Sure, you can quickly remember any song you learned during your teenage years, even if it is a decade or so ago. However, when trying to recall your memories as a baby, everything goes zilch. You can still probably remember your 12th birthday but not your 1st or 2nd ones.
Don’t fret, though! Virtually nobody has retained information from the very early childhood. Most of the earliest memories we have are not from ourselves, but recollections coming from photos given or stories told to us by others.
Adults rarely recall any event that happened prior to the age of three, and only have snippets of information about their experiences between the ages of three to seven. This is because of the circumstances called ‘infantile or childhood amnesia.’ It has been a bizarre matter for psychologists for over a century, and things are still quite vague about it.
For instance, you might think that because events transpired a long time ago, memories may have faded through time. But, our brain doesn’t necessarily function like that. Truth to be told, a 50-year-old adult can still have vivid memories of his teenage years, even if it happened over 30 years ago. But, a 13-year old will most likely be unable to recall the events that occurred when he was still a baby even if only 11 years have passed.
It was initially inferred that the reason behind us not remembering early childhood events is the absence of the ability to make such stable memories. We won’t be able to remember anything if it’s not there in the first place.
However, it was soon found out that babies and small children can actually form some memories, both implicit and explicit ones. The former enables us to fulfill tasks or actions without thinking about them while the latter acts when we try to recall events that transpired consciously.
Our capacity to remember information for extensive periods significantly improves as we go through the childhood phase. There were experiments in which children were taught to follow an action. Six-month-olds were able to recall what to do up to 24 hours. Nine-month-olds, on the other hand, was able to remember them around a month later. For those over a year and a half of age, they could recall the action taught to them even after a year has passed.
What is interesting is that a recent study in rats showed that even if there were an evident loss of early episodic memories, its traces stay a considerable period of time and can be awakened by any reminder. This is the same reason behind how trauma during childhood can affect the behaviors of adults and boosts risks for mental disorders.
Upon further studying memory, neuroscientists have found out that infantile amnesia also occurs to animals. Their brains, like that of humans, continually develop after they are born.
A human baby’s brain is roughly around 25% of its adult size at birth. Come to the age of two, it would have grown 75% of its size. This rapid growth is linked to neuron growth, including the testing and removal of circuits.
The hippocampus, the area of the brain responsible for the creation of episodic memories, or those occurrences we’ve experienced, keeps on developing after we are born. It continually produces new neurons as we go into adulthood. The dentate gyrus, for instance, is in full force, creating neurons at an intense rate. After production, neurons are then fused to existing hippocampal connections.
Experts believe that this intense production rate of neurons is the culprit behind us not recalling anything about our childhood. Since new connections are created in the memory circuits, the multitude of newly-produced neurons distorts our already-existing memories.