What Lies Behind a Baby's Eyes

We give meaning to our world by categorizing objects. When and how does this process begin? By studying the gaze of a hundred infants, scientists have shown that babies as young as four months old can classify objects they have never seen before as “animate” or “inanimate.” These findings show measurable changes in neural organization that reflect the transition from simply observing the world to understanding it.

What Babies See and Recognize

The way babies view the world is a big mystery. What do they really see? What information do they obtain through sight? One might think that they look at the things that stand out the most—for example, because of their size or color. But when do babies begin to see and interpret the world like adults? To answer this question, researchers at the Institut des Sciences Cognitives Marc Jeannerod (CNRS / Université Claude Bernard Lyon) studied a hundred babies between the ages of 4 and 19 months. The scientists recorded the babies’ eye movements and the duration of their gaze as they looked at pairs of images depicting animate or inanimate objects from eight different categories (e.g., human faces and natural or artificial objects).

The data obtained from eye tracking in babies was compared with measurements of the brain activity of a group of adults, performed using fMRI, to determine the correspondence between the categorical object organization revealed by the babies’ eyes and that mapped onto the visual cortex of the adults. The methodology used in the study demonstrated the transition from visual exploration, which is guided by the salience of objects in the youngest babies, to object representation and the mature categorical organization of the adult brain in older babies. At just four months of age, babies can already distinguish between animate and inanimate objects. For example, they can recognize that a man and a crocodile are more similar to each other as animals than to a tree, which is an inanimate object. This ability seems astonishing, as babies at this age probably do not yet know what a tree or a crocodile is.

Humans are Born With a Neural Organization

Between the ages of 10 and 19 months, refined categories emerge, and infants’ organization of objects into categories increasingly resembles that of the adult brain. Children of this age immediately recognize a soft, furry object with a face as a non-human animal. This study shows that humans are born with a neural organization that predisposes them to represent object categories that are important for their survival. Categorization is the mechanism that allows us to go beyond what we see and make inferences, analogies, and predictions—for example, that this “soft, furry object” is a cat that needs to be fed—and thus to think about the world around us from an early age.