If you’ve ever tried to think back to your earliest memory, chances are you can’t recall much from your first few years of life. Maybe you have a fuzzy recollection of your third birthday, or vague images of a childhood home, but everything before that? It’s like a blank slate. For decades, scientists chalked this up to the fact that the brain’s memory machinery wasn’t fully up and running yet. Specifically, they pointed to the hippocampus—the brain’s memory powerhouse—as a late bloomer, still under construction in early childhood.
But now, groundbreaking research out of Yale University is flipping that long-held belief on its head. A team of scientists has found striking evidence that even in our first year of life, our brains are not only capable of encoding memories but actively doing so. So why don’t we remember them? And what’s really happening in those first fleeting years?
Let’s dive into this fascinating new discovery and explore why it’s reshaping everything we thought we knew about the earliest chapters of our lives.
The Classic Mystery: Why Can’t We Remember Being Babies?
The phenomenon is called infantile amnesia—our universal inability to recall personal events from our infancy. For years, psychologists and neuroscientists believed this blackout was because the hippocampus, the region deep in the brain responsible for forming episodic memories (memories tied to specific events), was still under construction. Without a fully functioning hippocampus, the theory went, young children simply couldn’t form lasting memories.
But if that’s true, why can some preschoolers clearly remember events from when they were toddlers? And why do animals show signs of memory long before their hippocampus matures? There have always been pieces of the puzzle that didn’t quite fit.
Yale’s New Approach: Seeing Memory in Action
To dig deeper into this mystery, a team at Yale University, led by Nick Turk-Browne, professor of psychology and director of Yale’s Wu Tsai Institute, took a fresh approach. Partnering with graduate student Tristan Yates, they set out to test whether infants were forming memories in the first place, rather than relying on what older children (or their parents) could later report.
This posed a serious challenge: infants can’t tell you what they remember. They can’t describe a birthday party, a favorite toy, or even yesterday’s nap. But they can look. And that’s where the magic lies.
The researchers capitalized on infants’ natural tendency to stare longer at things that catch their attention—particularly things they recognize. By using this innate behavior, they could test recognition memory without needing words.
The Experiment: What Babies’ Eyes (and Brains) Revealed
In the study, the team showed infants aged four months to two years a series of new images—faces, objects, scenes. After introducing other images to keep things fresh, they showed the infants a side-by-side pair: one image they’d seen before and one they hadn’t.
The hypothesis was simple: if the infant had a memory of the earlier image, they’d stare at it longer when it reappeared. And that’s exactly what happened. But the Yale team didn’t stop there. They also wanted to see what was happening inside the babies’ brains during all this looking.
Using advanced functional magnetic resonance imaging (fMRI) technology—a technique notoriously difficult to pull off with wiggly, easily distracted babies—they measured activity in the infants’ hippocampus while they viewed the images.
The results were striking. The infants who showed stronger hippocampal activity when first seeing an image were more likely to recognize it later. The more the hippocampus lit up during initial exposure, the longer they stared at that same image when it came back. This wasn’t random—it was clear evidence that their brains were encoding memories.
What’s more, the brain region doing the heavy lifting was the posterior hippocampus, the very area linked with episodic memory in adults. This suggests that the basic building blocks of episodic memory are in place much earlier than previously believed.
The Age Factor: When Does Memory Start Clicking?
Interestingly, the team noticed that this hippocampal encoding was stronger in infants over 12 months old. That’s consistent with the idea that episodic memory systems are still developing in the first year of life and become more robust after the first birthday.
But even younger infants—some as young as four months—were showing hippocampal activity related to memory. The notion that the infant brain is a blank slate just doesn’t hold water anymore.
Two Types of Memory: Episodic vs. Statistical Learning
Turk-Browne’s team has previously studied another type of memory called statistical learning in infants as young as three months old. This is the brain’s ability to detect patterns across experiences. For example, an infant might not recall one specific encounter with a dog, but they learn the general concept of “dog” over repeated exposures. This kind of learning happens in the anterior hippocampus, a region that develops earlier.
Episodic memory, on the other hand, is all about specific events: “That time I saw a dog at the park and it licked my face.” It’s a different kind of mental filing system, one that seems to ramp up later in infancy.
Why Episodic Memory Comes Later—and Why It Makes Sense
Turk-Browne speculates that statistical learning develops first because it’s essential for early survival. Babies need to make sense of their world quickly: language, faces, sounds, and objects. Statistical learning helps build these frameworks.
Episodic memory, while important, isn’t as immediately critical for survival. It comes into play later, once infants have learned the basics of navigating their environment and can start forming narratives about individual events.
So… Where Do Those Early Memories Go?
Here’s the big question: if babies are encoding episodic memories, why don’t we remember them as adults?
Turk-Browne suggests a few possibilities:
- The Memories Fade: Perhaps these early memories don’t get consolidated into long-term storage and simply vanish over time.
- We Can’t Access Them: Another possibility is that the memories are still there, but we lose the ability to retrieve them. This could be due to changes in language, sense of self, or even the way memories are stored in the developing brain.
- They Morph Into Something Else: Some researchers wonder if early episodic memories might get absorbed into more general knowledge over time, stripped of their personal, event-specific details.
Turk-Browne leans toward the second idea—that the memories endure but are inaccessible.
New Clues: Are Our Earliest Memories Still There?
In an ongoing study, Turk-Browne’s team is testing whether young children can recognize home videos taken from their perspective as babies. Preliminary results suggest some of these memories persist until preschool age, after which they become harder to access.
This research hints at an intriguing possibility: the memories from infancy might still be buried in our minds, just locked behind a door we no longer know how to open.
Implications: A Sci-Fi Twist on Infant Memory
The idea that early memories are still in there somewhere has captivated scientists for years. But now, Turk-Browne’s team is exploring whether these early memories can endure into adulthood, even if we can’t consciously access them.
It sounds like science fiction—the notion of unlocking hidden childhood memories. But as techniques like fMRI advance and our understanding of brain development deepens, this once-radical idea is edging closer to reality.
“Tristan’s work in humans is remarkably compatible with recent animal evidence that infantile amnesia is a retrieval problem,” Turk-Browne explains. “We’re beginning to entertain the radical, almost sci-fi possibility that these early memories may endure in some form into adulthood.”
Rewriting the Story of Memory
This new research challenges the traditional narrative that the first years of life are a memory desert. It shows that babies are actively encoding memories, perhaps more than we ever imagined. The puzzle of why we can’t recall these early events may be more about access and retrieval than about the memories never forming in the first place.
As scientists continue to map how memory develops from infancy to adulthood, we may one day find a way to unlock those long-forgotten early experiences. Imagine remembering your very first steps or hearing your mother’s lullaby in vivid detail. It’s a thrilling, humbling reminder of how much we still have to learn about the most mysterious organ in our body—our brain.
For now, this research tells us something profound: the story of who we are begins earlier than we can consciously remember, quietly shaping the foundation of our lives.
Reference: Tristan S. Yates et al, Hippocampal encoding of memories in human infants, Science (2025). DOI: 10.1126/science.adt7570. www.science.org/doi/10.1126/science.adt7570