Scientists Unravel Why Early Childhood Memories Fade Away
Ever wondered why those first few years of life remain a blank slate, no matter how hard you try to peek back? A fresh study featured in Science, as reported by CNN, suggests it’s not that those memories never existed—it’s that grown-up brains can’t fish them back out.
How the Study Unfolded
Researchers zoned in on 26 infants, aged 4.2 to 24.9 months, splitting them into two camps: under 12 months and 12 to 24 months.
Inside an MRI machine, these little ones watched a parade of unique images flash by, each lasting two seconds. The goal? To catch the hippocampus—the brain’s memory and emotion hub—in action. After a brief pause, the infants faced a pair of pictures: one they’d seen before, one brand new. By tracking their eye movements—lingering gazes signaling recognition—scientists gauged whether those tiny minds could pull up the past.
A longer stare at a familiar image meant memory at work; a shrug between the two hinted at a fuzzier recall, the study notes. Digging deeper, the team compared MRI scans from babies who locked onto familiar sights against those who didn’t pick a favorite.
What They Discovered
The findings lit up a clear pattern: older infants, past their first birthday, showed a livelier hippocampus when locking memories in place. Plus, only they sparked action in the orbitofrontal cortex—a decision-making hotspot tied to memory recognition. “The hippocampus kicked into higher gear for encoding in the older group,” the study highlights, pointing to a developmental leap.
Why the difference? It’s murky, but likely tied to the whirlwind of changes in a baby’s brain. “That early stretch is a whirlwind—perception, language, motor skills, and biology all shift, with the hippocampus ballooning in size,” explained Dr. Nick Turk-Browne, lead author and Yale psychology professor.
The Mystery Lingers
Though infants can encode memories, retrieving them later seems out of reach. Turk-Browne’s team is hot on the trail of why, suspecting the hippocampus can’t quite crack the code to fetch those early snapshots. “It’s like the brain’s search engine doesn’t know the right keywords—those moments are filed away under impressions we felt as babies,” he mused. For now, the quest continues to unlock why our earliest chapters stay lost in time.
