How many times has something like this happened to you? While brushing your teeth, you remember an important phone call that you need to make as soon as you’re done. But by the time you have finished brushing, you walk out of the bathroom, grab your coat and car keys and head out the door… totally forgetting all about that call that you really needed to make.

We all do this—quite often, in fact—and it’s not because we’re getting old and addle-brained. It’s actually something that our brains are hard-wired to do! New research from the University of Notre Dame in Indiana, published in August 2011 in Quarterly Journal of Experimental Psychology, demonstrates what I think is an astonishing—but, as you will see, quite logical—connection between forgetfulness and walking through doorways.

DOORWAYS DRAIN MEMORY

This new study confirms in a “real world” environment what previous research identified in a virtual environment—a phenomenon dubbed the “location-updating effect,” showing that the simple act of passing through a doorway as you move from one room to another raises the likelihood that you’ll forget what you were just thinking about. Why? Gabriel Radvansky, PhD, a professor of psychology at Notre Dame and a coauthor of this study, who has been researching how memory works for most of his career, told me about one of the experiments that his team recently set up that has “opened the door” to understanding how and why this happens.

The experiment: A set of volunteers (28 women and 32 men) were split into groups. Group A walked through a series of three rooms. In the first room, they were asked to place six objects (each a different shape and color) into a box and then cover it up and bring it to the next room. In the second room, after they had gone through a doorway, they were given a computer quiz, asking which objects they had put into the box just a few minutes earlier. Group B did the same thing, except they didn’t walk through a series of rooms, they walked to different spots within the same room—in other words, they didn’t encounter any doorways. The results? Group A—the one that walked through doorways—made 5% more errors on the memory test than Group B.

BOOST YOUR MEMORY

Now, what does this act of walking through doorways mean to our brains? What it is—literally, not metaphorically—is what Dr. Radzansky called an “event boundary” that signals to your brain that your situation has changed. To understand this, think of your mind as being like a filing cabinet. When something changes—whether in time or setting—your brain acknowledges the shift by creating an “event file” as a way of keeping track of your life (without which it would be a mess!). Walking through a doorway is a signal to your brain to put what you were just thinking about into its own file… which makes information from before the location change not quite as readily available to you as it was earlier. Unfortunately, another experiment that was part of the same study done by Dr. Radvansky showed that walking back into the original room that you were in doesn’t trigger recall.

According to Dr. Radvansky, we should think of this location-updating effect as being beneficial. “By creating event boundaries when entering a new space, our minds are getting refreshed, so we’re able to focus on the new environment,” he explained. I have to admit, from that perspective it makes sense. For instance, when my doctor walks through the door to see me, I like knowing that she is no longer thinking about the patient that she just saw!

How can we use this information to improve our memory? One idea is to plan around it by leaving sticky notepads in every room—that way, if an idea comes to you, you can write it down immediately so you don’t forget it. Another idea is to always have your smartphone handy so that you can leave yourself a voicemail or send yourself an e-mail or text. And the next time you walk purposefully into a room and instantly forget what brought you there, don’t fret. It’s probably nothing more than your brain’s overly efficient reset button trying to get you ready for what’s coming next.