Premature babies don't use sensory-prediction brain process

Babies born prematurely do not use their expectations about the world to shape their brains as those conceived at full term do, according to a new study which offers clues to why such babies face higher risk of developmental delays as they grow.
Researchers, including those from Princeton University in the US, tested 100 babies, split between those born at full term and those born prematurely. The babies were tested at 6 months of age, based on their conception.
In 6-month-old babies born at-term, the portions of the brain responsible for visual processing respond not just to what the baby sees but also to what the baby expects to see.

That is a sign babies are learning from their experiences, said Lauren Emberson, assistant professor of psychology at Princeton.
However, babies born prematurely do not demonstrate that type of brain response to expectations, known as top-down processing.
"This helps bring together the picture that this type of processing is important for neural development," said Emberson.

"This also gives us insights into what might be going wrong in the case of prematurity. We believe this inability for learning to shape the brain is possibly one of the reasons," Emberson added.
The babies were exposed to a pattern that included a sound - like a honk from a clown horn or a rattle - followed by an image of a red cartoon smiley face.

The researchers used functional near-infrared spectroscopy, a technology that measures oxygenation in regions of the brain using light, to assess the babies' brain activity.
After exposing the infants to the sound-and-image pattern, the researchers began omitting the image sometimes.
In the full-term infants, brain activity was detected in the visual areas of the brain even when the image did not appear as expected, a sign of this top-down sensory prediction.
The brains of premature babies did not show this activity.
Emberson said this research sets the stage for continued work to understand how top-down processing helps babies learn better and how the lack of top-down processing relates to later developmental delays in the babies born prematurely.

For example, the first sign of a developmental delay for a child might come when they are not using any words at age two.
The study was published in the journal Current Biology.