Atypical brain network development of infants at elevated likelihood for autism spectrum disorder during the first year of life.

Researchers placed a soft cap with tiny lights on 5-month-old babies. The lights sent safe red light through the scalp. A camera tracked how the light changed. This shows blood flow in the brain.

The team studied babies who have an older sibling with autism. These babies have a higher chance of autism. They also studied babies with no family history. They wanted to see if brain networks looked different.

The high-risk babies had too many local connections. Their networks looked crowded. Messages moved slowly. The test told the groups apart with about 78 percent accuracy.

Low-risk babies had cleaner long-distance links. Their networks worked like open highways. The gap was already clear at five months.

Wagner et al. (2025) scanned the same babies again at nine months. They found the high-risk group still had odd brain answers when hearing speech. The new study adds language detail to the early network picture.

Bassett-Gunter et al. (2017) saw high-risk babies lose interest in speech sounds during the first year. Fen et al. now show the brain wiring behind that drop. Heart-rate and light-based measures tell one story.

Gandhi et al. (2022) reviewed 17 brain-and-language papers. They found no single pattern. The 2022 fNIRS result helps explain why: the first difference is network shape, not language spots.

You now have a five-month warning sign that is easy to collect. The cap weighs less than a hat. You can track siblings of clients you already serve. Spotting odd wiring early lets you start play-based intervention before delays show. Share the light-cap idea with pediatricians. Earlier entry means better outcomes for the whole family.