If you show her a ball or toy, for example, then place it behind your back, you'll see that her eyes follow your action. She seems to remember the object and know where it is. These kinds of observations by parents are borne out by research. The child simply doesn't have the ability to let us know, by reaching for, pointing to, or uncovering the object, that she knows. A baby's capacity for memory expands rapidly.
Some current data suggests that they remember even up to a year later.
Then the infant was encouraged to repeat the activity. What was remarkable, however, was that when the children returned to the institute one year later, they could still recreate the hat. Now, modern brain-imaging techniques have confirmed this notion. Dr. Greenough obtained similar results from his experiments on rats. We found that the brains of rats placed in stimulating surroundings were more elaborate than those of rats placed in isolation.