The brain doesn’t store memories in isolation. Instead, it links weak, easily forgotten experiences to powerful, emotionally charged ones. New research from Boston University, published in Science Advances, explains why you might vividly recall seeing chickens on your way to an awe-inspiring hike. The key: strong memories act as anchors, helping the brain retain even fleeting details.
The Link Between Emotional Impact and Recall
Chenyang (Leo) Lin and his team discovered that the brain ties together related objects and events, even if one is mundane and the other extraordinary. This phenomenon explains why a hiker who was captivated by squirrels in New Hampshire also remembered the chickens he passed on the way. The brain doesn’t compartmentalize; it connects.
How “Tag and Capture” Works
The research builds on the “tag and capture” theory, which suggests that weak memories are temporarily marked on neurons. These tags fade quickly unless reinforced by a stronger memory. When a powerful experience occurs shortly after, it triggers a rush of proteins in the hippocampus—the brain’s memory center. These proteins stabilize the weak memory, essentially gluing it to the stronger one.
The Experiment: Animals, Tools, and Rewards
To test this, Lin’s team asked over 100 participants to view sequences of images: animals (aardvarks, hamsters, sea stars) and everyday tools. Initially, participants simply viewed the images. Then, they were rewarded for correctly labeling them as either animal or tool. Half received high rewards for identifying animals and low rewards for tools, while the other half received the reverse.
The next day, participants were quizzed on the images. Those who received high rewards for identifying animals remembered them better—about 50% compared to 45% for those with low rewards. Surprisingly, high rewards for tools didn’t improve recall; people already remembered them well. The brain seems to categorize memories, linking them within, but not across, categories.
The Implications for Learning and Therapy
This research has implications for how we learn and process trauma. Everyday memories are temporary, but linking them to strong experiences makes them stick. Therapists might use this to reinforce positive memories before or after traumatic events, reducing their impact. Teachers could use unexpected, memorable events to help students retain information. For example, a surprising action in a math problem might help students remember the concept.
The Bigger Picture
“The thing that occurred in the past suddenly takes on more meaning,” notes Joseph Dunsmoor, a cognitive neuroscientist at the University of Texas at Austin. The brain is more receptive to new information after a strong event, making new memories more likely to endure.
Understanding how memories form and link will take further research. However, the findings suggest that by connecting weak memories to strong ones, we can enhance recall, improve learning, and potentially mitigate the impact of trauma
