Infant Memory Development
What have we discovered about babies’ short-term memory?
Short-term memory is the kind of memory we use when we recognize that an object that is briefly out of sight is the same when it reappears—for example recognizing that a ball that rolls under the couch is the same ball that emerges from the other side (at least if it’s the same color, shape, and size). This kind of memory is critical to see the visual world as unchanging as we blink and move our eyes around. This kind of memory is important for babies—they need to track objects (such as balls and cats) as they move behind furniture and other objects, and they need to be able to connect what they see before and after they blink. In fact, we have discovered that by 4 months babies have this kind of memory—they notice when something changes after it has been out of view momentarily. But, the number of things they can remember this way is extremely limited. We found that 4- and 6-month-old babies remember only one thing. By 10 months, babies remember several things, suggesting that their short-term memory develops extremely rapidly in the first year of life. In general, we have discovered that although short-term memory emerges early in life, it rapidly develops between 4 and 10 months of age. These early limits on short-term memory might be especially important for helping young babies deal with the overwhelming amount of new information they encounter each day.
If infants can store the colors of the squares in memory, they should notice the color changes and look longer at the changing displays. We measure how much infants can remember by varying the number of squares on the screen. We have found that 4- to 6-month-old infants seem to be able to remember only 1 square, whereas 10- to 13-month-old infants seem to be able to remember one of multiple items.