At just two or three days old, can a newborn baby recognize the expressions on his or her parents' faces? New research suggests a baby can—provided mom and dad lean in close. A study conducted by researchers at the Institute of Psychology at the University of Oslo in collaboration with colleagues at the University of Uppsala and Eclipse Optics in Stockholm, Sweden, tested adults' ability to perceive faces in motion to come to new conclusions about the visual acuity of newborns.

"Previously, when researchers have tried to estimate exactly what a newborn baby sees, they have invariably used still photos. But the real world is dynamic. Our idea was to use images in motion," explained Svein Magnussen in a press statement.

So what happens to newborns' vision when objects are in motion? Can they tell the difference between a happy smile and an angry scowl?

Illustration by Professor Bruno Laeng/ UiO.

Using as parameters what we know about young babies' sensitivity to visual contrast and spatial resolution, Magnussen tested adult participants' ability to accurately assess facial expressions shown in video clips, which were digitally blurred to reflect how a baby sees. The assumption was that an adult's ability to recognize facial expressions would represent an outer limit for what a newborn might be capable of perceiving.

The study found that when the clips reflected how a baby sees faces up to 30 cm away, the adults were able to accurately judge the expression three out of four times. But when the video was distorted to appear how it does to a newborn at 120 cm, participants' rate of identification dropped to about what one could expect from random responding.

From this, the scientists inferred that it's possible for newborn babies to recognize not just faces, but facial expressions, provided the face in question is not more than 30 cm away—or about the distance between mother and child during nursing.

Possible, but not definite. The researches cautioned that this isn't a guarantee that the babies do recognize facial expressions, just that it's possible that they could, based on their visual parameters. Or, as Magnussen points out, "it's important to remember that we have only investigated what the newborn infant can actually see, not whether they are able to make sense of it."

[h/t Science Daily]