2-month-olds see the world in a more complex way than scientists thought, study suggests

A new study suggests that babies are able to distinguish between the different objects they see around them at 2 months old, which is earlier than scientists previously thought.

The findings, published Monday in Nature Neuroscience, may help doctors and researchers better understand cognitive development in infancy.

“It really tells us that infants are interacting with the world in a lot more complex of a way than we might imagine,” said lead author Cliona O’Doherty. “Looking at a 2-month-old, we maybe wouldn’t think that they’re understanding the world to that level.”

The study looked at data from 130 2-month-olds who underwent brain scans while awake. The babies viewed images from a dozen categories commonly seen in the first year of life, such as trees and animals. When babies looked at an image like a cat, their brains might “fire” a certain way that researchers could record, O'Doherty said. If they looked at an inanimate object, their brains would fire differently.

The technique — known as functional magnetic resonance imaging, or fMRI — allowed scientists to examine visual function more precisely than in the past. Many previous studies relied on how long an infant looked at an object, which can be difficult to assess at younger ages. Some of those past studies suggested that infants as young as 3 to 4 months could distinguish between categories such as animals and furniture.

“What we’re showing is that they really already have this ability to group together categories at two months,” O'Doherty said. “So it’s something much more complex than we would’ve thought before.”

In the new study, many of the babies returned at 9 months, and researchers successfully collected data from 66 of them. In the 9-month-olds, the brain was able to distinguish living things from inanimate objects much more strongly than in the 2-month-olds, O'Doherty said.

Someday, researchers said, scientists may be able to connect such brain imaging to cognitive outcomes later in life.

Liuba Papeo, a neuroscientist at the National Center for Scientific Research in France, said the number of babies in the study is one thing that makes the work “impressive and unique.” Brain imaging with very young infants presents challenges.

“One — perhaps the most obvious — is that the infant needs to (lie) comfortably in the fMRI scanner while awake without moving," she said in an email.

O’Doherty, who did the work at Trinity College Dublin in Ireland, said the key was making the experience as comfortable as possible for the babies. Inside the scanner, they reclined on a bean bag so they were snug.

The images “appear really big above them while they’re lying down,” she said. "It's like IMAX for babies.”

AP video journalist Havovi Todd contributed to this story from London.

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