Princeton Psychologist explores expectations in babies’ brains

Many parents are used to playing games such as peek-a-boo with their babies. The reaction once your little child sees your face again – whether it be a giggle, smile or surprised face – is almost always guaranteed. For some time, according to newly hired psychology professor at Princeton University Lauren Emberson, scientists have understood infants’ brains respond to visual stimuli. But what she and a team set out to find at the University of Rochester and South Carolina was to see what happens in the inner-workings of the brain when a baby expects to see something.

“My work really hinges on how babies are using their experiences to develop. Learning, seeing and perceiving the world, understanding language – all of these happen through varying experiences over many months. I think this [idea] is intuitive for every parent,” Emberson said.

 “But we don’t really know how babies use their experience, how it shapes the brain and theoretically where in the brain it occurs.”

To explore these questions, Emberson and her team used near-infrared spectroscopy, a technology that measures oxygenation in regions of the brain using light to assess and record neurological activity, or in layman’s terms, as Emberson explained, “an incredible technology that allows us to take a little peek into babies’ brains in a way that is completely comfortable for them.”

The near-infrared spectroscopy was used in a controlled study where infants strapped on a small cap – one Emberson said was “unfairly cute” on them – that allowed Emberson to record what is happening in both audio and visual parts of the brain. The key was find whether these things go together early on in infant development; infants in the study were between 5 and 7 months of age.

The scientists created a task for two groups of infants. One with a sequential pattern, infants heard a sound such as a clown horn beep followed by a smiley face image that popped up on a screen. The other solely had the smiley face – visual stimuli with no corresponding audio.

After exposing the infants to the sound and image pattern for a few minutes, giving them the opportunity to learn the relationship between the two, Emberson and her team began periodically removing the smiley face image. For the infants who had been exposed to the pattern, brain activity was detected in the visual areas of the brain even when the image didn’t appear as expected. The group without the paired audio-visual relationship did not have that part of the brain activity.

“It was really interesting. A lot of the time the babies would look absolutely shocked when they didn’t see the smiley face come up,” Emberson said. “When babies have learned that sound predicts something, they react with ‘Hey! I wanted to see something there,’ or their brain fires some kind of ‘error’ signal.”

Emberson’s steps in two major directions with these kinds of neurological studies. One is to take information learned in the study, “this captured capsule of learning-based change in the brain,” and question how it is relative to development. The other is to use this information to look at populations at risk for learning development, such as premature babies.

Emeberson explained how her recent move to Princeton is to work in the newly renovated Princeton Baby Lab, where much of this learning development research will take place.

”The lab investigates how young children learn and how their incredible learning abilities support their development. This research depends on the generosity of families in the Princeton community to volunteer their time for a 30 to 45 minutes visit to the lab. Our studies are fun and engaging for children, and include children from 0 to 5 years of age,” Emberson said.

Her hope is utilize these experience-based studies of the brain to predict problems down the line for babies who may have cognitive issues.

For more information about volunteering for a study at the Princeton Baby Lab, visit


About Erica Chayes Wida

Erica Chayes Wida is a writer, mom, and complete zealot when it comes to poetry, paella and globe collections. After graduating with a degree in Anthropology from UCLA, Erica moved to Italy where the seasons and old architecture inspired her journey back to the East Coast. Since then, she and her husband have created a nest egg locally and, over time, developed a rather grand love affair with the town of Princeton. Erica is senior editor at The Princeton Sun and enjoys fulfilling her Princeton affections on a daily basis. | View all posts by Erica Chayes Wida