Balancing act: what motor function can tell us about autism

By Peter Jurich | Waisman Communications

Can the way a person moves be a key identifier of autism?

Brittany G. Travers, PhD
Brittany G. Travers, PhD

It’s a question that Waisman Center investigator Brittany Travers, PhD, is trying to answer. A new paper from Travers’ lab suggests that movement patterns of individuals with autism spectrum disorder (ASD) may differ from those with typical development. This opens the door to a more nuanced understanding of how individuals with ASD move in space and how this movement may be similar or different to that of people without ASD.

In this paper, “Whole Body Movement during Videogame Play Distinguishes Youth with Autism from Youth with Typical Development,” which was published in the December 2019 issue of the journal Scientific Reports, Travers and her team looked at the movement patterns of individuals with autism compared to the movement patterns of individuals with typical development. Travers and her team created a machine learning algorithm to distinguish between the groups. Machine learning is a form of artificial intelligence that uses computer programs to analyze data quickly and efficiently.

“Our work, and the work of others, has shown that there are motor challenges that are commonly present in people with autism,” Travers says. “It’s almost like any motor activity we test, we usually find some type of group difference. We wanted to see if we’re actually able to find a motor signature that was unique to people with ASD and to explore what areas of the body were responsible for movement differences.”

Travers thinks it is important to study motor skills in people with autism because previous work from her and other labs have suggested that motor challenges are strongly linked to daily living skills.

Also, motor skills may provide unique insights into how the brain is wired in people with ASD,” she says. “By understanding motor patterns, we might be able to better understand how to remove barriers to independent living for people with ASD.”

Finding equilibrium

Balance involves many different neurological systems working together, which is why Travers calls it a “whole-brain phenomenon. “All the ways that our brain is connected and working together to just keep us standing is something that we often take for granted,” says Travers.

The purpose of Travers’ study was threefold: first, to see if motor function could be used to distinguish individuals with ASD from those without; second, to determine whether those differences in motor function were specific to certain demographics; and third, to highlight which areas, if any, were the most informative in identifying those differences.

For this study, researchers used both a Nintendo Wii balance board and a Microsoft Kinect — an Xbox motion sensor accessory that allows players to use their whole bodies to play certain video games. While standing on the Wii balance board, study participants would hold several different positions for up to four minutes at a time and the Microsoft Kinect recorded how well

they held each position. Sessions were 25 minutes each, three times a week for six weeks. The study also involved cognitive, motor, and diagnostic testing, and brain imaging. “We knew that if we wanted to ultimately elicit brain changes, training would probably have to be pretty intensive,” Travers says.

A great deal of her research involves playing video games, which is ironic because, in her own words, she’s terrible at them. However, video games have proven to be an effective tool for research as indicated in this recent paper.

They are also a draw for youth. Travers calls it “a spoonful of sugar approach” to encourage intensive balance training.

“I know that physical activity is really good for me, but I’m not always feeling motivated to, for example, go for a run,” she says. “So there are ways that we can make these things motivating because if they’re not motivating and rewarding, people aren’t likely to do them. With video games, there are really concrete goals and that is something that I think makes gaming really interesting to a number of us.”

Travers story graphic
Study setup. Microsoft Kinect camera and Wii Balance Board send the joint kinematic and postural sway data to the computer, which controls the biofeedback-based balance training game and records the data.

The importance of motor function

Travers’ latest paper builds upon an entire career that sits at the intersection of motor function and neurobiology in individuals with ASD. Her early work as a graduate student showed that people with unstable postures have more severe autism symptoms. Even then, she was using that same Wii balance board — a Christmas gift from years ago — with similar research methods that use highly physical video games to improve balance.

For this study, Travers and her team developed a machine learning algorithm that could distinguish among joint positions on the participants’ bodies to see if any one particular area moved more distinctly in individuals with autism. They found that the motor differences were part of what she calls “a whole body condition,” with feet, elbows, wrists, shoulders and head being most informative areas; those were the areas that showed the most variability of movement. The paper was then able to conclude that “whole-body gross motor features… appear to be a distinctive feature between diagnostic groups.”

So reliable were those areas in distinguishing between individuals with and without autism, that the algorithm was able to identify the groups with up to 89 percent accuracy. Within that 11 percent who were misidentified, many were typically developing participants under the age of 14 grouped in with older teens with autism.

Travers says this tells us about the nature of motor challenges in autism. “We think this tells us that the autism motor profile might not be something that is qualitatively distinct, but it might be more representative of a motor delay,” she says.

Whichever it is, one of Travers’s end goals remains “to translate the knowledge of motor function and neurobiology to develop occupation-based interventions specifically suited to youth with ASD.” By doing this, she hopes to remove what she calls “motor barriers,” that may prevent one from realizing a better quality of life.

“We are working on one type of intervention right now — our balance videogame intervention — but it is an open question about what type of motor intervention would best facilitate enhanced daily living skills in ASD,” she says. “Interventions that combine both daily living skills and motor components may be the most efficacious, but that is just speculation at this point. We hope to test this in the future — and take the impactful scientific steps to get there.”