Not long ago, textbooks on child development taught that infants six months and younger didn’t know, or sense, whether something still exists when it is not where the baby can see it. If a parent was in another room, the baby believed that the parent no longer existed, which is called not having “object permanence.”

Through a lot of research, psychologists now know that this is untrue and doesn’t apply to young infants. But how much can babies remember, and what specific information must their brains acquire to keep track of things?

Melissa Kibbe, a postdoctoral researcher at the Department of Psychological and Brain Sciences at the Krieger School of Arts and Sciences at Johns Hopkins, studied this phenomenon, published in the journal Psychological Science. Babies’ brains have built-in ‘pointers.’ Though they can’t remember details of something they were shown and which was then hidden, these ‘pointers’ help them to hold in their brains a memory even when it is not in sight anymore.

Kibble commented, “This study addresses one of the classic problems in the study of infant development: What information do infants need to remember about an object to remember that it still exists once it is out of their view? The answer is, minimal.”

Another discovery is that though babies can’t remember the shapes of two hidden objects, they are surprised when the objects disappear completely. This led the researchers to conclude that infants can remember the existence of something without remembering exactly what that thing is.

Kibbe, who worked on this study while pursuing her doctorate in Leslie's laboratory at Rutgers, highlights the importance of this discovery, saying that it gives an insight into the brain's mechanisms that support memory in infancy and later.

She explains,  “Our results seem to indicate that the brain has a set of ‘pointers’ that it uses to pick out the things in the world that we need to keep track of. The pointer itself doesn't give us any information about what it is pointing to, but it does tell us something is there. Infants use this sense to keep track of objects without having to remember what those objects are.”

They observed that the babies hardly noticed a difference when the objects were swapped, suggesting that they didn’t retain a memory of the object’s shape. In the infant’s mind, a triangle and a disk were virtually identical. When one of these disappeared, the babies were surprised and looked for a more extended period of time at the empty space, suggesting they expected something to be there where they saw something previously. 

Originally posted by John Hopkins University on ScienceDaily