how their cerebellum developed, and how they are using it now, may help us understand why different autistic people show many different patterns of strengths and/or weaknesses in learning about different kinds of information. We hope that study could help us, in the long term, develop ways of supporting autistic students that meet their personalized learning needs.

This paper briefly summarizes major discoveries in autism neuroscience research over the past 40 years, and makes some suggestions about where the authors think autism neuroscience research should go in the future. Drs. Jack & McQuaid wrote the section of this paper about autism MRI research.

In our section of the paper, we emphasized current challenges in the field related to representation. Specifically, we talked about how neuroscientists who study autism need to do better at representing the diversity of the autistic community in future research, including, for example, nonspeaking people, people with intellectual disabilities, female and gender diverse individuals, and individuals from minoritized and/or non-Western communities. When these people aren’t included equitably in research, we aren’t able to equitably meet their needs.

This paper reviews research that other scientists conducted about three segments of the autism population that haven’t been frequently studied (especially using neuroimaging methods): minimally verbal people (so, people who can express very few words in any modality), people who experienced a developmental regression, and people with intellectual disability.

In this paper we highlight autistic people who have often been ignored in scientific research. Scientific research is often a foundation for providing needed services, which is why we are advocating for more scientific attention to these understudied segments of the population.