Infantile amnesia, the inability to remember our first few years of life, is a phenomenon that has stumped researchers for years. We’re still trying to understand the possible causes and mechanisms behind this phenomenon, but new research has shone some light on this. Episodic memory, or remembering the context of when you learned something—like where you were on your wedding day—is thought to be an important component here. The hippocampus is known to be extremely important in the formation and retrieval of episodic memories. On the flip side, this critical brain area doesn’t completely develop until kids are around 2-4 years of age. Therefore, memories acquired in these sensitive years cannot be established because of the hippocampus’s state of development.
Recent research led by work appearing in the journal Science has focused on these inner workings of episodic memory formation. Psychologists recently found that our hippocampus is specially designed to encode the sort of information that’s critical for episodic memory. This aptitude develops as early as the first few years of life. Yet in spite of this remarkable faculty, episodic memory might prove too complicated an enterprise for young children prior to their second year. Starting around 2-3 years old, toddlers start to combine bits of memory together. This policy change enables them to begin documenting the mood swings of their journey.
The research, led by the University of Cambridge, indicates that infantile amnesia may not be so much about young children not being able to retain information. Rather, it underscores our struggle as adults to access those memories down the line. Environmental and contextual factors impact our ability and manner of encoding episodic memories. It is the hippocampus that performs the magic here, linking together bits and pieces of disjointed information into complete, cohesive experiences.
In another study published in Science Advances, researchers discovered that "forgotten" childhood memories could be reinstated in adult mice by using light to stimulate neural pathways. This surprising new discovery shows for the first time that young children’s memories are not entirely gone. Rather, they might remain dormant, only activated when certain conditions aren’t met.
Episodic memory, the ability to remember specific events, is an intricate process. Most importantly, it helps us remember episodic memories, like the sweet scent of a flame on a birthday cake. Our capacity to create these memories is made possible largely by the growth of the hippocampus. As kids get older, their brains get really good at connecting the dots. This experience makes them the best at holding onto and recalling episodic memories.
Researchers dispute what should be the main focus of memory growth in the preschool years. That’s positive feedback. Nora Newcombe, a cognitive psychologist at Temple University in Philadelphia, has a different take. She argues that perhaps in the first two years, education should be more about gaining semantic knowledge, rather than developing episodic memory.
"I think the primary goal of the first two years is to acquire semantic knowledge, and from that point of view, episodic memory might actually be a distraction," said Nora Newcombe.
This perspective highlights the possibility that episodic memory may develop later as children begin to piece together experiences into coherent narratives.
Tomás Ryan, an associate professor of biochemistry at Trinity College Dublin, who led the research, explained the unexpected finding on memory retention. He discussed the lighter, more funny side of forgetting.
"These new findings suggest that immune activation during pregnancy results in an altered brain state that alters our innate, yet reversible 'forgetting switches' that determine whether the forgetting of infant memories will occur," stated Tomás Ryan.
These studies emphasize that acquiring episodic memory is not a straightforward procedure. This process is very much influenced by a host of biological and experiential factors. As studies like this one go on, our scientists will be working to better explain how early childhood experiences build the foundation for lifelong memory formation and retention.
