Reduced frontal gamma power at 24 months is associated with better expressive language in toddlers at risk for autism.
In high-risk toddlers, lower frontal gamma power forecasts stronger expressive language, turning the usual deficit story on its head.
01Research in Context
What this study did
Researchers placed a tiny EEG cap on 24-month-old toddlers who each had an older autistic sibling. They recorded brain waves while the kids listened to simple words. The team then compared the toddlers' frontal gamma power to their expressive language scores.
What they found
Kids with lower gamma power in the front of the brain spoke more words and longer sentences. The link held only for expressive language, not for understanding words.
How this fits with other research
Toth et al. (2007) saw the same group of high-risk toddlers score worse on language tests. The new finding flips that story: less gamma, not more ability, marks the kids who beat the odds. The difference is the measure—Karen watched behavior; L et al. watched brain waves.
Cox et al. (2015) found less resting gamma in older boys already diagnosed with ASD. Their lower gamma went hand-in-hand with more severe traits. Again, the toddler study points the opposite way, hinting that early low gamma may signal a protective or compensatory process before diagnosis.
Jouravlev et al. (2020) showed adults with ASD use both sides of the brain for language. The toddler gamma result adds a possible early marker: dampened frontal activity could start the pathway that ends in reduced lateralization.
Why it matters
You can’t strap an EEG on every toddler in clinic, but the finding tells you to look twice at the “quiet” frontal kids. If a high-risk young learners shows low gamma during a language task, celebrate the strength and pile on rich language input. Don’t assume delay; assume potential and intervene with extra conversation, modeling, and parent coaching.
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Join Free →When a 24-month sibling of an autistic child scores low on expressive language, add extra parent-mediated language turns instead of waiting—early low brain activity may flag hidden strength.
02At a glance
03Original abstract
Frontal gamma power has been associated with early language development in typically developing toddlers, and gamma band abnormalities have been observed in individuals with autism spectrum disorder (ASD), as well as high-risk infant siblings (those having an older sibling with ASD), as early as 6 months of age. The current study investigated differences in baseline frontal gamma power and its association with language development in toddlers at high versus low familial risk for autism. Electroencephalography recordings as well as cognitive and behavioral assessments were acquired at 24 months as part of prospective, longitudinal study of infant siblings of children with and without autism. Diagnosis of autism was determined at 24-36 months, and data were analyzed across three outcome groups-low-risk without ASD (n = 43), high-risk without ASD (n = 42), and high-risk with ASD (n = 16). High-risk toddlers without ASD had reduced baseline frontal gamma power (30-50 Hz) compared to low-risk toddlers. Among high-risk toddlers increased frontal gamma was only marginally associated with ASD diagnosis (P = 0.06), but significantly associated with reduced expressive language ability (P = 0.007). No association between gamma power and language was present in the low-risk group. These findings suggest that differences in gamma oscillations in high-risk toddlers may represent compensatory mechanisms associated with improved developmental outcomes. Autism Res 2019, 12: 1211-1224. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: This study looked at differences in neural activity in the gamma range and its association with language in toddlers with and without increased risk for ASD. At 2 years of age, gamma power was lower in high-risk toddlers without ASD compared to a low-risk comparison group. Among high-risk toddlers both with and without later ASD, reduced gamma power was also associated with better language outcomes, suggesting that gamma power may be a marker of language development in high-risk children.
Autism research : official journal of the International Society for Autism Research, 2019 · doi:10.1186/1744-9081-7-30