How much do babies remember about the world around them?
New research reveals that even though infants can’t remember the details of an object that has been hidden from view, their brains have built-in “pointers” that help them retain the idea that the object still exists even though they can’t see it anymore.
“This study addresses one of the classic problems in the study of infant development: What information do infants need to remember about an object in order to remember that it still exists once it is out of their view?” said Melissa Kibbe, one of the researchers. “The answer is very little.”
The team found that even though infants can’t remember the shapes of two hidden objects, they are surprised when the objects disappear completely. The conclusion? Infants do remember an object’s existence without remembering what that object is.
This is important, Kibbe explains, because it sheds light on the brain mechanisms that support memory in infancy and beyond.
“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,” said Kibbe.
“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.”
The study also may help researchers establish a more accurate timeline of the mental milestones of infancy and childhood, she said.
In the study, which was published in a recent issue of the journal Psychological Science, six-month-old babies watched as a triangle was placed behind a screen and then as a second object, a disk, was placed behind a different screen. Researchers then removed the first screen to reveal either the expected original triangle, the unexpected disk, or nothing at all.
The team then observed the infants’ reactions, measuring how long they looked at expected versus unexpected outcomes.
When the objects were swapped, the babies seemed to hardly notice a difference, Kibbe said, indicating that they didn’t retain a memory of that object’s shape. In their minds, a triangle and a disk were virtually interchangeable.
However, when one of the objects disappeared, the babies were surprised and gazed longer at the empty space, indicating that they expected something to be where something was before.
Kibbe, a postdoctoral researcher at Johns Hopkins University, collaborated with colleague Alan Leslie at Rutgers University on the study.
“In short, they retained an inkling of the object,” said Leslie.
Source: John Hopkins University