How traits relate to mind exercise could differ between autistic boys, ladies | Spectrum
Biomarker Bias: Brainwave patterns in autistic boys, but not autistic girls, appear to correlate with traits.
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Autistic children show a distinct pattern of resting brain activity, and how that pattern relates to behavior differs between autistic boys and girls, according to a new study.
Previous analysis suggests that characteristics of autism differ between boys and girls. But fewer girls are diagnosed with autism and included in the research, in part because the diagnostic ratings on boys are tested and biased.
Consistent with this bias, studies examining resting brain activity as a possible biomarker of autism have been small and have not looked at whether this activity varies by gender, says Sunil Mehta, a psychiatrist specializing in autism and other neurological conditions at the Mayo Clinic in Rochester, Minnesota. Mehta was not involved in the work.
The new work supports the idea that the brains of autistic boys function differently than those of autistic girls. It should also serve as a warning for scientists to be aware of these differences when looking at resting brain activity as a biomarker of autism, the researchers say.
“We cannot assume that what we learn about men with autism also applies to women with autism. That may sound obvious, but girls and women too [autism] are often underrepresented in research samples, so researchers have not rigorously investigated whether and how their findings apply to women, “says study researcher Emily Neuhaus, assistant professor of psychiatry and behavioral science at the University of Washington in Seattle.
Neuhaus and her colleagues at four US sites used electroencephalography (EEG) to measure resting brain activity in 81 boys and 61 girls with autism and 70 boys and 68 girls without autism. All participants were 8 to 17 years old and had average or above average cognitive abilities.
Participants watched a short film and then sat quietly with their eyes closed while the researchers recorded the “performance” of their brain waves – which reflect activity levels – at five frequencies and in nine brain regions. The team also assessed the children’s social, communication and everyday skills using standard questionnaires completed by parents.
Compared to neurotypical children, those with autism showed lower performance in a frequency band called alpha. Alpha power, which is inversely linked to neural activation and to attention and sensory control, could show promise as an autism biomarker, the researchers say. This power difference may mean that the autistic children experienced the assigned resting state activity as an explicit task.
“Your data suggests that asking people on the spectrum to actually do something that is quiet for most people does actually take effort and attention,” says Mehta. “It is important for the field to recognize that the task is very important in the context.”
Only in autistic boys did lower performance in the theta, beta, and alpha frequency bands correlate with stronger social skills. These brain waves reflect cognitive functions such as memory and attention. The study shows that higher gamma performance – which reflects, among other things, sensory responses and working memory tasks – is tracked with lower nonverbal IQs and more repetitive behaviors.
In contrast, autistic girls’ brainwave patterns did not correlate with their skills or behavior. The results were published in September in the Journal of Neurodevelopmental Disorders.
Researchers aren’t sure why these differences exist.
“It could be that boys and girls use different strategies to find their way around the same social situations, or actually use different circuits in the brain, which is reflected in the EEG,” says Mehta.
The results suggest that researchers “need to pay much more attention to the differences between autistic men and women,” says Emily Jones, a professor of translational neurodevelopment at Birbeck, University of London in the UK who was not involved in the work.
The underrepresentation of autistic girls in research “can certainly contribute to inequalities in access to health care, diagnosis and support services,” she says.
Understanding how differences in gender and gender can affect the development and expression of autism “requires studying this ability from the start,” says Neuhaus.
“We need to think within the autism community about how some people can be represented by a certain study result and others not,” adds Neuhaus. “If we don’t do this, we run the risk of developing theoretical models of autism, diagnostic tools, or intervention approaches that are not appropriate for the people who were not represented in this research.”
Quote this article: https://doi.org/10.53053/BMRZ8213