Psychology professor Lauren Emberson has developed a new technique to study how the portions of babies’ brains that respond to visual stimuli are the same portions of babies’ brains that respond to the expectation of a visual stimulus.

The research in “Top-down modulation in the infant brain: Learning-induced expectations rapidly affect the sensory cortex at 6 months,” published June 20 in the Proceedings of the National Academy of Sciences, was conducted by Emberson, Richard Aslin and John Richards.

Aslin is a professor at Rochester University for the Brain and Cognitive Sciences and Center for Visual Science, and Richards is a professor at the University of South Carolina department of psychology.

Emberson, who joined the University psychology department on September 1 as an assistant professor of psychology, was previously a postdoctoral associate at Rochester University for the department of Brain Cognitive Sciences.

Emberson explained that in the study, parents go into a room where there is a screen that will display a video to the baby. A small cap, which utilizes near-infrared spectroscopy, is placed on the baby’s head. The baby is then exposed to a pattern of sounds and images including a clown horn honk or a rattle followed by the image of a smiley face. The sound and visual stimulus were then paired together and shown to the infant. At random periods the sound still occurred, but the image was withheld.

“There was one baby in particular, she had this look when the smiley face did not appear. She had this great surprised look, a ‘where did it go’ kind of look,” Emberson said.

Emberson said that the moment experienced by the baby was a kind of peek-a-boo moment. One in which the baby expected to see something, but did not.

She noted that the experiments performed on the infants ages 5 to 7 months were non-invasive and entirely dependent on the baby’s wanting to participate.

With the aid of John Richards’ anatomical data of baby brains, the researchers were able to localize where the sensors of the babies’ brains are in respect to the underlying anatomy, Aslin said. Emberson explained that they could then determine which parts of the brain were activated by the visual stimulus.

“For a naïve person like an infant, since you can’t tell them the structures that are present they have to figure it out themselves by listening or looking at events that occur in the world. And so that seems to be a very powerful form of implicit learning,” Aslin said.

He explained that the study used an optical technique known as near infrared spectroscopy, in which light of a particular wavelength that can travel through skin and scalp is shined into the brain. The amount of light that comes back out, he said, varies by how much oxygen is being absorbed by the brain at that location, and the amount of oxygen being absorbed is higher when neurons are more active. 

“What it does is provide a measure of how the surface of the brain is responding when you present certain kinds of stimuli to the infant,” he said.

This methodology, he added, is new and particularly suitable for babies.

He also noted that although these kinds of studies have been around for twenty years, what has been missing from most of that work is an understanding of the brain mechanisms that support statistical learning. Emberson’s study, he said, is the first entry point into beginning to understand how statistical learning operates in the brain.

“Developmental science is a relatively new field and Lauren is a pioneer tackling very important theoretical, methodological and statistical challenges,” associate psychology professor at the University Casey Lew-Williams said, regarding the research.