Differences in Neural Correlates of Speech Perception in 3 Month Olds at High and Low Risk for Autism Spectrum Disorder.

Researchers placed EEG caps on 3-month-old babies. Some babies had an older sibling with autism, putting them at high risk. Others had no family history.

The team played the same syllable over and over while recording brain waves. They watched for habituation—when the brain stops reacting to a repeated sound.

Low-risk baby girls quickly tuned out the repeated sound. Their brain waves showed clear habituation.

High-risk baby girls never tuned out. Their brains kept firing as if each syllable were new. Boys showed no clear group difference.

Gabard-Durnam et al. (2015) saw a similar sex-specific EEG pattern at 6 months. They tracked alpha waves instead of habituation, but both studies flag girls first.

Camodeca et al. (2020) followed 9-month speech preference through toddler language. Their work extends the timeline: early speech quirks can shape later talking.

Pfadt (1991) looked at autistic toddlers and found many ignored their mother’s voice. That sounds opposite, but the kids were two years older. Neural signs at 3 months can flip to behavioral avoidance by 24 months.

You can’t pop an EEG cap on every baby, but you can watch for signs during parent coaching. If a 3-month girl at high risk never zones out from your repeated cooing, note it. Share the clue with the pediatrician and schedule closer monitoring. Early red flags let you start turn-taking games and rich language input before delays pile up.