Infant Observers

Babies have a tough job—not just figuring out the world in general, but the behaviors and peculiarities of their fellow humans, too.

How do they do it? Researchers from Maryland and the University of Chicago recently tried to answer that question by fitting 36 boisterous 7-month-olds with electroencephalogram (eeg) caps to monitor their brain activity while interacting with other people at UMD’s Child Development Lab.

In the experiment, babies watched an adult reach for one of two toys, and then were allowed to grab one of the toys for themselves, with the procedure repeated 12 times.

As the researchers reported in Psychological Science, the EEG “window” into the baby’s brain predicted how the baby would respond. If the part of the brain that controls motor activity fired up while watching the adult, the baby would grab for the same toy. If it didn’t, there was no imitation.

The study is the first in which a baby’s brain activity was shown to predict imitation behavior, and is just “one piece in a larger puzzle of understanding neural networks,” says the study’s senior author, Courtney Philippi, who conducted the research as a University of Chicago Ph.D. student. 

Co-author Nathan Fox, a UMD professor of education and head of the Child Development Lab, said many related questions remain to be answered, such as what causes motor system activation in some cases and not others.

“Imitation is thought to be an important mechanism by which babies and young children learn about the actions and intentions of others,” Fox says. “We intend to build on Courtney’s work to learn about different and more complex forms of imitation and how they relate to the understanding of other people’s goals and intentions.”

Philippi, now a postdoctoral fellow in neuroscience at the National Institutes of Health, says infants’ natural curiosity about what people around them are doing aided the study, while their fabled bounciness complicated it.

“The test requires them to be still and not moving,” she says. “Infants can be challenging because you can’t just give them directions, and often they aren’t interested in staying still.”