Have you ever wondered why you can't remember anything from when you were a baby? Scientists at Yale University have made a cool discovery about this mystery!
The Memory Problem
As babies, we learn many essential things - how to walk, talk, and recognize our family. But as adults, we can't remember specific events from our first few years. This is called "infantile amnesia."
For a long time, scientists thought we couldn't remember being babies because the part of our brain that stores memories (called the hippocampus) hadn't developed enough yet. They believed our baby brains couldn't save memories properly. But is that really true? The Yale researchers wanted to find out!
How Do You Study Baby Memories?
Studying baby memories is super tricky. Why? Because babies can't talk to tell us what they remember! The scientists had to get creative.
"How do you know what someone remembers if they can't tell you?" That was the big question facing the research team, which was led by Professor Nick Turk-Browne, who directs Yale's Wu Tsai Institute, and Tristan Yates, a graduate student at the time.
The team devised a clever test. They knew babies tend to look longer at new or surprising things. So if babies recognize something they've seen before, they pay more attention to it the second time.
The Cool Experiment
Here's what the scientists did in their experiment:
They showed babies (aged 4 months to 2 years) pictures of new faces, objects, and scenes.
Later, they showed the babies these same pictures again, but this time next to brand new pictures.
They carefully watched where the babies looked and for how long.
At the same time, they used a special brain scanner called an fMRI to see what was happening inside the babies' brains.
Using brain scanners with babies is super hard! Babies wiggle a lot, can't follow directions like "stay still," and have very short attention spans. The Yale team has spent over ten years figuring out how to do this successfully.
What They Discovered
The results were amazing! The scientists found that when a baby's hippocampus was more active while looking at a picture for the first time, that baby was more likely to stare at it longer when they saw it again later. This means the babies recognized the pictures they had seen before!
Even more interesting, the specific part of the hippocampus that was active in the babies was the exact part that helps adults remember particular events - the posterior (back) part of the hippocampus.
These findings were accurate for all 26 babies in the study, but they were strongest in babies older than 12 months. Half of the babies in the study were older than 1 year, and half were younger.
Two Types of Memory
The scientists also discovered something fascinating about how different types of memory develop.
There are two main kinds of memory that our brains use:
Statistical learning memory: This helps us learn patterns across many events. For example, understanding what a restaurant looks like or learning language patterns. This type of memory develops earlier in babies.
Episodic memory: This helps us remember specific events, like what we had for breakfast this morning or who visited yesterday. The scientists tested this type of memory in the study.
The Yale team found that these two types of memory use different pathways in the hippocampus. The statistical learning pathway develops first in the front part of the hippocampus, while the episodic memory pathway develops later in the back part.
Professor Turk-Browne explains that this makes sense for babies. Learning patterns (statistical learning) help babies understand their world, learn language, and recognize important things. It makes sense that this would develop before the ability to remember specific events.
The Big Mystery: Where Do Baby Memories Go?
The study shows that babies CAN form memories - their brains are saving information better than scientists thought. But this creates a new mystery: If babies can make memories, why can't we remember them when we grow up?
The scientists have two main ideas about what might happen:
Maybe the memories don't get stored for the long term and fade away quickly.
Or perhaps the memories ARE still in our brains, but we can't access them anymore.
The researchers think the second idea might be right - the memories might still exist, but we can't reach them. This suggests that our inability to remember our early years might not be due to a lack of memory formation, but rather an issue with memory retrieval in adults.
What Scientists Are Doing Next
The Yale team is now working on more exciting studies to learn more about baby memories. They're showing children home videos taken when they were babies to see if they can remember events from when they were much younger.
Their early results suggest something interesting: Children might be able to remember things from their baby days until they're about preschool age. After that, the memories seem to fade away.
Professor Turk-Browne and his team are even exploring what seems like a science fiction idea: Could these baby memories still exist in our adult brains, even though we can't access them? This concept, known as 'infantile amnesia', is a wild thought, but science often leads to amazing discoveries!
Why This Matters
This research is important because it changes our understanding of how baby brains work. It shows that the hippocampus starts working much earlier than scientists believed.
Understanding how memory develops can help us learn more about:
How babies grow and learn
How our brains develop
What happens to our earliest memories
Why some memories stay with us, and others don't
The study also shows that there's still so much to learn about our amazing brains, even the tiny brains of babies!
The research was published in the science magazine Science on March 20, 2025. Researchers from Yale University led the study, with Tristan Yates as the lead author.
Fun Facts About Baby Brains
A baby's brain doubles in size in the first year of life!
By age 3, a child's brain has reached about 80% of its adult size.
Babies can recognize their mother's voice from birth.
The connections between brain cells grow super fast during the first few years of life.
Playing, talking, and reading to babies helps their brains develop.
The next time you see a baby learning and exploring the world, remember - their brain is hard at work making memories, even if they won't remember them later!
