It’s obvious to most people as soon as they set foot in a place they know well—like their childhood bedroom or a former classroom—that place and memory are intimately linked.

A new paper by researchers at Columbia University, Johns Hopkins, and Princeton sheds light on that phenomenon, and helps demonstrate the neural mechanisms behind it. The research paves the way for a better understanding of how new memories can build on top of existing knowledge and what causes us to remember—or forget—events in our lives.

The research, published this month in Nature Human Behavior, was led by Chris Baldassano, a Columbia professor of psychology, Rolando Masís-Obando, a postdoctoral researcher at Johns Hopkins (and the paper’s lead author), and Kenneth A. Norman, a professor at Princeton University.

They found that when participants are in a location they know well, they form stronger memories. The findings suggest that very familiar places create deeper and richer memories for the events that happen there, perhaps because we have such detailed knowledge of that space and can connect new events to the details we already know.

“Spilling a pitcher of water in your own kitchen and soaking your grandmother’s tea cozy, your son’s refrigerator drawing, and your Pomeranian creates a host of personally meaningful elements that lead to a more complex and durable memory,” Baldassano said.

**The Experiment Design: A Virtual Reality “Memory Palace” **

The research team created a digital “memory palace,” a virtual reality building with 23 rooms. To make sure that each room would cause patterns of brain activity that were as different as possible, the rooms had varying shapes, sizes, decorations, and background music, such as a giant dome with floating rocks or a small room with a campfire.

Study participants first got familiar with the palace’s layout by learning games where they explored the space. Twenty-four hours later, participants were shown videos of each room while having their brains imaged by fMRI, allowing researchers to measure their neural response to each room.

After the first MRI measurement, participants re-entered the virtual reality palace. This time, new objects had been placed in each room; participants had 15 minutes to memorize which objects had been placed where. Finally, participants returned to the scanner and tried to remember what each object was and which room it had been in. Based on their brain activity, the researchers could measure how strongly each participant was able to bring to mind the object in each room.

The Findings

The researchers found that people were better at remembering objects that had been placed in the rooms with more stable and clear patterns of brain activity. In other words, when people had built a strong, high quality mental map for a room, the room was more useful for encoding a new memory.

“It’s a bit like assessing the sturdiness of a new foundation,” Masís-Obando said. “We come in, take a few measures, and get a sense of how strong that foundation is. If you want new memories to hang steadily, they need something solid to anchor to.” The findings also suggest that the more distinct a neural impression a specific location has made on us, the more it helps us inscribe memories.

That phenomenon was so pronounced that the researchers could actually predict which objects would be well-remembered even before showing the objects to the participants. If a participant had a poor mental map for a room, then any object placed in that room would be less likely to be strongly remembered later on. This points to the importance of prior knowledge in learning, and suggests that neuro-imaging could even identify “cracks” in this knowledge that should be repaired before trying to attach on new information.

The researchers also found that certain rooms were more memorable across participants. Specifically, small rooms with a window to the outside and many corners were most reliably remembered by study participants.