For most of us, memories of early childhood—particularly before the age of four—are sparse or completely absent. This common phenomenon is known as infantile amnesia, and it affects not only humans but other mammals as well. While we may assume that early memories simply vanish, emerging research suggests the story is more complicated.
A new study reported by Ars Technica highlights growing evidence that infants are capable of forming memories as early as one year old. Using MRI scans, researchers detected memory-related activity in human infants, paralleling findings from earlier experiments in mice.
These animal studies are particularly intriguing. In one experiment, scientists taught young mice to associate a specific environment with a mild shock. While the mice appeared to forget this memory as they aged—consistent with infantile amnesia—researchers were able to later reactivate the memory using genetic tools. This revealed that the memory had not been erased, but merely made inaccessible.
The Genetics of Memory Reactivation
The mechanism behind this involves a protein that, when produced, leads to permanent changes in a second gene inserted into the animal’s DNA. This allowed scientists to effectively “switch on” the hidden memory, suggesting that early experiences are encoded more robustly than previously thought.
What This Could Mean for Humans
If the findings in mice apply to humans, it could mean that our earliest memories are not truly lost—they’re just deeply buried, waiting for the right key to unlock them.
In short, while the traditional explanation for infantile amnesia has been that the brain’s memory systems aren’t fully developed in early life, new evidence hints at a more nuanced picture. Our first experiences may still reside within us, just out of reach.
