Over the past month, my daughter, Harper, has become increasingly vocal. Her speech has increased dramatically and she’s amazed her dad and I with how much she is able to remember. Lately, we tell her something just once, or just a couple of times, and she is able to repeat that word and remember it hours and even days later. She’s able to recall her animals and their sounds (cow, chicken, dog, cat, duck, sheep) after being told just once or twice. We even thought her “more” in sign language and some words in Spanish and she was able to recall either after once or twice of just telling her. It’s amazing to think that she’s already a-year-and-a-half and saying phrases such as, “bye, mama” and “hi, doggie.” Until you become a parent, you never truly understand how incredible it is to watch your little baby, now toddler, learn and discover things about the world.
Based on what we have learned during lecture, I started wondering how much of what Harper remembers are implicit memories and how much are explicit memories. As we learned, implicit memories are memories that are recalled without necessarily thinking about them. They are influenced and triggered by previous experiences no matter how long ago they occurred. One way to define implicit memories is by saying that we learn things without awareness—we have that memory stored, but we are not aware that it is a memory. On the other hand, explicit memories involve explicitly retrieving that memory from storage. These types of memories involve actively searching for that memory from the past and recalling it. It shocked me to learn that toddlers do not have explicit memories until they are about three to four years old. In Harper’s case, when we teach her a new word and recalls it weeks after or she sees her sippy cup and remembers that it is usually filled with her, “agua”, she is using her implicit memory.
Remarkably, an article from Today’s Parent mentions that children are actually able to retrieve explicit memories from toddlerhood, however most children forget these memories because they experience something called infantile amnesia. The article mentions that infants are able to experience explicit memories, but are unable to recall them later on in their lives because those explicit memories happened before that child had any language. As children get older, they begin to forget more and more memories from their childhood because of infantile amnesia.
I wonder if Harper will experience this childhood amnesia? Implicit memories are easily recalled because they are automatic, but how will her explicit memories be affected by childhood amnesia? A study done by the Psychology Department at the University of Otago in New Zealand sought to find out more about the childhood amnesia phenomenon. They observed that most children and adults have no recollection of their early childhood. Something that was very puzzling to them was the fact that although learning happens from birth on, yet the memories that are created from this early learning are somehow lost. Here is an excerpt from their findings:
“If forgetting occurs within days or weeks during early infancy, it is hardly surprising that those memories are unavailable when we try to access them after retention intervals of years (or decades)! Over the course of development, however, the forgetting function gradually flattens, increasing the accessibility of a given memory even after very long delays. Furthermore, even after forgetting has occurred, data collected using re- minder procedures has shown that the accessibility of the representation varies dramatically as a function of age. Older infants retrieve their memories more quickly, over longer delays, and once retrieved, maintain them for longer periods of time.”