Brain’s electrical noise may explain communication struggles in autistic youths

• Researchers identified a biological clue in the brain’s electrical activity that may explain communication differences in autistic children.
• The study analyzed brain signals from 306 participants aged 7 to 18 using high-density EEG caps with 128 sensors.
• Autistic youths showed altered aperiodic brain signals indicating increased neural noise linked to less efficient speech processing.
• Youths with noisier brain activity tended to score lower on measures of everyday verbal communication.
• The finding is not yet a diagnostic tool but could lead to biological markers for evaluating autism interventions.

Parents and clinicians watch autistic children navigate a world of words with vastly different outcomes. Some speak fluently, while others struggle to express basic needs despite hearing the same language. Now, researchers at the University of Virginia believe they have identified a biological clue hidden within the brain’s electrical activity that could explain these differences.

Published in Scientific Reports, a new study from a multi-institutional team analyzed brain activity in 306 participants aged 7 to 18, including 162 youths with autism and 144 typically developing peers. Each child wore high-density EEG caps equipped with 128 sensors while listening to streams of spoken nonsense words designed to measure how the brain processes speech.

What the brain’s background signals may reveal

Rather than focusing on standard brain wave patterns, the team studied something less conventional: the brain’s “aperiodic” signal, a broader measure of neural activity that reflects the push and pull between excitation and inhibition — the mechanisms that help the brain sort meaningful information from static.

Autistic participants showed altered patterns in this signal, consistent with what researchers describe as increased neural “noise” — a sign that the brain may be working less efficiently to process speech. More significantly, youths whose brain activity appeared noisier also tended to score lower on measures of everyday verbal communication.

UVA neuroscientist Kevin Pelphrey, a co-author, explained the significance. “This is an important step toward understanding the neural mechanisms underlying communication in autism,” he said. “If we can identify reliable biological markers, they could eventually help researchers evaluate interventions more objectively and understand why communication abilities differ so widely across the autism spectrum.”

Jack Van Horn, a co-author and professor in UVA’s School of Data Science, highlighted the role of advanced computational methods. “The human brain generates an incredible amount of data every second,” Van Horn said. “The challenge isn’t collecting it anymore; it’s making sense of it.”

Why this isn’t a diagnostic tool yet

Researchers are careful to note this is not a diagnostic test for autism. Because most of the children in the study had average or above-average verbal skills, it’s still unclear whether the same brain patterns would show up in autistic youths who are minimally verbal — a question future research will need to answer. The authors also point out that EEG only measures brain activity indirectly, and pairing it with other imaging methods would give a clearer picture of what’s actually happening in the brain.

A step toward measuring the brain, not just behavior

Even so, the study pushes autism research a step closer to a goal that’s eluded scientists for years: a biological measure that can stand alongside, rather than replace, behavioral evaluations. The work included researchers from Seattle Children’s Research Institute, the University of Washington, Yale University, UCLA, and several other institutions.

For families dealing with the autism spectrum, this research offers a glimpse into a future where communication challenges might be measured biologically rather than solely through observation. While the data does not change what happens in classrooms or living rooms today, it points toward tools that could one day help researchers monitor changes in communication abilities over time or measure whether therapies are affecting underlying brain function.

The study appeared in Scientific Reports under the title “Altered aperiodic EEG spectral power during speech perception task is associated with verbal communication in youths with Autism Spectrum Disorder.” It was supported by the National Institute of Mental Health and the Autism Research Institute.

For now, the work stands as a reminder that the brain’s quietest signals may hold some of the loudest answers.

Sources for this article include:

ChildrensHealthDefense.org

MedicalXpress.com

Nature.com