What is your earliest memory? While you might have one or two specific memories from your very early childhood, most of us don’t have much ability to recall events before about age five or six.
If you have children you likely will have noticed they are quite adept at recalling events in the short term (just try promising a treat in the morning and see if they fail to remind you later that day or the next).
However, long-term memory in young children is another question.
Most young children will not remember a holiday that happened more than a year ago—and of course, by the time we reach adulthood, we tend to have very limited memories of anything that happened in early childhood.
This phenomenon is known as infantile amnesia and the reason behind it has long been a mystery.
Some believe the lack of early childhood memories is linked with verbal development.
Others seem to believe memories exist but are buried.
Within the psychiatric field, some therapists have devoted a lot of time to attempting to help patients unlock early childhood memories—particularly if trauma or abuse were suspected.
However, these techniques have not enjoyed widespread acceptance or success.
Research out of the University of Toronto has begun to shed new light on the topic of infantile amnesia.
These findings indicate that very active brain development and neuron production in early life seems to make long-term memory formation impossible.
Studying younger and older mice, researchers found that if they increased neurogenesis (formation of new neurons) after memory formation, it induced forgetfulness in the mice.
Similarly, decreasing neurogenesis after memory formation in younger mice eliminated normal forgetting. Researchers believe these results could be directly related to how memory works in the human brain.
Neurogenesis in the hippocampus—a brain region important for learning and memory—is at its peak in very young babies and children.
This is not surprising when you consider how much a child learns in the first couple of years of life.
Although the formation of neurons is critical for learning, it also clears the mind of long-term memory.
Storage simply is not a priority for a quickly forming brain.
So contrary to what some believe, it seems likely that early childhood memories are not merely blocked or buried, but likely do not exist.
Our quickly changing hippocampus in early childhood inhibits information storage.
More research into memory formation and neurogenesis will undoubtedly continue to teach us more about this fascinating function of the human brain.