Most people don't remember anything before the age of 3, but a new study out of New York University suggests that memories formed in our early years might still be latent in our brains. With the right triggers, those memories might get unlocked, reports New Scientist.
The precise reason that memories from our infancy are lost is a bit of a mystery. Theorists tend to believe that it has something to do with the fact that our brains are still developing in those years, but it's unclear why memory gets sacrificed while other important aspects of our cognition do not. For instance, we start to figure out how to move and communicate in our infant years, as well as figure out what we like and dislike. Memories, certainly, would be useful during this period too, but those memories, to the extent that they are formed at all, quickly fade.
Or do they? Researcher Alessio Travaglia believes that our brains might actually be storing our earliest memories after all, and that they might be able to be revived with the correct stimulus. To investigate, he turned his attention to an unlikely source: rats.
There's reason to believe that rats also experience infantile amnesia, just like us. The rat equivalent of a 2- or 3-year-old child is about 17 days, and until this period of time passes, young rats tend to forget some pretty basic stuff. For instance, lab rats at 17 days old and younger typically forget when a section of their enclosures is capable of shocking them. Older rats, by contrast, learn to stay away.
What Travaglia discovered, however, was that all the younger rats needed was a "reminder" of sorts. If they were shocked twice, their childhood memory would often resurface.
“Suddenly they had the memory back,” he said. "This suggests that the memory is still there, just not normally accessible."
Travaglia's claim is certainly controversial. It's not clear if it's the rats' infantile memory that is resurfacing, or if it's just a new memory that forms due to being unpleasantly double-shocked. Furthermore, it's disputable whether rats even experience infantile amnesia like humans do in the first place. But if the rat experiments do provide an analog, then it means that perhaps it's possible to evoke our infantile memories as well.
Might latent infantile memories be triggered by hypnosis? Or perhaps, when we feel mysteriously triggered by events that force us into "off days," that these are evidence of childhood traumas that are subconsciously lurking in our brains?
At this time there's only a long list of maybes. Travaglia will need a lot more evidence than a rat study to develop his theory, but it's an intriguing start to say the least. In time, perhaps his research will unlock all sorts of ways that our memories can be heightened, revived or perhaps even suppressed.